Mecanismos moleculares de la farmacorresistencia en el cáncer de mama y posibles estrategias para superar la resistencia: Una revisión de la literatura / Molecular mechanisms of drug resistance in breast cancer and potential strategies for overcoming resistance: A literature review

El cáncer de mama es la causa más común de muerte por cáncer en el mundo, y la resistencia a los medicamentos es una de las barreras más importantes para el éxito de la terapia de la enfermedad. Es fundamental tener una comprensión sólida de los procesos moleculares que impulsan la resistencia al tratamiento en el cáncer de mama para diseñar terapias dirigidas con el potencial de superar esta resistencia. Estos mecanismos son complejos y multifacéticos e incluyen la activación de vías de señalización que promueven la supervivencia y proliferación celular, la regulación positiva de las bombas de salida de fármacos, la aparición de células madre cancerosas y cambios genéticos y epigenéticos. Esta revisión de la literatura brinda una descripción general de estos mecanismos y analiza las posibles estrategias para superar la resistencia a los medicamentos en el cáncer de mama, incluido el uso de terapias dirigidas que se dirigen específicamente a las vías y los mecanismos involucrados en la resistencia a los medicamentos. La revisión también destaca la necesidad de más investigación para identificar estrategias efectivas para superar la resistencia a los medicamentos y mejorar los resultados del tratamiento en pacientes con cáncer de mama.

Breast cancer is the most common cause of death from cancer in the world, and drug resistance is one of the most significant barriers to successful therapy for the disease. It is critical to have a solid understanding of the molecular processes driving treatment resistance in breast cancer to design targeted therapies with the potential to overcome this resistance. These complex and multifaceted mechanisms include the activation of signaling pathways that promote cell survival and proliferation, the upregulation of drug efflux pumps, the emergence of cancer stem cells, and genetic and epigenetic changes. This literature review provides an overview of these mechanisms. It discusses potential strategies for overcoming drug resistance in breast cancer, including targeted therapies that specifically target the pathways and mechanisms involved in drug resistance. The review also highlights the need for further research to identify effective strategies for overcoming drug resistance and improving treatment outcomes in breast cancer patients.

Deubiquitinating enzyme MINDY1 is an independent risk factor for the maintenance of stemness and poor prognosis in liver cancer cells / 中华肝脏病杂志

Objective: To explore the key deubiquitinating enzymes that maintain the stemness of liver cancer stem cells and provide new ideas for targeted liver cancer therapy. Methods: The high-throughput CRISPR screening technology was used to screen the deubiquitinating enzymes that maintain the stemness of liver cancer stem cells. RT-qPCR and Western blot were used to analyze gene expression levels. Stemness of liver cancer cells was detected by spheroid-formation and soft agar colony formation assays. Tumor growth in nude mice was detected by subcutaneous tumor-bearing experiments. Bioinformatics and clinical samples were examined for the clinical significance of target genes. Results: MINDY1 was highly expressed in liver cancer stem cells. The expression of stem markers, the self-renewal ability of cells, and the growth of transplanted tumors were significantly reduced and inhibited after knocking out MINDY1, and its mechanism of action may be related to the regulation of the Wnt signaling pathway. The expression level of MINDY1 was higher in liver cancer tissues than that in adjacent tumors, which was closely related to tumor progression, and its high expression was an independent risk factor for a poor prognosis of liver cancer. Conclusion: The deubiquitinating enzyme MINDY1 promotes stemness in liver cancer cells and is one of the independent predictors of poor prognosis in liver cancer.

LIMP-2 enhances cancer stem-like cell properties by promoting autophagy-induced GSK3β degradation in head and neck squamous cell carcinoma / 国际口腔科学杂志·英文版

Cancer stem cell-like cells (CSCs) play an integral role in the heterogeneity, metastasis, and treatment resistance of head and neck squamous cell carcinoma (HNSCC) due to their high tumor initiation capacity and plasticity. Here, we identified a candidate gene named LIMP-2 as a novel therapeutic target regulating HNSCC progression and CSC properties. The high expression of LIMP-2 in HNSCC patients suggested a poor prognosis and potential immunotherapy resistance. Functionally, LIMP-2 can facilitate autolysosome formation to promote autophagic flux. LIMP-2 knockdown inhibits autophagic flux and reduces the tumorigenic ability of HNSCC. Further mechanistic studies suggest that enhanced autophagy helps HNSCC maintain stemness and promotes degradation of GSK3β, which in turn facilitates nuclear translocation of β-catenin and transcription of downstream target genes. In conclusion, this study reveals LIMP-2 as a novel prospective therapeutic target for HNSCC and provides evidence for a link between autophagy, CSC, and immunotherapy resistance.

Casticin Attenuates Stemness in Cervical Cancer Stem-Like Cells by Regulating Activity and Expression of DNMT1 / 中国结合医学杂志

OBJECTIVE@#To explore whether casticin (CAS) suppresses stemness in cancer stem-like cells (CSLCs) obtained from human cervical cancer (CCSLCs) and the underlying mechanism.@*METHODS@#Spheres from HeLa and CaSki cells were used as CCSLCs. DNA methyltransferase 1 (DNMT1) activity and mRNA levels, self-renewal capability (Nanog and Sox2), and cancer stem cell markers (CD133 and CD44), were detected by a colorimetric DNMT activity/inhibition assay kit, quantitative real-time reverse transcription-polymerase chain reaction, sphere and colony formation assays, and immunoblot, respectively. Knockdown and overexpression of DNMT1 by transfection with shRNA and cDNA, respectively, were performed to explore the mechanism for action of CAS (0, 10, 30, and 100 nmol/L).@*RESULTS@#DNMT1 activity was increased in CCSLCs compared with HeLa and CaSki cells (P<0.05). In addition, HeLa-derived CCSLCs transfected with DNMT1 shRNA showed reduced sphere and colony formation abilities, and lower CD133, CD44, Nanog and Sox2 protein expressions (P<0.05). Conversely, overexpression of DNMT1 in HeLa cells exhibited the oppositive effects. Furthermore, CAS significantly reduced DNMT1 activity and transcription levels as well as stemness in HeLa-derived CCSLCs (P<0.05). Interestingly, DNMT1 knockdown enhanced the inhibitory effect of CAS on stemness. As expected, DNMT1 overexpression reversed the inhibitory effect of CAS on stemness in HeLa cells.@*CONCLUSION@#CAS effectively inhibits stemness in CCSLCs through suppression of DNMT1 activation, suggesting that CAS acts as a promising preventive and therapeutic candidate in cervical cancer.

The expression and function of PD-L1 in CD133(+) human liver cancer stem-like cells / 中华肿瘤杂志

Objective: To investigate the expression of programmed death protein-ligand 1 (PD-L1) in liver cancer stem-like cells (LCSLC) and its effect on the characteristics of tumor stem cells and tumor biological function, to explore the upstream signaling pathway regulating PD-L1 expression in LCSLC and the downstream molecular mechanism of PD-L1 regulating stem cell characteristics, also tumor biological functions. Methods: HepG2 was cultured by sphere-formating method to obtain LCSLC. The expressions of CD133 and other stemness markers were detected by flow cytometry, western blot and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect the expressions of stemness markers and PD-L1. The biological functions of the LCSLC were tested by cell function assays, to confirm that the LCSLC has the characteristics of tumor stem cells. LCSLC was treated with cell signaling pathway inhibitors to identify relevant upstream signaling pathways mediating PD-L1 expression changes. The expression of PD-L1 in LCSLC was down regulated by small interfering RNA (siRNA), the expression of stem cell markers, tumor biological functions of LCSLC, and the changes of cell signaling pathways were detected. Results: Compared with HepG2 cells, the expression rate of CD133 in LCSLC was upregulated [(92.78±6.91)% and (1.40±1.77)%, P<0.001], the expressions of CD133, Nanog, Oct4A and Snail in LCSLC were also higher than those in HepG2 cells (P<0.05), the number of sphere-formating cells increased on day 7 [(395.30±54.05) and (124.70±19.30), P=0.001], cell migration rate increased [(35.41±6.78)% and (10.89±4.34)%, P=0.006], the number of transmembrane cells increased [(75.77±10.85) and (20.00±7.94), P=0.002], the number of cloned cells increased [(120.00±29.51) and (62.67±16.77), P=0.043]. Cell cycle experiments showed that LCSLC had significantly more cells in the G(0)/G(1) phase than those in HepG2 [(54.89±3.27) and (32.36±1.50), P<0.001]. The tumor formation experiment of mice showed that the weight of transplanted tumor in LCSLC group was (1.32±0.17)g, the volume is (1 779.0±200.2) mm(3), were higher than those of HepG2 cell [(0.31±0.06)g and (645.6±154.9)mm(3), P<0.001]. The expression level of PD-L1 protein in LCSLC was 1.88±0.52 and mRNA expression level was 2.53±0.62, both of which were higher than those of HepG2 cells (P<0.05). The expression levels of phosphorylation signal transduction and transcription activation factor 3 (p-STAT3) and p-Akt in LCSLC were higher than those in HepG2 cells (P<0.05). After the expression of p-STAT3 and p-Akt was down-regulated by inhibitor treatment, the expression of PD-L1 was also down-regulated (P<0.05). In contrast, the expression level of phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2) in LCSLC was lower than that in HepG2 cells (P<0.01), there was no significant change in PD-L1 expression after down-regulated by inhibitor treatment (P>0.05). After the expression of PD-L1 was knockdown by siRNA, the expressions of CD133, Nanog, Oct4A and Snail in LCSLC were decreased compared with those of siRNA-negative control (NC) group (P<0.05). The number of sphere-formating cells decreased [(45.33±12.01) and (282.00±29.21), P<0.001], the cell migration rate was lower than that in siRNA-NC group [(20.86±2.74)% and (46.73±15.43)%, P=0.046], the number of transmembrane cells decreased [(39.67±1.53) and (102.70±11.59), P=0.001], the number of cloned cells decreased [(57.67±14.57) and (120.70±15.04), P=0.007], the number of cells in G(0)/G(1) phase decreased [(37.68±2.51) and (57.27±0.92), P<0.001], the number of cells in S phase was more than that in siRNA-NC group [(30.78±0.52) and (15.52±0.83), P<0.001]. Tumor formation in mice showed that the tumor weight of shRNA-PD-L1 group was (0.47±0.12)g, the volume is (761.3±221.4)mm(3), were lower than those of shRNA-NC group [(1.57±0.45)g and (1 829.0±218.3)mm(3), P<0.001]. Meanwhile, the expression levels of p-STAT3 and p-Akt in siRNA-PD-L1 group were decreased (P<0.05), while the expression levels of p-ERK1/2 and β-catenin did not change significantly (P>0.05). Conclusion: Elevated PD-L1 expression in CD133(+) LCSLC is crucial to maintain stemness and promotes the tumor biological function of LCSLC.

Trk Inhibition Reduces Tumorsphere Formation and Changes Expression of Stemness Markers in SK-ES-1 Ewing Sarcoma Cells / Inibição de Trk Reduz a Formação de Tumoresferas e Modifica a Expressão de Marcadores Tronco Tumorais em Células de Sarcoma de Ewing SK-ES-1 / Inhibición de Trk Reduce la Formación de Esferoides Tumorales y Cambia la Expresión de Marcadores de Stemness en Células de Sarcoma de Ewing SK-ES-1

Introduction: Ewing sarcoma (ES) is a highly aggressive type of childhood cancer characterized by a chromosomal translocation resulting in fusions between the gene encoding EWS RNA Binding Protein 1 (EWSR1) and one gene of the ETS family, most frequently FLI-1, resulting in the EWS-FLI1 aberrant transcription factor. ES tumors can contain a subpopulation of cells showing cancer stem cell (CSC) features, which express stemness markers including CD133, OCT4 (Octamer-binding transcription factor 4), and NANOG, and display capacity to form tumorspheres likely enriched in CSCs. Neurotrophin (NT) receptors of the tropomyosin receptor kinase (Trk) family (TrkA, TrkB, and TrkC) may play a role in stimulating ES progression, but their possible role in CSCs remains unknown. Objective: To verify the effect of Trks inhibition on the formation of tumorspheres as well as the gene expression of stem markers. Method: The cells were dissociated and the formation of spheres was induced with supplemented culture medium and the K252a treatment was performed. After RNA extraction, mRNA expression levels of target genes Prom1 (CD133), OCT4 (POU5F1), SOX2, and Musashi-1 (MSI1) were analyzed by qPCR. Results: The pan-Trk inhibitor K252a (100 or 500 mM) hindered tumorsphere formation in human SK-ES-1 ES cell cultures. K252a also reduced mRNA expression of Prom1 (CD133-coding gene) while enhancing expression of OCT4. No changes in mRNA levels of SOX2 or Musashi-1 were observed. Conclusion: These findings provide the first evidence suggesting that Trk activity can influence stemness in ES cells

Introdução: O sarcoma de Ewing (SE) é um tipo altamente agressivo de câncer infantil caracterizado por uma translocação cromossômica que resulta em fusões entre o gene que codifica a proteína de ligação a RNA EWS 1 (EWSR1) e um gene da família ETS, mais frequentemente o FLI-1, resultando no fator de transcrição aberrante EWS-FLI1. Os tumores de SE podem conter uma subpopulação de células com características de células-tronco tumorais (CTT), que expressam marcadores de pluripotência como CD133, OCT4 e NANOG, e têm a capacidade de formar esferas tumorais provavelmente enriquecidas em CTT. Os receptores de neurotrofinas (NT) da família de receptor de quinase de tropomiosina (Trk) (TrkA, TrkB e TrkC) podem desempenhar um papel no estímulo à progressão do SE, mas seu possível papel nas CTT permanece desconhecido. Objetivo: Verificar o efeito da inibição dos Trk na formação de tumoresferas, bem como na expressão gênica de marcadores de pluripotência. Método: As células foram dissociadas, a formação de esferas com meio de cultura suplementado foi induzida e realizou-se o tratamento com K252a. Após a extração de RNA, os níveis de expressão de mRNA dos genes-alvo Prom1 (CD133), OCT4 (POU5F1), SOX2 e Musashi-1 (MSI1) foram analisados por qPCR. Resultados: O inibidor pan-Trk K252a (100 ou 500 mM) impediu a formação de esferas tumorais em culturas de células de SE humanas SK-ES-1. O K252a também reduziu a expressão de mRNA de Prom1 (o gene que codifica CD133), enquanto aumentou a expressão de OCT4. Não foram observadas mudanças nos níveis de mRNA de SOX2 ou Musashi-1. Conclusão: Essas descobertas fornecem as primeiras evidências, sugerindo que a atividade dos Trk possa influenciar a pluripotência nas células de SE

Introducción: El sarcoma de Ewing (SE) es un tipo de cáncer infantil altamente agresivo caracterizado por una translocación cromosómica que resulta en fusiones entre el gen que codifica la proteína de unión a RNA EWS 1 (EWSR1) y un gen de la familia ETS, más frecuentemente FLI-1, lo que resulta en el factor de transcripción aberrante EWS-FLI1. Los tumores del SE pueden contener una subpoblación de células que presentan características de células madre cancerosas (CMC), las cuales expresan marcadores de pluripotencia como CD133, OCT4 y NANOG, y muestran la capacidad de formar esferas tumorales probablemente enriquecidas en CMC. Los receptores de neurotrofinas (NT) de la familia del receptor de quinasa de tropomiosina (Trk) (TrkA, TrkB y TrkC) podrían desempeñar un papel en el estímulo de la progresión del SE, pero su posible papel en las CMC aún es desconocido. Objetivo: Verificar el efecto de la inhibición de los Trk en la formación de esferoides tumorales, así como en la expresión génica de marcadores de pluripotencia. Método: Las células fueron disociadas e inducidas a formar esferas con un medio de cultivo suplementado y se realizó el tratamiento con K252a. Después de la extracción de ARN, los niveles de expresión de ARNm de los genes objetivo Prom1 (CD133), OCT4 (POU5F1), SOX2 y Musashi-1 (MSI1) se analizaron mediante qPCR. Resultados: El inhibidor pan-Trk K252a (100 o 500 mM) evitó la formación de esferas tumorales en cultivos de células de SE humanas SK-ES-1. El K252a también redujo la expresión de ARNm de Prom1 (el gen que codifica CD133), mientras que aumentaba la expresión de OCT4. No se observaron cambios en los niveles de ARNm de SOX2 o Musashi-1. Conclusión: Estos hallazgos proporcionan las primeras evidencias que sugieren que la actividad de Trk puede influir en la pluripotencia en las células del SE

RGD peptide inhibits tumor growth by affecting angiogenesis related signaling pathway of laryngeal cancer stem cells / El péptido RGD inhibe el crecimiento tumoral al afectar la vía de señalización relacionada con la angiogénesis de las células madre del cáncer de laringe

SUMMARY: This study is to investigate the role and mechanism of RGD peptide in laryngeal cancer stem cells (CSCs). Laryngeal cancer CD133+Hep-2 CSCs were sorted by flow cytometry. RGD peptide was co-cultured with sorted laryngeal CSCs. Cell proliferation was detected with CCK-8 assay. The mRNA levels of VEGF/VEGFR2/STAT 3/HIF-1α were detected with RT-PCR. The proteins of VEGF/ VEGFR2/STAT 3/HIF-1α were detected with Western blot. The sorted CSCs were inoculated into nude mice. Tumor volume was measured. Integrin αvβ3 expression in tumor tissues was analyzed with immunohistochemistry. The results showed that the ratio of CD133+ CSCs to the total number of cells was 1.34±0.87 %, while CD133-non-tumor stem cells accounted for 95.0±5.76 %. The sorted cancer stem cells grew well. The RGD peptide significantly inhibited the proliferation of CD133+Hep-2 laryngeal CSCs in a dose-dependent manner. The RGD peptide significantly inhibited the mRNA of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a concentration-dependent manner. Consistently, the RGD peptide significantly inhibited the protein expression of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a dose-dependent manner. At the same time, in vivo tumor experiments showed that the RGD peptide significantly inhibited tumor volume but not the body weight. Furthermore, RGD peptide significantly inhibited the expression of tumor angiogenesis-related protein integrin αvβ3. Our findings demonstrate that RGD peptide inhibits tumor cell proliferation and tumor growth. The underlying mechanism may that RGD inhibits tumor angiogenesis-related signaling pathways, thus affecting the tumor angiogenesis, and decreasing the progression of human laryngeal CSCs.

Este estudio se realizó para investigar el papel y el mecanismo del péptido RGD en las células madre del cáncer de laringe (CSC). Las CSC CD133+Hep-2 de cáncer de laringe se clasificaron mediante citometría de flujo. El péptido RGD se cocultivó con CSC laríngeas clasificadas. La proliferación celular se detectó con el ensayo CCK-8. Los niveles de ARNm de VEGF/VEGFR2/ STAT 3/HIF-1α se detectaron con RT-PCR. Las proteínas de VEGF/ VEGFR2/STAT 3/HIF-1α se detectaron con Western blot. Las CSC clasificadas se inocularon en ratones nudos. Se midió el volumen del tumor. La expresión de integrina αvβ3 en tejidos tumorales se analizó con inmunohistoquímica. Los resultados mostraron que la proporción de CSC CD133+ con respecto al número total de células fue de 1,34 ± 0,87 %, mientras que las células madre no tumorales CD133 representaron el 95,0 ± 5,76 %. Las células madre cancerosas clasificadas crecieron bien. El péptido RGD inhibió significativamente la proliferación de CSC laríngeas CD133+Hep-2 de una manera dependiente de la dosis. El péptido RGD inhibió significativamente el ARNm de VEGFR2, STAT3 y HIF-1α en CSC laríngeas de manera dependiente de la concentración. De manera consistente, el péptido RGD inhibió significativamente la expresión proteica de VEGFR2, STAT3 y HIF-1α en CSC laríngeas, de manera dependiente de la dosis. Al mismo tiempo, los experimentos con tumores in vivo mostraron que el péptido RGD inhibía significativamente el volumen del tumor pero no el peso corporal. Además, el péptido RGD inhibió significativamente la expresión de la proteína integrina αvβ3 relacionada con la angiogénesis tumoral. Nuestros hallazgos demuestran que el péptido RGD inhibe la proliferación de células tumorales y el crecimiento tumoral. El mecanismo subyacente puede ser que RGD inhiba las vías de señalización relacionadas con la angiogénesis tumoral, afectando así la angiogénesis tumoral y disminuyendo la progresión de las CSC laríngeas humanas.

Expansion of cord blood stem cells in fibronectin-coated microfluidic bioreactor

ABSTRACT Background: Hematopoietic stem/progenitor cell transplantation is the main treatment option for hematological malignancies and disorders. One strategy to solve the problem of low stem cell doses used in transplantation is pre-transplant expansion. We hypothesized that using fibronectin-coated microfluidic channels would expand HSPCs and keep self-renewal potential in a three-dimensional environment, compared to the conventional method. We also compared stem cell homing factors expression in microfluidic to conventional cultures. Materials and methods: A microfluidic device was created and characterized by scanning electron microscopy. The CD133+ cells were collected from cord blood and purified. They were subsequently cultured in 24-well plates and microfluidic bioreactor systems using the StemSpan serum-free medium. Eventually, we analyzed cell surface expression levels of the CXCR4 molecule and CXCR4 mRNA expression in CD133+ cells cultured in different systems. Results: The expansion results showed significant improvement in CD133+ cell expansion in the microfluidic system than the conventional method. The median expression of the CXCR4 in the expanded cell was lower in the conventional system than in the microfluidic system. The CXCR4 gene expression up-regulated in the microfluidic system. Conclusion: Utilizing microfluidic systems to expand desired cells effectively is the next step in cell culture. Comparative gene expression profiling provides a glimpse of the effects of culture microenvironments on the genetic program of HSCs grown in different systems.

Advances in research of Musashi2 in solid tumors / 南方医科大学学报

RNA binding protein (RBP) plays a key role in gene regulation and participate in RNA translation, modification, splicing, transport and other important biological processes. Studies have shown that abnormal expression of RBP is associated with a variety of diseases. The Musashi (Msi) family of mammals is an evolutionarily conserved and powerful RBP, whose members Msi1 and Msi2 play important roles in the regulation of stem cell activity and tumor development. The Msi family members regulate a variety of biological processes by binding and regulating mRNA translation, stability and downstream cell signaling pathways, and among them, Msi2 is closely related to embryonic growth and development, maintenance of tumor stem cells and development of hematological tumors. Accumulating evidence has shown that Msi2 also plays a crucial role in the development of solid tumors, mainly by affecting the proliferation, invasion, metastasis and drug resistance of tumors, involving Wnt/β-catenin, TGF-β/SMAD3, Akt/mTOR, JAK/STAT, Numb and their related signaling pathways (Notch, p53, and Hedgehog pathway). Preclinical studies of Msi2 gene as a therapeutic target for tumor have achieved preliminary results. This review summarizes the molecular structure, physiological function, role of Msi2 in the development and progression of various solid tumors and the signaling pathways involved.

Lung Cancer Stem-like Cells and Drug Resistance / 中国肺癌杂志

Lung cancer remains the leading cause of cancer-related death world-wide. Therapy resistance and relapse are considered major reasons contributing to the poor survival rates of lung cancer. Accumulated evidences have demonstrated that a small subpopulation of stem-like cells existed within lung cancer tissues and cell lines, possessing the abilities of self-renewal, multipotent differentiation and unlimited proliferation. These lung cancer stem-like cells (LCSCs) can generate tumors with high effeciency in vivo, survive cytotoxic therapies, and eventually lead to therapy resistance and recurrence. In this review, we would like to present recent knowledges on LCSCs, including the origins where they come from, the molecular features to identify them, and key mechanisms for them to survive and develop resistance, in order to provide a better view for targeting them in future clinic.
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Targeted killing of CD133+ lung cancer stem cells using paclitaxel-loaded PLGA-PEG nanoparticles with CD133 aptamers / 南方医科大学学报

OBJECTIVE@#To construct a polylactic acid-glycolic acid-polyethylene glycol (PLGA-PEG) nanocarrier (N-Pac-CD133) coupled with a CD133 nucleic acid aptamer carrying paclitaxel for eliminating lung cancer stem cells (CSCs).@*METHODS@#Paclitaxel-loaded N-Pac-CD133 was prepared using the emulsion/solvent evaporation method and characterized. CD133+ lung CSCs were separated by magnetic bead separation and identified for their biological behaviors and gene expression profile. The efficiency of paclitaxel-loaded N-Pac-CD133 for targeted killing of lung cancer cells was assessed in vitro. SCID mice were inoculated with A549 cells and received injections of normal saline, empty nanocarrier linked with CD133 aptamer (N-CD133), paclitaxel, paclitaxel-loaded nanocarrier (N-Pac) or paclitaxel-loaded N-Pac-CD133 (n=8, 5 mg/kg paclitaxel) on days 10, 15 and 20, and the tumor weight and body weight of the mice were measured on day 40.@*RESULTS@#Paclitaxel-loaded N-Pac-CD133 showed a particle size of about 100 nm with a high encapsulation efficiency (>80%) and drug loading rate (>8%), and was capable of sustained drug release within 48 h. The CD133+ cell population in lung cancer cells showed the characteristic features of lung CSCs, including faster growth rate (30 days, P=0.001) and high expressions of tumor stem cell markers OV6(P < 0.001), CD133 (P=0.001), OCT3/4 (P=0.002), EpCAM (P=0.04), NANOG (P=0.005) and CD44 (P=0.02). Compared with N-Pac and free paclitaxel, paclitaxel-loaded N-Pac-CD133 showed significantly enhanced targeting ability and cytotoxicity against lung CSCs in vitro (P < 0.001) and significantly reduced the formation of tumor spheres (P < 0.001). In the tumor-bearing mice, paclitaxel-loaded N-Pac-CD133 showed the strongest effects in reducing the tumor mass among all the treatments (P < 0.001).@*CONCLUSION@#CD133 aptamer can promote targeted delivery of paclitaxel to allow targeted killing of CD133+ lung CSCs. N-Pac-CD133 loaded with paclitaxel may provide an effective treatment for lung cancer by targeting the lung cancer stem cells.

Brain Tumor Heterogeneity

Tumor heterogeneity is the concept that different tumor cells provide distinct biomorphological lesions, gene expressions, proliferation, microenvironment and graduated capacity of metastatic lesions. Brain tumor heterogeneity has been recently discussed about the interesting interaction of chronic inflammation, microenvironment, epigenetics and glioma steam cells. Brain tumors remain a challenge with regards to medication and disease, due to the lack of treatment options and unsatisfactory results. These results might be the result of the brain tumor heterogeneity and its multiple resistance mechanisms to chemo and radiotherapy.

Are stem cell marker expression and cd133 analysis relevant to differentiate colorectal cancer? / A expressão de marcadores de células-tronco e a análise do cd133 são relevantes na diferenciação do câncer colorretal?

ABSTRACT Background: CD133 and AXL have been described as cancer stem cell markers, and c-MYC as a key regulatory cellular mechanism in colorectal cancer (CRC). Aim: Evaluate the prognostic role of the biomarkers CD133, AXL and c-MYC and their association with clinicopathologic characteristics in colorectal adenocarcinomas and adenomas. Methods: A total of 156 patients with UICC stage I-IV adenocarcinomas (n=122) and adenomas (n=34) were analyzed. Tissue microarrays (TMA) from primary tumors and polyps for CD133, c-MYC and AXL expression were performed and analyzed for their significance with clinicopathologic characteristics. Results: Poorly differentiated adenocarcinomas and disease progression were independent risk factors for poor overall survival. The median overall survival time was 30 months. Positive CD133 expression (35.9% of all cases), particularly of right-sided CRCs (44.8% of the CD133+ cases), was negatively correlated with death in the univariate analysis, which did not reach significance in the multivariate analysis. c-MYC (15.4% of all cases) was predominantly expressed in advanced-stage patients with distant (non-pulmonary/non-hepatic) metastasis. AXL expression was found only occasionally, and predominantly dominated in adenomas, with less penetrance in high-grade dysplasia. Conclusions: CD133 expression was not associated with inferior overall survival in CRC. While AXL showed inconclusive results, c-MYC expression in primary CRCs was associated with distant metastasis.

RESUMO Racional: CD133 e AXL são descritos na literatura como marcadores de células-tronco tumorais, e c-MYC cumpre papel chave como mecanismo de regulação celular no câncer colorretal (CCR). Objetivo: Avaliar o papel prognóstico dos biomarcadores CD133, AXL e c-MYC e sua associação com características clinicopatológicas de adenocarcinomas e adenomas colorretais. Métodos: Um total de 156 pacientes com adenocarcinomas de estádio UICC I-IV (n=122) e adenomas (n=34) colorretais foram avaliados. Microarranjos teciduais (TMA) dos tumores primários e adenomas foram realizados em busca de expressão de CD133, c-MYC e AXL, com posterior análise de relação significativa com características clinicopatológicas. Resultados: Adenocarcinomas pobremente diferenciados e progressão de doença foram fatores de risco independentes para má sobrevida global. A taxa mediana de sobrevida global foi de 30 meses. Expressão positiva de CD133 (35,9% dos casos), particularmente em cânceres de cólon direito (44,8% dos casos CD133+), correlacionou-se negativamente com óbito na análise univariada, sem significância estatística na análise multivariada. c-MYC (15,4% dos casos) teve predomínio de expressão em pacientes com estádio avançado com metástases distantes (não-pulmonares/não-hepáticas). Expressão de AXL foi pouco encontrada, com predomínio em adenomas, com menor penetrância em displasia de alto grau. Conclusão: Expressão de CD133 não se associou com sobrevida global inferior em CCR. Enquanto AXL demonstrou resultados inconclusivos, expressão de c-MYC em tumores primários se associou-se à metástases à distância.

Molecular markers and mechanisms for stemness maintenance of liver cancer stem cells: a review / 生物工程学报

Primary liver cancer (PLC) is an aggressive tumor and prone to metastasize and recur. According to pathological features, PLC are mainly categorized into hepatocellular carcinoma, intrahepatic cholangiocarcinoma, mixed hepatocellular cholangiocarcinoma, and fibrolamelic hepatocellular carcinoma, etc. At present, surgical resection, radiotherapy and chemotherapy are still the main treatments for PLC, but the specificities are poor and the clinical effects are limited with a 5-year overall survival rate of 18%. Liver cancer stem cells (LCSCs) are a specific cell subset existing in liver cancer tissues. They harbor the capabilities of self-renewal and strong tumorigenicity, driving tumor initiation, metastasis, drug resistance and recurrence of PLC. Therefore, the identification of molecular markers and the illustration of mechanisms for stemness maintenance of LCSCs can not only reveal the molecular mechanisms of PLC tumorigenesis, but also lay a theoretical foundation for the molecular classification, prognosis evaluation and targeted therapy of PLC. The latest research showed that the combination of 5-fluorouracil and CD13 inhibitors could inhibit the proliferation of CD13+ LCSCs, thereby reducing overall tumor burden. Taken together, LCSCs could be the promising therapeutic targets of PLC in the future. This review summarizes the latest progress in molecular markers, mechanisms for stemness maintenance and targeted therapies of LCSCs.

Progress on the role of reactive oxygen species-mediated tumor microenvironment in pancreatic cancer / 生理学报

Pancreatic cancer (PC) is a devastating malignant tumor with high incidence and mortality rate worldwide. Meanwhile, the surgical approaches and drugs of this disease remain challenging. In recent years, reactive oxygen species (ROSs) study has become a hotspot in the field of PC research. ROSs may regulate tumor mic roenvironment (TME), cancer stem cells (CSCs) renewal and epithelial-mesenchymal transition (EMT), which result in drug-resistance and recurrence of the PC. Currently, TME that includes immune infiltrates, fibroblasts, vascular vessels and extracellular matrix has become a hotspot in the cancer research. Meanwhile, numerous researches have shown that ROSs-mediated TME plays a central role in the occurrence and development of PC. Targeting ROSs may be promising therapeutic treatments for the PC patients. Therefore, the purposes of the review were manifold: (1) to summarize the regulations of ROSs in tumorigenesis and drug-resistance of PC; (2) to investigate the modulation of ROSs in signaling cascades in PC; (3) to study the effects of ROSs in stromal cells in PC; (4) to generalize the potent therapies targeting ROSs in PC. Overall, this review summarized the current status of ROSs in PC research and suggested some potential anti-PC drugs that may target ROSs.

Dysregulation of MAD2L1/CAMK2A/PTTG1 Gene Cluster Maintains the Stemness Characteristics of Uterine Corpus Endometrial Carcinoma / 中国医学科学院学报

Objective To study the stemness characteristics of uterine corpus endometrial carcinoma(UCEC)and its potential regulatory mechanism.Methods Transcriptome sequencing data of UCEC was obtained from The Cancer Genome Atlas.Gene expression profile was normalized by edgeR package in R3.5.1.A one-class logistic regression machine learning algorithm was employed to calculated the mRNA stemness index(mRNAsi)of each UCEC sample.Then,the prognostic significance of mRNAsi and candidate genes was evaluated by survminer and survival packages.The high-frequency sub-pathways mining approach(HiFreSP)was used to identify the prognosis-related sub-pathways enriched with differentially expressed genes(DEGs).Subsequently,a gene co-expression network was constructed using WGCNA package,and the key gene modules were analyzed.The clusterProfiler package was adopted to the function annotation of the modules highly correlated with mRNAsi.Finally,the Human Protein Atlas(HPA)was retrieved for immunohistochemical validation.Results The mRNAsi of UCEC samples was significantly higher than that of normal tissues(

Expression, purification and characterization of anti-α2δ1/NanoLuc fusion protein / 生物工程学报

The existence of cancer stem cells is regarded as the major cause for therapeutic resistance and relapse of a variety of cancer types including hepatocellular carcinoma (HCC). However, the tracing of such a subpopulation in vivo has been challenging. We have previously demonstrated that the isoform 5 of the voltage-gated calcium channel α2δ1 subunit, which can be recognized specifically by a monoclonal antibody 1B50-1, is a bona fide surface marker for HCC stem cells. Here we developed a strategy for optical imaging of α2δ1-positive cells by using a fusion protein containing the single chain variable fragment (scFv) of Mab1B50-1 and the luciferase NanoLuc which was tagged with Flag in the C-terminal. The scFv of Mab1B50-1 was fused to the N-terminal of NanoLucFlag using overlap PCR, and the recombinant fragment, which was named as 1B50-1scFv-NanoLucFlag, was subsequently cloned into a eukaryotic expression vector. The resulting construct was transfected into FreeStyle 293F cells in suspension using PEI reagent. The expression of the fusion protein was identified as a protein with molecular weight about 50 kDa by Western blotting. After purification by ANTI-FLAG® M2 affinity chromatography, 1B50-1scFv-NanoLucFlag was demonstrated to bind to α2δ1 positive cells specifically with a Kd value of (18.62±1.84) nmol/L. Furthermore, a strong luciferase activity of 1B50-1scFv-NanoLucFlag was detected in α2δ1 positive cells following incubation with the fusion protein, indicating that the presence of α2δ1 could be quantified using this fusion protein. Hence, 1B50-1scFv-NanoLucFlag provides a potential tool for optical imaging of α2δ1 positive cancer stem cells both in vitro and in vivo.

Interferon-gamma inhibits aldehyde dehydrogenasebright cancer stem cells in the 4T1 mouse model of breast cancer / 中华医学杂志(英文版)

BACKGROUND@#Despite improvements in disease diagnosis, treatment, and prognosis, breast cancer is still a leading cause of cancer death for women. Compelling evidence suggests that targeting cancer stem cells (CSCs) have a crucial impact on overcoming the current shortcomings of chemotherapy and radiotherapy. In the present study, we aimed to study the effects of T cells and a critical anti-tumor cytokine, interferon-gamma (IFN-γ), on breast cancer stem cells.@*METHODS@#BALB/c mice and BALB/c nude mice were subcutaneously injected with 4T1 tumor cells. Tumor growth and pulmonary metastasis were assessed. ALDEFLOUR™ assays were performed to identify aldehyde dehydrogenasebright (ALDHbr) tumor cells. ALDHbr cells as well as T cells from tumor-bearing BALB/c mice were analyzed using flow cytometry. The effects of CD8+ T cells on ALDHbr tumor cells were assessed in vitro and in vivo. The expression profiles of ALDHbr and ALDHdim 4T1 tumor cells were determined. The levels of plasma IFN-γ were measured by enzyme-linked immunosorbent assay, and their associations with the percentages of ALDHbr tumor cells were evaluated. The effects of IFN-γ on ALDH expression and the malignancy of 4T1 tumor cells were analyzed in vitro.@*RESULTS@#There were fewer metastatic nodules in tumor-bearing BALB/c mice than those in tumor-bearing BALB/c nude mice (25.40 vs. 54.67, P < 0.050). CD8+ T cells decreased the percentages of ALDHbr 4T1 tumor cells in vitro (control vs. effector to target ratio of 1:1, 10.15% vs. 5.76%, P < 0.050) and in vivo (control vs. CD8+ T cell depletion, 10.15% vs. 21.75%, P < 0.001). The functions of upregulated genes in ALDHbr 4T1 tumor cells were enriched in the pathway of response to IFN-γ. The levels of plasma IFN-γ decreased gradually in tumor-bearing BALB/c mice, while the percentages of ALDHbr tumor cells in primary tumors increased. IFN-γ at a concentration of 26.68 ng/mL decreased the percentages of ALDHbr 4T1 tumor cells (22.88% vs. 9.88%, P < 0.050) and the protein levels of aldehyde dehydrogenase 1 family member A1 in 4T1 tumor cells (0.86 vs. 0.49, P < 0.050) and inhibited the abilities of sphere formation (sphere diameter <200 μm, 159.50 vs. 72.0; ≥200 μm, 127.0 vs. 59.0; both P < 0.050) and invasion (89.67 vs. 67.67, P < 0.001) of 4T1 tumor cells.@*CONCLUSION@#CD8+ T cells and IFN-γ decreased CSC numbers in a 4T1 mouse model of breast cancer. The application of IFN-γ may be a potential strategy for reducing CSCs in breast cancer.

The Predict Significance of ALDH Activity to the Relapse of t(8;21) Acute Myeloid Leukemia Patients at Complete Remission / 中国实验血液学杂志

OBJECTIVE@#To investigate the predict significance of the high aldehyde dehydrogenase activity (ALDH@*METHODS@#Bone marrow samples of 23 t(8;21) AML patients diagnosis and achieved complete remission in our hospital from April 2015 to June 2016 were collected, then flow cytometry method was used to detect the activity of ALDH, relationship between it and relapse was analyzed.@*RESULTS@#All the patients were followed up for a median of 32 (2-52) months. The median percentage of CD34@*CONCLUSION@#The percentage of CD34

Knocking down LSD1 inhibits the stemness features of colorectal cancer stem cells

As a top leading cause of cancer death in many countries, colorectal cancer (CRC) has drawn increasing attention to the study of the pathological mechanism. According to the "cancer stem cell hypothesis", malignancies originate from a small fraction of cancer cells that show self-renewal properties to initiate and sustain tumor growth and tumor metastasis. Therefore, these cancer stem cells (CSC) probably play important roles in tumor recurrence, metastasis, and drug resistance. Previous research reported that lysine-specific histone demethylase 1 (LSD1) maintains cancer stemness through up-regulating stemness markers SOX2 and OCT4. CD133 is believed to be the most robust surface marker for CRC stem cells, however the regulatory effect of LSD1 on stemness of CD133+ CRC has never been reported. In this study, our objectives included: 1) to isolate pure CD133+ and CD133− cells from SW620 cell line; 2) to investigate the effect of LSD1 on the characteristics of CD133+ stem cancer cells by knocking down the target gene. Results suggested that the SW620 cell line had both CD133+ and CD133− subsets. The CD133+ subset exhibited more CSC-like characteristics compared with the CD133− subset with higher viability, colony formation rate, migration and invasion rate, resistance to anti-cancer drugs, and apoptosis in vitro. The CD133+ also induced faster tumor formation and larger tumors in vivo. In the LSD1-knockdown CD133+ cells, the CSC-like characteristics had been all weakened. We conclude that LSD1 was important for CSCs to maintain their "stemness" features, which could be a potential therapeutic target of CRC.