IL-6/STAT3 signaling pathway induces prostate apoptosis response protein-4(PAR-4) to stimulate malignant behaviors of hepatocellular carcinoma cells.

INTRODUCTION AND OBJECTIVES: Prostate apoptosis response protein-4 (PAR-4) is considered a tumor suppressor. However, the role of PAR-4 in hepatocellular carcinoma (HCC) has rarely been reported. The study explores the role of PAR-4 in the malignant behaviors of HCC cells. MATERIALS AND METHODS: TCGA database was applied to analyze the expression of PAR-4 in HCC. Evaluated PAR-4 relationship with clinical parameters and prognosis by tissue microarray; expression of STAT3, p-STAT3, Src and Ras was detected by Western blotting or laser confocal microscopy. Cell scratch and flow cytometry assays were used to observe IL-6 regulation of the malignant behaviors of HCC cells. The tumorigenic potential of HCC cells in vivo was evaluated in a nude mouse tumor model. RESULTS: Analysis indicated that the expression of PAR-4 in HCC tissues was significantly higher than that in normal liver tissues; and PAR-4 interacted with STAT3. KEGG analysis showed that PAR-4 plays a role in the Janus kinase (JAK)/STAT signaling pathway. The positive expression rate of PAR-4 in HCC tissues was significantly higher than that in adjacent tissues. Positive correlation between IL-6 and PAR-4 expression in the HCC tissues. Exogenous IL-6 significantly promoted the proliferation and migration of HCC cells and up-regulated the expression of PAR-4 and p-STAT3 in HCC cells. Interference of the expression of PAR-4 could reduce the malignant behaviors of HCC cells and inhibit tumorigenesis in a nude mouse tumor model. CONCLUSIONS: PAR-4 expression is positively correlated with HCC; PAR-4 promotes malignant behavior of HCC cells mediated by the IL-6/STAT3 signaling pathway.

Effect and mechanism of resveratrol on ferroptosis mediated by p53/SLC7A11 in oral squamous cell carcinoma.

OBJECTIVE: Resveratrol (Res) is a natural phytoestrogen with antitumor activity. This study sought to investigate the role of Res in ferroptosis in oral squamous cell carcinoma (OSCC). METHODS: Normal human oral keratinocyte (HOK)/oral OSCC (CAL-27/SCC-9) cell lines were treated with different doses of Res. Res toxicity was determined by MTT assay, with half maximal inhibitory concentration values of Res on CAL-27 and SCC-9 cells calculated. Cell viability/colony formation efficiency/migration/invasion/cycle were assessed by CCK-8/colony formation assay/transwell assay/flow cytometry. The expression of p53 protein in the nucleus and cytoplasm, glutathione peroxidase 4 (GPX4) expression, and SLC7A11 messenger RNA (mRNA) and protein expression levels were determined by Western blot and RT-qPCR. Fe2+ content, reactive oxygen species (ROS) level, reduced glutathione (GSH), and lactate dehydrogenase (LDH) release were assessed. RESULTS: Medium- to low-dose Res had no toxic effect on HOK cells, while high-dose Res markedly reduced HOK cell viability. Res significantly suppressed the viability of OSCC cells (CAL-27 and SCC-9). Res inhibited OSCC cell colony formation/migration/invasion, and induced G1 phase arrest. Res caused the translocation of p53 protein to the nucleus, obviously increased Fe2+ content, ROS level and LDH release, decreased GSH content and GPX4 protein expression, and induced ferroptosis. Down-regulation of p53 partially reversed the inhibitory effects of Res on CAL-27 cell malignant behaviors. Res inhibited SLC7A11 transcription by promoting p53 entry into the nucleus. SLC7A11 overexpression negated the the regulatory effects of p53 knockout on the role of Res in OSCC cell malignant behaviors and ferroptosis. CONCLUSION: Res accelerated ferroptosis and inhibited malignant behaviors in OSCC cells by regulating p53/SLC7A11.

CUL4B enhances the malignant phenotype of esophageal squamous cell carcinoma by suppressing TGFBR3 expression.

Cullin 4B (CUL4B), which acts as a scaffold protein in CUL4B-RING ubiquitin ligase complexes (CRL4B), is frequently overexpressed in cancer and represses tumor suppressors through epigenetic mechanisms. However, the expression and function of CUL4B in esophageal squamous cell carcinoma (ESCC) have not been well illustrated. In this study, we show that upregulation of CUL4B in ESCC cells enhances proliferation, invasion and cisplatin (CDDP)-resistance, while knockdown of CUL4B significantly represses the malignant activities. Mechanistically, we demonstrate that CUL4B promotes proliferation and migration of ESCC cells through inhibiting expression of transforming growth factor beta receptor III (TGFBR3). CRL4B complex binds to the promoter of TGFBR3, and represses its transcription by catalyzing monoubiquitination at H2AK119 and coordinating with PRC2 and HDAC complexes. Taken together, our findings establish a critical role for the CUL4B/TGFBR3 axis in the regulation of ESCC malignancy.

circ_0044516 functions in the progression of gastric cancer by modulating MicroRNA-149-5p/HuR axis.

Circular RNAs (circRNAs) have emerged as a multifunctional class of RNAs, while there is limited knowledge on their functions in the development of cancers. Herein, we performed the current study to probe into the regulatory mechanism of circ_0044516 in malignant behaviors of gastric cancer (GC) cells with the involvement of microRNA (miR)-149-5p/human antigen R (HuR) axis. Firstly, the expression levels of circ_0044516 in GC cell lines and normal gastric mucosal epithelial cells were determined by qRT-PCR, and GC cell lines with the highest expression of circ_0044516 were screened for further cell experiments. Subsequently, the biological functions of silenced circ_0044516 in GC were identified by CCK-8, colony formation, and transwell assays. Xenograft mouse models were established for in vivo verification. Furthermore, luciferase reporter, RIP, RNA pull-down assay and rescue experiments were performed to explore the sponge regulatory mechanism of circ_0044516. circ_0044516 was suggested to be highly expressed in GC cell lines, and circ_0044516 could promote GC cell proliferation, migration and invasion, as well as in vivo tumor growth. In addition, silenced circ-0044516 reversed the promotive roles in cell viability caused by overexpressed HuR. Furthermore, circ_0044516 mainly localized in the cytoplasm, which may act as a miR-149-5p sponge to modulate HuR expression, thereby playing an essential role in GC development. This study suggests that circ_0044516 may promote HuR expression through sponging miR-149-5p, thereby playing a part in GC progression.

Long non-coding RNA LINC01116 is activated by EGR1 and facilitates lung adenocarcinoma oncogenicity via targeting miR-744-5p/CDCA4 axis.

BACKGROUND: Lung adenocarcinoma (LAD) is one of the most frequently diagnosed pathological categories of human lung cancer. Nevertheless, the link between long non-coding RNA (lncRNA) LINC01116 and LAD remains poorly investigated. METHODS: QRT-PCR and western blot were applied for quantifying the expression of RNAs and proteins. Both functional experiments assays in vitro and xenografts model in vivo were implemented for analyzing LINC01116 function in LAD while molecular relationship among RNAs was investigated via mechanism experiments. RESULTS: LINC01116 was expressed at an abnormally high level in LAD, which was induced by transcription activator EGR1. LINC01116 depletion restrained proliferation, migration and invasion, yet facilitated apoptosis of LAD cells. MiR-744-5p could bind to LINC01116. MiR-744-5p inhibitor reversed the inhibitory effects of silencing LINC01116 on LAD malignant behaviors. In addition, cell division cycle-associated protein 4 (CDCA4) shared binding sites with miR-744-5p. Silencing LINC01116 elicited decline in CDCA4 mRNA and protein levels. Moreover, CDCA4 up-regulation could counteract the biological effects of LINC01116 knockdown on LAD cells. CONCLUSION: Our data revealed that LINC01116 promoted malignant behaviors of LAD cells by targeting miR-744-5p/CDCA4 axis, implying the theoretical potential of LINC01116 as a novel target for LAD treatment.

Silencing of long non-coding RNA CCAT2 depressed malignancy of oral squamous cell carcinoma via Wnt/ß-catenin pathway.

Oral squamous cell carcinoma is a common and lethal malignancy affecting the head and neck region. CCAT2 (colon cancer-associated transcript 2) gene is affiliated with long non-coding RNAs, which are often found to have important regulatory roles in cancers. This study aims to assess the expression and clinical significance of CCAT2 gene, identify its malignant biological behaviors, and explore the possible mechanisms in oral squamous cell carcinoma. CCAT2 expression was detected by quantitative real-time polymerase chain reaction, and its relationship with clinical factors was assayed using the Kaplan-Meier survival curve. The biological behaviors of CCAT2 and its potential mechanisms in oral squamous cell carcinoma were explored by the combined use of CCAT2 knockdown technology and the Wnt/ß-catenin pathway agonist lithium chloride (LiCl). Our results showed that CCAT2 functioning as a potential oncogene was upregulated in oral squamous cell carcinoma. CCAT2 with high expression level was correlated with poor differentiation, higher T stage, and clinical stage, which made CCAT2 to be a prognostic biomarker in oral squamous cell carcinoma. LiCl-activated Wnt/ß-catenin signaling pathway could partly restore the CCAT2-mediated malignant biological behaviors of oral squamous cell carcinoma cells by suppressing ß-catenin, CCND1, and MYC and activating glycogen synthase kinase 3 beta expression. These findings might assist in the discovery of novel potential diagnostic and therapeutic target for oral squamous cell carcinoma, thereby improve the effects of clinical treatment in patients.

miR-155-5p modulates malignant behaviors of hepatocellular carcinoma by directly targeting CTHRC1 and indirectly regulating GSK-3ß-involved Wnt/ß-catenin signaling.

BACKGROUND: Hepatocellular carcinoma (HCC) remains one of the most lethal cancers. MicroRNA-155 (miR-155) and collagen triple helix repeat containing 1 (CTHRC1) were found to be involved in hepatocarcinogenesis, but their detailed functions in HCC are unclear. Here, we aimed to investigate the underlying role of miR-155-5p and CTHRC1 in HCC. METHODS: miR-155-5p and CTHRC1 expression levels were detected by qRT-PCR, IHC and WB in HCC patients and cell lines. Dual-luciferase assay, qRT-PCR and WB were used to validate the target interaction between miR-155-5p and CTHRC1. Biological behaviors, including apoptosis, cell cycle progression, and cell proliferation, invasion and migration, were measured by flow cytometry, CCK-8 assay and Transwell tests. A xenograft model was established to examine the effects of miR-155-5p and CTHRC1 on tumor formation. WB was finally utilized to identify the role of GSK-3ß-involved Wnt/ß-catenin signaling in HCC growth and metastasis. RESULTS: Our results showed that miR-155-5p and CTHRC1 were down-regulated and up-regulated, respectively, in HCC patients and cell lines. Dual-luciferase assay verified that CTHRC1 was the direct target of miR-155-5p. Moreover, elevated miR-155-5p expression promoted apoptosis but suppressed cell cycle progression and cell proliferation, invasion and migration in vitro and facilitated tumor formation in vivo; elevated CTHRC1 expression abolished these biological effects. Additionally, miR-155-5p overexpression increased metastasis- and anti-apoptosis-related protein expression and decreased pro-apoptosis-related protein expression, while forced CTHRC1 expression conserved the expression of these proteins. CONCLUSION: Altogether, our data suggested that miR-155-5p modulated the malignant behaviors of HCC by targeting CTHRC1 and regulating GSK-3ß-involved Wnt/ß-catenin signaling; thereby, miR-155-5p and CTHRC1 might be promising therapeutic targets for HCC patients.

Increase in IkappaB kinase alpha expression suppresses the tumor progression and improves the prognosis for nasopharyngeal carcinoma.

Recent studies have suggested that the action of IkappaB kinase alpha (IKKα) as a tumor suppressor is crucial in the development of skin carcinoma, but its role in nasopharyngeal carcinoma (NPC) remains unknown. We examined the IKKα expression in specimens from 157 NPC patients by immunohistochemistry and analyzed the effect of IKKα on prognosis. The functional significance of IKKα expression in NPC cell lines was investigated by IKKα overexpression or downregulation in in vitro studies. The in vitro assays revealed that the IKKα expression was negatively correlated with the invasiveness, migration, and angiogenesis of NPC cells. Overexpression or downregulation of IKKα could significantly repress or enhance the above characteristics, respectively, and these effects were independent of IKKα kinase or EBNA1. In 157 NPC cases, IKKα was differentially expressed in NPC tissues. High expression of IKKα was associated significantly with a high disease-free survival (DFS; P = 0.002) or overall survival (OS; P = 0.014). Multivariate analyses showed that the IKKα expression was an independent risk factor for DFS (HR, 2.302; P = 0.011) and OS (HR, 3.578; P = 0.006). Our findings indicated that IKKα plays a crucial role as a tumor suppressor that suppresses the invasion, metastasis, and angiogenesis of NPC cells in vitro and correlates with the survival in NPC patients. Therefore, IKKα is not only a novel independent prognostic indicator in NPC, but also targeting IKKα expression may provide a potential therapeutic strategy for NPC.

The role of transcription factors in the crosstalk between cancer-associated fibroblasts and tumor cells.

BACKGROUND: Transcription factors (TFs) fulfill a critical role in the formation and maintenance of different cell types during the developmental process as well as disease. It is believed that cancer-associated fibroblasts (CAFs) are activation status of tissue-resident fibroblasts or derived from form other cell types via transdifferentiation or dedifferentiation. Despite a subgroup of CAFs exhibit anti-cancer effects, most of them are reported to exert effects on tumor progression, further indicating their heterogeneous origin. AIM OF REVIEW: This review aimed to summarize and review the roles of TFs in the reciprocal crosstalk between CAFs and tumor cells, discuss the emerging mechanisms, and their roles in cell-fate decision, cellular reprogramming and advancing our understanding of the gene regulatory networks over the period of cancer initiation and progression. KEY SCIENTIFIC CONCEPTS OF REVIEW: This manuscript delves into the key contributory factors of TFs that are involved in activating CAFs and maintaining their unique states. Additionally, it explores how TFs play a pivotal and multifaceted role in the reciprocal crosstalk between CAFs and tumor cells. This includes their involvement in processes such as epithelial-mesenchymal transition (EMT), proliferation, invasion, and metastasis, as well as metabolic reprogramming. TFs also have a role in constructing an immunosuppressive microenvironment, inducing resistance to radiation and chemotherapy, facilitating angiogenesis, and even 'educating' CAFs to support the malignancies of tumor cells. Furthermore, this manuscript delves into the current status of TF-targeted therapy and considers the future directions of TFs in conjunction with anti-CAFs therapies to address the challenges in clinical cancer treatment.

[Kuwanon G inhibits growth, migration and invasion of gastric cancer cells by regulating the PI3K/AKT/mTOR pathway].

OBJECTIVE: To investigate the effects of kuwanon G (KG) on proliferation, apoptosis, migration and invasion of gastric cancer cells and the molecular mechanisms. METHODS: The effects of KG on proliferation and growth of gastric cancer cells were assessed with CCK-8 assay and cell clone formation assay, by observing tumor formation on the back of nude mice and using immunohistochemical analysis of Ki-67. The effect of KG on cell apoptosis was analyzed using Annexin V-FITC/PI apoptosis detection kit, Western blotting and TUNEL staining. The effects of KG on cell migration and invasion were detected using Transwell migration and invasion assay and Western blotting for matrix metalloproteinase (MMP). The role of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in KG-mediated regulation of gastric cancer cell proliferation, migration, and invasion was verified by Western blotting and rescue assay. RESULTS: KG significantly inhibited proliferation and reduced clone formation ability of gastric cancer cells in a concentration-dependent manner (P < 0.05). KG treatment also increased apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, down-regulated Bcl-2, lowered migration and invasion capacities and inhibited the expression of MMP2 and MMP9 in gastric cancer cells (P < 0.05). Mechanistic validation showed that KG inhibited the activation of the PI3K/AKT/mTOR pathway, and IGF-1, an activator of the PI3K/AKT/mTOR pathway, reversed the effects of KG on proliferation, migration and invasion of gastric cancer cells (P < 0.05). CONCLUSION: KG inhibits proliferation, migration and invasion and promotes apoptosis of gastric cancer cells at least in part by inhibiting the activation of the PI3K/AKT/mTOR pathway.

FOXO3 suppresses lymphoma progression through promoting miR-34b/HSPG2 axis.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, which caused many patients to lose their precious lives. FOXO3 was a suppressor in various cancers, however, the role and mechanism of FOXO3 in DLBCL remain unclear. METHODS: Bioinformatics analysis was used to offer information FOXO3 expression and its expression for prognosis of DLBCL patients. The abundance of genes and proteins was evaluated using RT-qPCR and western blot. Cell proliferation and apoptosis was detected by CCK-8 and flow cytometry. The interactions among FOXO3, miR-34b, and HSPG2 were predicted by TransmiR and Starbase and validated using dual luciferase reporter assay, ChIP assay, and RIP assay. RESULTS: Our findings revealed that FOXO3 expression was abnormally declined in DLBCL cells. FOXO3 upregulation restrained cell proliferation and promoted cell apoptosis of DLBCL cells, while miR-34b inhibitor eliminated these influences. Similarly, miR-34b mimic suppressed malignant behaviors of DLBCL cells, which were abolished by HSPG2 overexpression. Mechanically, FOXO3 induced miR-34b expression through interacting with miR-34b promoter and HSPG2 was a targeted gene of miR-34b. CONCLUSION: FOXO3 attenuated the capability of cell proliferation and promoted cell apoptosis rate of DLBCL cells through affecting miR-34b/HSPG2 axis, therefore inhibiting DLBCL progression.

eIf3a mediates malignant biological behaviors in colorectal cancer through the PI3K/AKT signaling pathway.

Colorectal cancer (CRC) is among the most common gastrointestinal malignancies worldwide. eIF3a is highly expressed in a variety of cancer types, yet its role in CRC remains unclear. We introduced ectopic eIF3a expression in CRC cells to investigate its relevance to various malignant behaviors. Further, we silenced eIF3a to explore its effect on tumor growth in a nude mouse tumor xenograft model. Finally, the molecular mechanisms through which eIF3a regulates malignancy in CRC cells were explored through bioinformatics analysis combined with the use of a specific PI3K inhibitor (LY294002). eIF3a was highly expressed in the peripheral blood and cancer tissue of CRC patients. Malignancy and tumor growth were significantly inhibited by silencing eIF3a, while overexpression promoted malignant behaviors, with a positive correlation between PI3K/AKT activation and eIF3a expression. Taken together, eIF3a plays an oncogenic role in CRC by regulating PI3K/AKT signaling and is a potential biomarker for CRC diagnosis and prognostic monitoring.

Chaperonin containing TCP1 subunit 6A may activate Notch and Wnt pathways to facilitate the malignant behaviors and cancer stemness in oral squamous cell carcinoma.

Chaperonin containing TCP1 subunit 6A (CCT6A) was recently discovered to be involved in cancer pathogenesis and stemness; however, its role in oral squamous cell carcinoma (OSCC) has not been reported. The current study aimed to investigate the impact of CCT6A on OSCC cell malignant behaviors and stemness and to explore its potentially interreacted pathways. SCC-15 and HSC-3 cells were transfected with the plasmid loading control overexpression, CCT6A overexpression, control knockout, or CCT6A knockout. Wnt4 overexpression or Notch1 overexpression plasmids were transfected into CCT6A-knockout SCC-15 cells. Cell proliferation, apoptosis, invasion, stemness, Notch, and Wnt pathways were detected in both cell lines, whereas RNA sequencing was only performed in SCC-15 cells. CCT6A was upregulated in five OSCC cell lines, including SCC-15, HSC-3, SAT, SCC-9, and KON, compared to that in the control cell line. In SCC-15 and HSC-3 cells, CCT6A overexpression increased cell proliferation, invasion, sphere formation, CD133, and Sox2 expression, but decreased cell apoptosis; on the contrary, CCT6A knockout exhibited an opposite effect on the above indexes. RNA-sequencing data revealed that the Wnt and Notch pathways were involved in the CCT6A'effect on SCC-15 cell functions. CCT6A positively regulates the Wnt and Notch pathways in SCC-15 and HSC-3 cells. Importantly, it was shown that activation of the Wnt or Notch pathways attenuated the effect of CCT6A knockout on SCC-15 cell survival, invasion, and stemness. CCT6A may promote OSCC malignant behavior and stemness by activating the Wnt and Notch pathways.

SORBS2-Mediated inhibition of malignant behaviors in esophageal squamous cell carcinoma through TIMP3.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is characterized by high invasiveness and poor prognosis. The role of Sorbin and SH3 domain-containing protein 2 (SORBS2) in ESCC remains largely unexplored. METHODS: The expression levels of SORBS2 in ESCC were detected using RNA-seq and proteomics data. The biological functions of SORBS2 in ESCC were investigated through in vivo and in vitro experiments. The mechanism of SORBS2 was explored using RIP-seq technology, which identified the key downstream molecule metalloproteinase-3 (TIMP3). The interaction between SORBS2 and TIMP3, including specific binding sites, was validated through RIP-qPCR and RNA pull-down assays. The impact of altered SORBS2 expression in ESCC on HUVECs was assessed using endothelial tube formation assays. RESULTS: SORBS2 expression was significantly downregulated in ESCC tissues, and its decreased expression was associated with poor prognosis. Overexpression of SORBS2 in ESCC cell lines inhibited cell proliferation, migration, and invasion both in vitro and in vivo. Mechanistically, SORBS2 bound to the 3' UTR of TIMP3 mRNA, enhancing its stability and thereby regulating TIMP3 expression. Rescue experiments demonstrated that increased TIMP3 expression could reverse the promotive effects of SORBS2 knockdown on ESCC, confirming TIMP3 as a critical downstream molecule of SORBS2. Furthermore, downregulation of SORBS2 in ESCC cells was associated with activation of HUVEC functions, whereas upregulation of TIMP3 could reverse this effect. The SORBS2/TIMP3 axis may exert tumor suppressive effects by influencing extracellular matrix degradation. CONCLUSION: This study confirms that SORBS2 inhibits ESCC tumor progression by regulating extracellular matrix degradation through TIMP3, providing a potential therapeutic target for future treatment interventions.

Silencing of keratin 15 impairs viability and mobility while facilitating the doxorubicin chemosensitivity by inactivating the ß­catenin pathway in liver cancer.

Keratin 15 (KRT15) regulates the invasion as well as the stemness and is associated with tumor size and metastasis of several gastrointestinal cancers apart from liver cancer. The present study aimed to explore the effect of KRT15 knockdown on liver cancer malignant behaviors and its interaction with the ß-catenin pathway. Small interfering (si)-KRT15 and si-negative control (NC) were transfected into liver cancer cell lines, followed by the addition or not of CHIR-99021 (a ß-catenin agonist). Cell viability, invasion, apoptosis, and the half maximal inhibitory concentration (IC50) value of doxorubicin (Dox) were then assessed. The present study illustrated that KRT15 gene and protein expression levels were upregulated in most liver cancer cell lines (Huh7, PLC, Hep3B and HepG2) compared to the normal liver cell line THLE-2. si-KRT15 reduced cell viability and invasive cell count while promoting the apoptosis rate in Huh7 and HepG2 cells. In addition, si-KRT15 also reduced the IC50 value of Dox. Furthermore, si-KRT15 inactivated the ß-catenin pathway as reflected by ß-catenin, cyclin D1 and c-Myc expression levels in Huh7 and HepG2 cells. Subsequently, CHIR-99021 treatment increased the cell viability and invasive cell count while reducing the apoptosis rate in Huh7 and HepG2 cells. Concurrently, the IC50 value of Dox was also increased. Notably, CHIR-99021 treatment attenuated the effect of si-KRT15 on mediating the aforementioned Huh7 and HepG2 cell malignant behaviors and Dox chemosensitivity. In conclusion, KRT15 knockdown suppressed viability and mobility but facilitated Dox chemosensitivity via inactivating the ß-catenin pathway in liver cancer, suggesting its potential as a target for liver cancer treatment.

miRNA-195-5p/PSAT1 feedback loop in human triple-negative breast cancer cells.

BACKGROUND: Substantial evidence suggests that non-coding RNAs, such as microRNAs (miRNAs), play a vital role in human cancer. Phosphoserine aminotransferase 1 (PSAT1) is a serine biosynthesis-related member of the aminotransferase family and is closely associated with worse prognosis in triple-negative breast cancer (TNBC). OBJECTIVE: The present study elucidated the molecular mechanisms underlying PSAT1 regulation by miRNAs in TNBC. METHODS: After collecting breast cancer and para-cancerous tissues, expression and functional testing of microRNA-195-5p (miR-195-5p) and PSAT1 were implemented both in vivo and in vitro. RESULTS: Abnormally low miR-195-5p expression was confirmed in TNBC tissues and cells. The specific targeting effect of miR-195-5p on PSAT1 was screened. Our observations revealed that biological tumor behavior was inhibited after miR-195-5p upregulation and this inhibition could be reversed by PSAT1 overexpression both in vivo and in vitro. CONCLUSION: Our study revealed the regulatory axis of miR-195-5p/PSAT1 in TNBC, suggesting a promising targeted therapy for clinical application.

Tumor-suppressive function and mechanism of miR-873-5p in glioblastoma: evidence based on bioinformatics analysis and experimental validation.

This study aims to clarify the mechanistic actions of microRNA-873-5p (miR-873-5p) on glioblastoma (GBM) progression. The most differentially expressed miRNAs were retrieved from the GEO database. It was established that miR-873-5p was downregulated in GBM tissues and cells. Based on in silico prediction and experimental data, HMOX1 was demonstrated to be a target gene of miR-873-5p. Further, miR-873-5p was then ectopically expressed in GBM cells to examine its effect on the malignant behaviors of GBM cells. Overexpression of miR-873-5p inhibited GBM cell proliferation and invasion by targeting HMOX1. HMOX1 promoted SPOP expression by increasing HIF1α expression, thus stimulating GBM cell malignant phenotypes. miR-873-5p suppressed the malignant phenotypes of GBM cells and tumorigenesis in vitro and in vivo by inhibiting the HMOX1/HIF1α/SPOP signaling axis. This study uncovers a novel miR-873-5p/HMOX1/HIF1α/SPOP axis in GBM, providing new insights into GBM progression and therapeutic targets for GBM treatment.

PLK4 inhibitor exhibits antitumor effect and synergizes sorafenib via arresting cell cycle and inactivating Wnt/ß-catenin pathway in anaplastic thyroid cancer.

The anti-tumor effect of polo-like kinase 4 (PLK4) inhibitor has been explored in several solid carcinomas, while its application in anaplastic thyroid cancer (ATC) remains scarce. Hence, the current study aimed to investigate the effect of PLK4 inhibitor on the malignant behaviors of ATC cell lines and its synergistic antitumor effect with sorafenib. C643 and 8305c cells were cultured in various concentrations of centrinone (PLK4 inhibitor) with or without sorafenib. Meanwhile, the cell viability, cell apoptosis, cell cycle and expressions of glycogen synthetase kinase beta (GSK3ß), p-GSK3ß, ß-catenin were determined. PLK4 mRNA and protein expressions were higher in most ATC cell lines than the normal thyroid epithelial cell line (all P < .05). Centrinone decreased cell viability, induced cell apoptosis, arrested cell cycle at G2/M phase and inactivated Wnt/ß-catenin signaling with dose-dependent manners in C643 and 8305c cells (all P < .05). Interestingly, centrinone plus sorafenib further improved antitumor effect (P < .05 at most concentrations), with the highest combination index at 5 nM centrinone plus 4 µM sorafenib in C643 cells, then 4 nM centrinone plus 4 µM sorafenib in C643 cells. Subsequently, centrinone plus sorafenib reduced cell viability, promoted cell apoptosis, facilitated cell cycle at G2/M phase and repressed Wnt/ß-catenin signaling more effectively compared with centrinone or sorafenib monotherapy in C643 and 8305c cells (all P < .05). PLK4 inhibitor exhibits antitumor effect and synergizes sorafenib via arresting cell cycle and inactivating Wnt/ß-catenin pathway in ATC.

2-Bromopalmitate inhibits malignant behaviors of HPSCC cells by hindering the membrane location of Ras protein.

Palmitoylation, which is mediated by protein acyltransferase (PAT) and performs important biological functions, is the only reversible lipid modification in organism. To study the effect of protein palmitoylation on hypopharyngeal squamous cell carcinoma (HPSCC), the expression levels of 23 PATs in tumor tissues of 8 HPSCC patients were determined, and high mRNA and protein levels of DHHC9 and DHHC15 were found. Subsequently, we investigated the effect of 2-bromopalmitate (2BP), a small-molecular inhibitor of protein palmitoylation, on the behavior of Fadu cells in vitro (50 µM) and in nude mouse xenograft models (50 µmol/kg), and found that 2BP suppressed the proliferation, invasion, and migration of Fadu cells without increasing cell apoptosis. Mechanistically, the effect of 2BP on the transduction of BMP, Wnt, Shh, and FGF signaling pathways was tested with qRT-PCR, and its drug target was explored with western blotting and acyl-biotinyl exchange assay. Our results showed that 2BP inhibited the transduction of the FGF/ERK signaling pathway. The palmitoylation level of Ras protein decreased after 2BP treatment, and its distribution in the cell membrane structure was reduced significantly. The findings of this work reveal that protein palmitoylation mediated by DHHC9 and DHHC15 may play important roles in the occurrence and development of HPSCC. 2BP is able to inhibit the malignant biological behaviors of HPSCC cells, possibly via hindering the palmitoylation and membrane location of Ras protein, which might, in turn, offer a low-toxicity anti-cancer drug for targeting the treatment of HPSCC.

SHFM1 deficiency suppresses esophageal squamous cell carcinomas progression via modulating NF­κB signaling and enhancing nature killer cell­mediated tumor surveillance.

Excessive proliferation, metastasis and immune escape are considered to be hallmarks of cancer contributing to tumor progression. Split hand and foot malformation 1 (SHFM1) is highly expressed in various cancers and has been reported to increase malignant behaviors. However, the biological functions of SHFM1 in esophageal squamous cell carcinomas (ESCC) progression remain to be elucidated. An integrated bioinformatics analysis was performed to identify candidate genes in ESCC progression based on GSE microarrays. SHFM1 was found to be profoundly upregulated in ESCC tissues compared with normal tissues and SHFM1 expression was positively associated with poor prognosis. The biological effects of SHFM1 on cell growth, metastasis and immune escape were investigated following depletion or overexpression of SHFM1 in vitro. A xenograft mouse model was established to investigate the effect of SHFM1 on ESCC progression in vivo. SHFM1 overexpression promoted ESCC cell proliferation and migration in vitro as well as tumorigenesis in vivo, while SHFM1 knockdown restored those phenotype changes. Additionally, the present study demonstrated that the effects of SHFM1 on malignant behaviors of ESCC cells were achieved by activating the NF-κB signaling accompanied by increased P65 phosphorylation and nuclear translocation. Furthermore, SHFM1 was also found to regulate the sensitivity of cancer cells to natural killer (NK) cells. Specifically, inhibition of SHFM1 enhanced cell-mediated cell apoptosis and increased NK toxicity, which might involve the downregulation of c-Myc and programmed death-ligand 1, key targets in cancer immunotherapy. In conclusion, these findings suggested that SHFM1 probably promoted ESCC progression by activating the NF-κB pathway and enhancing the resistance of ESCC cells to NK cell cytotoxicity, indicating that SHFM1 may be a promising target for ESCC treatment.