A Pyroptosis-Related Gene Signature Predicts Prognosis and Tumor Immune Microenvironment in Colorectal Cancer.

Pyroptosis is a programmed cell death, which garners increasing attention by relating to immune and therapy response. However, the role of pyroptosis in colorectal cancer (CRC) remains unclear. Our study mainly to explore the role of pyroptosis in CRC. The mRNA expression data and corresponding clinical information of CRC patients were achieved from The Cancer Genome Atlas (TCGA). Pyroptosis-related genes (PRGs) were identified using DESeq2 R package and biological function was analyzed using cluster Profiler R package. A PRGs-based prognosis model was constructed by a univariate Cox and LASSO regression analyses. Then, the affecting of risk signature to clinicopathological characteristics, immune status and infiltrated immune cells, immune checkpoint and chemotherapy sensitivity was analyzed. qRT-PCR and IHC were performed for the expression level of PRGs. Moreover, a nomogram predict model was constructed. Total 57 PRGs were identified between 500 CRC samples and 44 normal samples. Those PRGs mainly enriched in immune-related and pyroptosis-related pathways. GABRD, NADK, TMEM240, RER1, AGRN, UBE2J2, CALML6, PLCH2, TMEM88B have been identified as gene signature and a prognostic model was constructed and validated. CRC patients with high-risk score showed poor survival, high TMB score, high proportion of CD4 + memory T cells, common lymphoid progenitors, cancer associated fibroblasts, mast cells, and neutrophils. The immune checkpoint related genes, CD160, CD200R1, CD244, CD28, CD40LG, CD44, CD48, CD80, CD86, HHLA2, ICOS, IDO1, TIGIT, TNFRSF25, TNFRSF4, TNFRSF9, TNFSF15, TNFSF18 also increased in high-risk score group. CRC patients with high-risk score more sensitive to docetaxel and rapamycin but resistance to gemcitabine and mitomycin. Moreover, a predictive nomogram for 1-, 3-, 5-year for CRC patients was established and validated. In the study, a PRGs-based prognostic model and a predictive model were constructed. These models are effective and robust in prediction the 1-, 3-, and 5-year survival of CRC patients.

Central and peripheral mechanisms underlying respiratory deficits in a mouse model of accelerated senescence.

Aging invariably decreases sensory and motor stimuli and affects several neuronal systems and their connectivity to key brain regions, including those involved in breathing. Nevertheless, further investigation is needed to fully comprehend the link between senescence and respiratory function. Here, we investigate whether a mouse model of accelerated senescence could develop central and peripheral respiratory abnormalities. Adult male Senescence Accelerated Mouse Prone 8 (SAMP8) and the control SAMR1 mice (10 months old) were used. Ventilatory parameters were assessed by whole-body plethysmography, and measurements of respiratory input impedance were performed. SAMP8 mice exhibited a reduction in the density of neurokinin-1 receptor immunoreactivity in the entire ventral respiratory column. Physiological experiments showed that SAMP8 mice exhibited a decreased tachypneic response to hypoxia (FiO2 = 0.08; 10 min) or hypercapnia (FiCO2 = 0.07; 10 min). Additionally, the ventilatory response to hypercapnia increased further due to higher tidal volume. Measurements of respiratory mechanics in SAMP8 mice showed decreased static compliance (Cstat), inspiratory capacity (IC), resistance (Rn), and elastance (H) at different ages (3, 6, and 10 months old). SAMP8 mice also have a decrease in contractile response to methacholine compared to SAMR1. In conclusion, our findings indicate that SAMP8 mice display a loss of the NK1-expressing neurons in the respiratory brainstem centers, along with impairments in both central and peripheral respiratory mechanisms. These observations suggest a potential impact on breathing in a senescence animal model.

CDC20 Holds Novel Regulation Mechanism in RPA1 during Different Stages of DNA Damage to Induce Radio-Chemoresistance.

Targeting CDC20 can enhance the radiosensitivity of tumor cells, but the function and mechanism of CDC20 on DNA damage repair response remains vague. To examine that issue, tumor cell lines, including KYSE200, KYSE450, and HCT116, were utilized to detect the expression, function, and underlying mechanism of CDC20 in radio-chemoresistance. Western blot and immunofluorescence staining were employed to confirm CDC20 expression and location, and radiation could upregulate the expression of CDC20 in the cell nucleus. The homologous recombination (HR) and non-homologous end joining (NHEJ) reporter gene systems were utilized to explore the impact of CDC20 on DNA damage repair, indicating that CDC20 could promote HR repair and radio/chemo-resistance. In the early stages of DNA damage, CDC20 stabilizes the RPA1 protein through protein-protein interactions, activating the ATR-mediated signaling cascade, thereby aiding in genomic repair. In the later stages, CDC20 assists in the subsequent steps of damage repair by the ubiquitin-mediated degradation of RPA1. CCK-8 and colony formation assay were used to detect the function of CDC20 in cell vitality and proliferation, and targeting CDC20 can exacerbate the increase in DNA damage levels caused by cisplatin or etoposide. A tumor xenograft model was conducted in BALB/c-nu/nu mice to confirm the function of CDC20 in vivo, confirming the in vitro results. In conclusion, this study provides further validation of the potential clinical significance of CDC20 as a strategy to overcome radio-chemoresistance via uncovering a novel role of CDC20 in regulating RPA1 during DNA damage repair.

MAPK Signaling-Mediated RFNG Phosphorylation and Nuclear Translocation Restrain Oxaliplatin-Induced Apoptosis and Ferroptosis.

Chemotherapy resistance remains a major challenge in the treatment of colorectal cancer (CRC). Therefore, it is crucial to develop novel strategies to sensitize cancer cells to chemotherapy. Here, the fringe family is screened to determine their contribution to chemotherapy resistance in CRC. It is found that RFNG depletion significantly sensitizes cancer cells to oxaliplatin treatment. Mechanistically, chemotherapy-activated MAPK signaling induces ERK to phosphorylate RFNG Ser255 residue. Phosphorylated RFNG S255 (pS255) interacts with the nuclear importin proteins KPNA1/importin-α1 and KPNB1/importin-ß1, leading to its translocation into the nucleus where it targets p53 and inhibits its phosphorylation by competitively inhibiting the binding of CHK2 to p53. Consequently, the expression of CDKN1A is decreased and that of SLC7A11 is increased, leading to the inhibition of apoptosis and ferroptosis. In contrast, phosphor-deficient RFNG S225A mutant showed increased apoptosis and ferroptosis, and exhibited a notable response to oxaliplatin chemotherapy both in vitro and in vivo. It is further revealed that patients with low RFNG pS255 exhibited significant sensitivity to oxaliplatin in a patient-derived xenograft (PDX) model. These findings highlight the crosstalk between the MAPK and p53 signaling pathways through RFNG, which mediates oxaliplatin resistance in CRC. Additionally, this study provides guidance for oxaliplatin treatment of CRC patients.

TRIM47 inhibits cisplatin chemosensitivity and endoplasmic reticulum stress-induced apoptosis of ovarian cancer cells.

Ovarian cancer (OC) is the fifth most common cause of death in women worldwide. Chemoresistance is a key reason for treatment failure, causing high mortality. As a member of the tripartite motif-containing (TRIM) protein family, tripartite motif 47 (TRIM47) plays a vital role in the carcinogenesis and drug resistance of various cancers. This study investigated the impact and mechanisms of TRIM47 on cisplatin (DDP) chemosensitivity and apoptosis in OC. OC cell viability was assessed with a cell counting kit-8 assay and OC cell apoptosis was assessed using flow cytometry, caspase-3 and caspase-9 activity, and Bax and Bcl-2 expression assays while gene and protein expression were assessed using qRT-PCR and Western blot assays. The expression of TRIM47 was significantly increased in both DDP-resistant tissues from patients with OC tissues and in cancer cell lines compared with that in normal tissue or parental cell lines. The increased level of TRIM47 correlated with poor prognosis in patients with OC. Functional assays demonstrated that TRIM47 promoted DDP resistance both in vitro and in vivo. The increased viability and reduced apoptosis of OC cells induced by TRIM47 can be rescued by the endoplasmic reticulum (ER) stress-inducer tunicamycin, suggesting that TRIM47 inhibits OC cell apoptosis by suppressing ER stress. Therefore, TRIM47 may be targeted as a therapeutic strategy for DDP resistance in OC.

Iron Overloading Potentiates the Antitumor Activity of 5-Fluorouracil by Promoting Apoptosis and Ferroptosis in Colorectal Cancer Cells.

Resistance to 5-fluorouracil (5-FU) remains a significant challenge in colorectal cancer (CRC) treatment. Ferric ammonium citrate (FAC) is commonly used as an iron supplement due to its food-fortification properties; however, its potential role as a chemosensitizer in cancer therapy has not been studied. In this study, we explored the ability of FAC to sensitize CRC cells and increase their susceptibility to 5-FU-mediated anticancer effects. We assessed cell viability, cell cycle progression, apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, ferroptosis, and iron metabolism-related protein expression using two CRC cell lines. Additionally, we conducted in silico analyses to compare iron markers in normal colon and CRC tumor tissues. Compared to controls, CRC cells pretreated with FAC and then treated with 5-FU exhibited significantly reduced growth and viability, along with increased ROS-mediated ferroptosis. Mechanistically, FAC-pretreated then 5-FU-treated CRC cells showed enhanced apoptosis, increased Bak/Bax expression, MMP depolarization, and decreased antiapoptotic protein levels (Bcl-2 and Bcl-xL). This combined treatment also led to G2/M cell cycle arrest, upregulation of p21 and p27, and downregulation of cyclin D1, c-Myc, survivin, and GPX4. Analysis of human colon tumor tissue revealed decreased expression of IRP-1, HMOX-1, and FTH1 but increased HAMP expression. In contrast, FAC-pretreated/5-FU-treated CRC cells exhibited a reverse pattern, suggesting that FAC-induced chemosensitization enhances 5-FU-mediated anticancer activity in CRC by disrupting iron homeostasis. These findings highlight the potential of iron overload as a chemosensitization strategy for improving CRC chemotherapy.

SIVA-1 interaction with PCBP1 serves as a predictive biomarker for cisplatin sensitivity in gastric cancer and its inhibitory effect on tumor growth in vivo.

Background: SIVA-1 has been reported to play a key role in cell apoptosis and gastric cancer (GC) chemoresistance in vitro. Nevertheless, the clinical significance of SIVA-1 in GC chemotherapy remains unclear. Methods and results: Immunohistochemistry and histoculture drug response assays were used to determine SIVA-1 expression and the inhibition rate (IR) of agents to GC and to further analyze the relationship between these two phenomena. Additionally, cisplatin (DDP)-resistant GC cells were used to elucidate the role and mechanism of SIVA-1 in vivo. The results demonstrated that SIVA-1 expression was positively correlated with the IR of DDP to GC but not with those of 5-fluorouracil (5-FU) or adriamycin (ADM). Furthermore, SIVA-1 overexpression with DDP treatment synergistically inhibited tumor growth in vivo by increasing PCBP1 and decreasing Bcl-2 and Bcl-xL expression. Conclusions: Our study demonstrated that SIVA-1 may serve as an indicator of the GC sensitivity to DDP, and the mechanism of SIVA-1 in GC resistance to DDP was preliminarily revealed.

Lysosomal cation channel TRPML1 suppression sensitizes acute myeloid leukemia cells to chemotherapeutics by inhibiting autophagy.

Despite the implementation of novel therapeutic regimens and extensive research efforts, chemoresistance remains a formidable challenge in the treatment of acute myeloid leukemia (AML). Notably, the involvement of lysosomes in chemoresistance has sparked interest in developing lysosome-targeted therapies to sensitize tumor cells to currently approved chemotherapy or as innovative pharmacological approaches. Moreover, as ion channels on the lysosomal membrane are critical regulators of lysosomal function, they present potential as novel targets for enhancing chemosensitivity. Here, we discovered that the expression of a lysosomal cation channel, namely transient receptor potential mucolipin 1 (TRPML1), was elevated in AML cells. Inhibiting TRPML1 individually does not impact the proliferation and apoptosis of AML cells. Importantly, inhibition of TRPML1 demonstrated the potential to modulate the sensitivity of AML cells to chemotherapeutic agents. Exploration of the underlying mechanisms revealed that suppression of TRPML1 impaired autophagy while concurrently increasing the production of reactive oxygen species (ROS) and ROS-mediated lipid peroxidation (Lipid-ROS) in AML cells. Finally, the knockdown of TRPML1 significantly reduced OCI-AML3 tumor growth following chemotherapy in a mouse model of human leukemia. In summary, targeting TRPML1 represents a promising approach for combination therapy aimed at enhancing chemosensitivity in treating AML.

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide.

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

MiR-200b-3p elevates 5-FU sensitivity in cholangiocarcinoma cells via autophagy inhibition by targeting KLF4.

Cholangiocarcinoma is one of the most lethal human cancers, and chemotherapy failure is a major cause of recurrence and poor prognosis. We previously demonstrated that miR-200 family members are downregulated in clinical samples of cholangiocarcinoma and inhibit cholangiocarcinoma tumorigenesis and metastasis. However, the role of differentially expressed miR-200b-3p in 5-fluorouracil chemosensitivity remains unclear. Here, we examined how miR-200b-3p modulates 5-fluorouracil chemosensitivity in cholangiocarcinoma. We observed that miR-200b-3p was associated with 5-fluorouracil sensitivity in cholangiocarcinoma and increased 5-fluorouracil-induced mitochondrial apoptosis in cholangiocarcinoma cells. Mechanistically, miR-200b-3p suppressed autophagy in cholangiocarcinoma cells to mediate 5-fluorouracil sensitivity. Further, we identified KLF4 as an essential target of miR-200b-3p in cholangiocarcinoma. Notably, the miR-200b-3p/KLF4/autophagy pathway augmented the chemosensitivity of cholangiocarcinoma cells to 5-fluorouracil. Our findings underscore the key role of miR-200b-3p in chemosensitivity to 5-fluorouracil and highlight the miR-200b-3p/KLF4/autophagy axis as a potential therapeutic target for cholangiocarcinoma.

NKILA is a novel suppressor of local recurrence in women breast malignant phyllodes tumor patients via inhibition of the NF-κB pathway.

The aim of the present study was to explore the functional mechanism of NF-Kappa B-interacting Long non-protein coding RNA (NKILA) in breast malignant phyllodes tumors (BMPTs). The expression and functional role of NKILA were investigated by performing qRT‒PCR, Transwell assays, and CCK‒8 assays in primary BMPT cells. A Kaplan‒Meier curve was used to assess overall survival (OS) and local recurrence-free survival (LRFS). The location and expression levels of NKILA and P65 were determined by fluorescence in situ hybridization (FISH) and immunofluorescence (IF), respectively. NKILA was downregulated in patients with BMPT, especially in patients with local recurrence. NKILA had an antitumor effect and promoted the chemosensitivity of cells to cisplatin by blocking P65 phosphorylation and nuclear translocation. In conclusion, NKILA may be a potential therapeutic target for BMPT, especially for BMPT patients with local recurrence.

Long-term effects on cardiorespiratory and behavioral responses in male and female rats prenatally exposed to cannabinoid.

Development of the respiratory system can be affected by the use of drugs during pregnancy, as the prenatal phase is highly sensitive to pharmacological interventions, resulting in long-term consequences. The deleterious effects of external cannabinoids during gestation may be related to negative interference in central nervous system formation, cardiorespiratory system function, and behavioral disorders. Nevertheless, the impact of external cannabinoids on cardiorespiratory network development, chemosensitivity, and its future consequences in adulthood is still unclear. We evaluated the effects of prenatal exposure to a synthetic cannabinoid (WIN 55,212-2, 0.5 mg.kg-1.day-1) on the cardiorespiratory control and panic-like behavior of male and female rats in adulthood. Exogenous cannabinoid exposure during pregnancy resulted in a sex-dependent difference in breathing control. Specifically, males showed increased chemosensitivity to CO2 and O2, while females exhibited decreased sensitivity. Altered cardiovascular control was evident, with prenatally treated males and females being more susceptible to hypertension and tachycardia under adverse environmental conditions. Moreover, WIN-treated males exhibited higher fragmentation of sleep episodes, while females displayed anxiolytic and panicolytic behavioral responses to CO2. However, no changes were observed in the mechanical component of the respiratory system, and there were no neuroanatomical alterations, such as changes in the expression of CB1 receptors in the brainstem or in the quantification of catecholaminergic and serotonergic neurons. These findings highlight that external interference in cannabinoid signaling during fetal development causes sex-specific long-lasting effects for the cardiorespiratory system and behavioral responses in adulthood.

Tanshinone I improves TNBC chemosensitivity by suppressing late-phase autophagy through AKT/p38 MAPK signaling pathway.

The inhibition of autophagy is a potential therapeutic strategy to improve the chemosensitivity of triple-negative breast cancer (TNBC). In this study, we demonstrated that a natural terpenoid tanshinone I (TAN) enhanced the effectiveness of paclitaxel (PTX), at least in part, through an autophagy-dependent mechanism against TNBC. In vitro validation demonstrated that the combined therapy resulted in a synergistic decrease in the growth of TNBC cells. The chemosensitizing impact of TAN might be attributed to its inhibition of PTX-induced autophagy in the late phase by obstructing the fusion of autophagosomes and lysosomes, rather than by inhibiting lysosomal function. The findings from KEGG pathway analysis and molecular docking suggested that TAN might impact breast cancer chemoresistance primarily through the PI3K-Akt and MAPK signaling pathways. The non-canonical AKT/p38 MAPK signaling was further validated as the primary mechanism responsible for the inhibition of autophagy by TAN. In vivo study showed that the combined administration of TAN and PTX demonstrated a more significant suppression of tumor growth and autophagic activity compared to PTX monotherapy in the MDA-MB-231 xenograft nude mouse model. The safety evaluation of TAN in a zebrafish model, along with in vitro and in vivo validation, provided experimental and pre-clinical data supporting its potential as a natural adjunctive therapy in TNBC. Overall, this study suggests that the combination of TAN with PTX could provide an effective treatment option for advanced breast cancer, and targeting the AKT/p38 MAPK/late-autophagy signaling axis may be a promising approach for developing therapeutic interventions against TNBC.

PFKL promotes cell viability and glycolysis and inhibits cisplatin chemosensitivity of laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) with a high incidence and mortality rate, has a serious impact worldwide. Phosphofructokinase-1 liver type (PFKL) is a major enzyme in glycolysis progress, but its role in modulating tumorigenesis and cisplatin (DDP) chemosensitivity of LSCC was still unclear. The mRNA and protein levels of PFKL were detected by qRT-PCR and immunohistochemical assay. Cell Counting Kit-8 assay and flow cytometry were carried out to observe cell viability, as well as apoptosis and mitochondrial reactive oxygen species (mito-ROS). Extracellular acidification rate and lactate content were measured using extracellular flux analysis and lactate assay kit. Immunofluorescent staining was used to evaluate the expression of γ-H2AX foci. DNA damage was detected via single-cell gel electrophoresis. Western blotting was introduced to evaluate the protein level of PFKL, LDHA, γ-H2AX, cleaved PARP, H3K27ac, and H3K9ac. Mice xenograft model of LSCC was built for in vivo validation. The PFKL expression was significantly increased in LSCC and associated with poor survival of LSCC patients. Knockdown of PFKL in LSCC cells significantly inhibited cell viability, ECAR, lactate content, and LDHA expression, but promoted mito-ROS level. Furthermore, knockdown of PFKL enhanced response of LSCC cells to DDP by increasing DDP-induced apoptosis, promoting DDP-induced mito-ROS level, γ-H2AX foci, tail DNA, and the expression of γ-H2AX and cleaved PARP. However, the overexpression of PFKL in LSCC cells had opposite experimental results. Nude mice tumor formation experiment proved that downregulation of PFKL significantly enhanced response of cells to DDP, demonstrated by reduced tumor volume, weight and increased TUNEL-positive cells. Suppression of CBP/EP300-mediated PFKL transcription inhibited cell viability and glycolysis and promoted mito-ROS in LSCC. PFKL promotes cell viability and DNA damage repair in DDP-treated LSCC through regulation of glycolysis pathway.

Discovery, identification and mechanism of chemosensitivity-relate biomarker inter-α-trypsin inhibitor heavy chain 4 in metastatic colorectal cancer.

Predictive biomarkers of response to chemotherapy in patients with metastatic colorectal cancer (mCRC) are needed to better characterize tumors and enable more tailored therapies. Here we used serum proteomics to screen for chemotherapy predictive markers. We found that higher baseline serum inter-α-trypsin inhibitor Heavy Chain 4 (ITIH4) expression in newly diagnosed mCRC patients was associated with poorer response to standard first-line chemotherapy. In addition, the higher expression of ITIH4 in CRC tissue also suggested poorer prognosis mCRC patients. Moreover, the overexpression of ITIH4 could promote the proliferation of CRC cells and reduce the sensitivity of CRC cells to 5-fluorouracil (5-FU) by inhibiting apoptosis in vivo and vitro. Through RNA-seq combined with bioinformatics analysis, we speculated that ITIH4 may activate phosphatidyl 3-kinase-protein kinase B (PI3K-AKT) pathway to inhibit apoptosis, thereby reducing the sensitivity of CRC cells to 5-FU. In conclusion, our findings unveil that ITIH4 is associated with CRC resistance to 5-FU, and may serve as a potential predictive biomarker for the sensitivity of advanced CRC patients to standard first-line chemotherapy regimens, and also provide a potential therapeutic target to render 5-FU resistance in CRC patients.

QPH-FR: A Novel Quinoa Peptide Enhances Chemosensitivity by Targeting Leucine-Rich Repeat-Containing G Protein-Coupled Receptor 5 in Colorectal Cancer.

Chemoresistance is one of the difficulties in the treatment of colorectal cancer (CRC), and the enhanced stemness of tumor cells is the underlying contributing factor. Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) is a classical marker of CRC stem cells and can be an important potential target for CRC chemotherapy. Quinoa, a protein-rich plant, offers potential as a source of high-quality active peptides. Novelly, the study obtained quinoa protein hydrolysate (QPH) from whole quinoa grains by simulated digestion. In vivo experiments revealed that the tumor volume in the 5-FU+QPH group decreased from 145.90 ± 13.35 to 94.49 ± 13.05 mm3 in the 5-FU group, suggesting that QPH enhances the chemosensitivity of CRC. Further, the most effective peptide QPH-FR from 631 peptides in QPH was screened by activity prediction, molecular docking, and experimental validation. Mechanistically, QPH-FR competitively suppressed the formation of the LGR5/RSPO1 complex by binding to LGR5, causing RNF43/ZNRF3 to ubiquitinate the FZD receptor, thereby suppressing the Wnt/ß-catenin signaling pathway and exerting stemness inhibition. In summary, the study proposes that a novel peptide QPH-FR from quinoa elucidates the mechanism by which QPH-FR targets LGR5 to enhance chemosensitivity, providing theoretical support for the development of chemotherapeutic adjuvant drugs based on plant peptides.

Luteolin enhances drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in paclitaxel­resistant esophageal squamous cell carcinoma.

Drug resistance is a key factor underlying the failure of tumor chemotherapy. It enhances the stem­like cell properties of cancer cells, tumor metastasis and relapse. Luteolin is a natural flavonoid with strong anti­tumor effects. However, the mechanism(s) by which luteolin protects against paclitaxel (PTX)­resistant cancer cell remains to be elucidated. The inhibitory effect of luteolin on the proliferation of EC1/PTX and EC1 cells was detected by cell counting kit­8 assay. Colony formation and flow cytometry assays were used to assess clonogenic capacity, cell cycle and apoptosis. Wound healing and Transwell invasion tests were used to investigate the effects of luteolin on the migration and invasion of EC1/PTX cells. Western blotting was used to detect the protein levels of EMT­related proteins and stem cell markers after sphere formation. Parental cells and drug­resistant cells were screened by high­throughput sequencing to detect the differential expression of RNA and differential genes. ELISA and western blotting were used to verify the screened PI3K/Akt signaling pathway, key proteins of which were explored by molecular docking. Hematoxylin and eosin staining and TUNEL staining were used to observe tumor xenografts on morphology and apoptosis in nude mice. The present study found that luteolin inhibited tumor resistance (inhibited proliferation, induced cell cycle arrest and apoptosis and hindered migration invasion, EMT and stem cell spherification) in vitro in PTX­resistant esophageal squamous cell carcinoma (ESCC) cells. In addition, luteolin enhanced drug sensitivity and promoted the apoptosis of drug­resistant ESCC cells in combination with PTX. Mechanistically, luteolin may inhibit the PI3K/AKT signaling pathway by binding to the active sites of focal adhesion kinase (FAK), Src and AKT. Notably, luteolin lowered the tumorigenic potential of PTX­resistant ESCC cells but did not show significant toxicity in vivo. Luteolin enhanced drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in PTX­resistant ESCC and could be a promising agent for the treatment of PTX­resistant ESCC cancers.

Role of HIF-1α in the Responses of Tumors to Radiotherapy and Chemotherapy.

Tumor microenvironment is intrinsically hypoxic with abundant hypoxia-inducible factors-1α (HIF-1α), a primary regulator of the cellular response to hypoxia and various stresses imposed on the tumor cells. HIF-1α increases radioresistance and chemoresistance by reducing DNA damage, increasing repair of DNA damage, enhancing glycolysis that increases antioxidant capacity of tumors cells, and promoting angiogenesis. In addition, HIF-1α markedly enhances drug efflux, leading to multidrug resistance. Radiotherapy and certain chemotherapy drugs evoke profound anti-tumor immunity by inducing immunologic cell death that release tumor associated antigens together with numerous pro-immunological factors, leading to priming of cytotoxic CD8+ T cells and enhancing the cytotoxicity of macrophages and NK cells. Radiotherapy and chemotherapy of tumors significantly increase HIF-1α activity in tumor cells. Unfortunately, HIF-1α effectively promotes various immune suppressive pathways including secretion of immune suppressive cytokines, activation of myeloid-derived suppressor cells (MIDSCs), activation of regulatory T cells (Tregs), inhibition of T cells priming and activity, and upregulation of immune checkpoints. Consequently, the anti-tumor immunity elevated by radiotherapy and chemotherapy is counterbalanced or masked by the potent immune suppression promoted by HIF-1α. Effective inhibition of HIF-1α may significantly increase the efficacy of radiotherapy and chemotherapy by increasing radiosensitivity and chemosensitivity of tumor cells and also by upregulating anti-tumor immunity.

Sialic Acids Blockade-Based Chemo-Immunotherapy Featuring Cancer Cell Chemosensitivity and Antitumor Immune Response Synergies.

Immune checkpoint blockade (ICB) has significantly improved the prognosis of patients with cancer, although the majority of such patients achieve low response rates; consequently, new therapeutic approaches are urgently needed. The upregulation of sialic acid-containing glycans is a common characteristic of cancer-related glycosylation, which drives disease progression and immune escape via numerous pathways. Herein, the development of self-assembled core-shell nanoscale coordination polymer nanoparticles loaded with a sialyltransferase inhibitor, referred to as NCP-STI which effectively stripped diverse sialoglycans from cancer cells, providing an antibody-independent pattern to disrupt the emerging Siglec-sialic acid glyco-immune checkpoint is reported. Furthermore, NCP-STI inhibits sialylation of the concentrated nucleoside transporter 1 (CNT1), promotes the intracellular accumulation of anticancer agent gemcitabine (Gem), and enhances Gem-induced immunogenic cell death (ICD). As a result, the combination of NCP-STI and Gem (NCP-STI/Gem) evokes a robust antitumor immune response and exhibits superior efficacy in restraining the growth of multiple murine tumors and pulmonary metastasis. Collectively, the findings demonstrate a novel form of small molecule-based chemo-immunotherapy approach which features sialic acids blockade that enables cooperative effects of cancer cell chemosensitivity and antitumor immune responses for cancer treatment.

KIN17 functions in DNA damage repair and chemosensitivity by modulating RAD51 in hepatocellular carcinoma.

The limited response of hepatocellular carcinoma (HCC) to chemotherapy drugs has always been a bottleneck in therapy. DNA damage repair is a major reason for chemoresistance. Previous studies have confirmed that KIN17 affects chemosensitivity. In this study, we examined the impact of KIN17 on chemotherapy response and DNA repair in HCC cells treated with oxaliplatin (L-OHP). We evaluated the expression and biological roles of KIN17 in HCC using bioinformatic analysis. The correlation between KIN17 and RAD51, particularly their nuclear expression levels, was evaluated using immunofluorescence, immunoblotting after nucleocytoplasmic separation in HCC cells, and immunohistochemistry of mouse xenograft tumors and human HCC tissues. The results indicated a significant increase in KIN17 expression in HCC tissues compared to normal tissues. The GSEA analysis revealed that upregulation of KIN17 was significantly associated with DNA damage repair. Knockdown of KIN17 led to increased DNA damage and reduced cellular survival after exposure to L-OHP. On the other hand, overexpression of KIN17 was linked to decreased DNA damage and improved cell survival following L-OHP treatment. Further experiments indicated that KIN17 affects the expression of RAD51, particularly in the nucleus. KIN17 plays a crucial role in influencing the sensitivity of HCC to chemotherapy by triggering the DNA repair response. Increased expression of KIN17 is associated with a poor prognosis for HCC patients, indicating that KIN17 could serve as a prognostic marker and therapeutic target for HCC.