TEAD4 activates PCSK9 to promote stomach adenocarcinoma cell stemness through fatty acid metabolism.

INTRODUCTION: This study attempted to investigate how PCSK9 influences the stemness of stomach adenocarcinoma (STAD) cells. METHODS: CCK-8 and sphere formation assays were used to detect cell viability and stemness. qRT-PCR and western blot were used to detect PCSK9 and TEAD4 expression. The binding relationship was verified by dual luciferase and chromatin immunoprecipitation (ChIP) assays. The effect of TEAD4 activating PCSK9 on the stemness of STAD cells was detected by bioinformatics, BODIPY 493/503, Oil red O, western blot, and kits. In vivo experiments verified the role of the TEAD4/PCSK9 axis in tumor formation in nude mice. RESULTS: PCSK9 and TEAD4 were highly expressed in STAD. PCSK9 was enriched in the FAM pathway. PCSK9 activated the fatty acid metabolism and promoted the proliferation and stemness of STAD cells. TEAD4 as a transcription factor upstream of PCSK9.Cell experiments revealed that knockdown of PCSK9 inhibited STAD cell stemness, whereas further addition of fatty acid inhibitors could attenuate the promoting effect on STAD cell stemness brought by STAD overexpression. Rescue experiments showed overexpressed PCSK9 exerted an inhibitory effect on the stemness of STAD cells brought by TEAD4 knockdown. The hypothesis that TEAD4/PCSK9 axis can promote STAD cell growth was confirmed by in vivo experiments. CONCLUSION: Transcription factor TEAD4 could activate PCSK9 to promote the stemness of STAD cells through FAM. These results added weight to the assumption that TEAD4/PCSK9 axis has the potential to be the therapeutic target that inhibits CSC in STAD.

FBXO22 promotes glioblastoma malignant progression by mediating VHL ubiquitination and degradation.

Glioblastoma (GBM) is the most common malignant primary brain tumor. Despite comprehensive treatment with traditional surgery, radiotherapy, and chemotherapy, the median survival rate is <14.6% and the 5-year survival rate is only 5%. FBXO22, a substrate receptor of the SCF ubiquitin ligases, has been reported to play a promoting role in melanoma, liver cancer, cervical cancer, and other cancers. However, the function of FBXO22 in GBM has not been reported. In the present study, we demonstrate that FBXO22 is highly expressed in glioma and is positively correlated with worse pathological features and shorter survival of GBM patients. We revealed that FBXO22 promotes GBM cell proliferation, angiogenesis, migration, and tumorigenesis in vitro and in vivo. In terms of mechanism, we reveal that FBXO22 decreases VHL expression by directly mediating VHL ubiquitination degradation, which ultimately increases HIF-1α and VEGFA expression. In addition, our data confirm that there are positive correlations among FBXO22, HIF-1α, and VEGFA expression, and there is a negative correlation between FBXO22 and VHL protein expression in glioma patients. Our study strongly indicates that FBXO22 is a promising diagnostic marker and therapeutic target for glioma patients.

PRMT2 promotes RCC tumorigenesis and metastasis via enhancing WNT5A transcriptional expression.

Protein arginine methyltransferase 2 (PRMT2) is involved in several biological processes via histone methylation and transcriptional regulation. Although PRMT2 has been reported to affect breast cancer and glioblastoma progression, its role in renal cell cancer (RCC) remains unclear. Here, we found that PRMT2 was upregulated in primary RCC and RCC cell lines. We demonstrated that PRMT2 overexpression promoted RCC cell proliferation and motility both in vitro and in vivo. Moreover, we revealed that PRMT2-mediated H3R8 asymmetric dimethylation (H3R8me2a) was enriched in the WNT5A promoter region and enhanced WNT5A transcriptional expression, leading to activation of Wnt signaling and malignant progression of RCC. Finally, we confirmed that high PRMT2 and WNT5A expression was strongly correlated with poor clinicopathological characteristics and poor overall survival in RCC patient tissues. Our findings indicate that PRMT2 and WNT5A may be promising predictive diagnostic biomarkers for RCC metastasis. Our study also suggests that PRMT2 is a novel therapeutic target in patients with RCC.

Multicenter, single-arm, phase II study (CAP) of radiotherapy plus liposomal irinotecan followed by camrelizumab and anti-angiogenic treatment in advanced solid tumors.

Introduction: Combination therapeutic mode is likely to be the key to enhance the efficacy of immunotherapy in a wider range of cancer patients. Herein, we conducted an open-label, single-arm, multicenter, phase II clinical trial that enrolled patients with advanced solid tumors who had progressed after standard treatments. Methods: Radiotherapy of 24 Gy/3 fractions/3-10 days was given to the targeted lesions. Liposomal irinotecan (80mg/m2, dose could be adjusted to 60 mg/m2 for intolerable cases) was intravenously (IV) administered once within 48 hours after radiotherapy. Then, camrelizumab (200mg IV, q3w) and anti-angiogenic drugs were given regularly until disease progression. The primary endpoint was objective response rate (ORR) in the target lesions evaluated by investigators per RECIST 1.1. The secondary endpoints were disease control rate (DCR) and treatment-related adverse events (TRAEs). Results: Between November 2020 and June 2022, 60 patients were enrolled. The median follow-up was 9.0 months (95% confidence interval (CI) 5.5-12.5). Of 52 evaluable patients, the overall ORR and DCR were 34.6% and 82.7%, respectively. Fifty patients with target lesions were evaluable, the ORR and DCR of the target lesions were 35.3% and 82.4%, respectively. The median progression-free survival was 5.3 months (95% CI 3.6, 6.2), and the median overall survival was not reached. TRAEs (all grades) occurred in 55 (91.7%) patients. The most common grade 3-4 TRAEs were lymphopenia (31.7%), anemia (10.0%), and leukopenia (10.0%). Conclusion: The combination of radiotherapy, liposomal irinotecan, camrelizumab, and anti-angiogenesis therapy demonstrated promising anti-tumor activity and well tolerance in various advanced solid tumors. Clinical trial registration: https://clinicaltrials.gov/ct2/home, identifier NCT04569916.

TRIM21 attenuates renal carcinoma lipogenesis and malignancy by regulating SREBF1 protein stability.

BACKGROUND: Metabolic reprogramming is a hallmark of various cancers. Targeting metabolic processes is a very attractive treatment for cancer. Renal cell carcinoma (RCC) is a type of metabolic disease, and the lipidomic profile of RCC is significantly altered compared with that of healthy tissue. However, the molecular mechanism underlying lipid metabolism regulation in RCC is not clear. METHODS: The XF long-chain fatty acid oxidative stress test kits were used to assess the dependence on long-chain fatty acids and mitochondrial function after knockdown TRIM21 in RCC cells. The effect of TRIM21 on the lipid content in RCC cells was determined by metabolomics analysis, Oil Red O staining, and cellular Nile red staining. qRT-PCR and western blot were used to explore the relationship between TRIM21 and lipogenesis, and then the key molecule sterol regulatory element binding transcription factor 1 (SREBF1) was identified to interact with TRIM21 by immunoprecipitation, which was also identified in an orthotopic model. Subsequently, the relevance and clinical significance of TRIM21 and SREBF1 were analyzed by The Cancer Genome Atlas (TCGA) database, and 239 tissues were collected from RCC patients. RESULTS: TRIM21 silencing attenuated the dependence of RCC cells on fatty acids, and enhanced lipid accumulation in RCC cells. TRIM21 overexpression significantly decreased lipid contents by decreasing the expression of lipogenic enzymes via ubiquitination-mediated degradation of SREBF1. SREBF1 is critical for TRIM21-mediated lipogenesis inhibition in vitro and in vivo. Moreover, TRIM21 expression is negatively correlated with SREBF1 expression, and TRIM21-SREBF1 is a reliable combinational biomarker for RCC prognosis. CONCLUSION: The findings from this study reveal a novel pathway through which TRIM21 inhibits the lipid metabolism process of RCC and shed light on the development of targeted metabolic treatment and prognosis diagnosis of RCC.

GSK3326595 is a promising drug to prevent SARS-CoV-2 Omicron and other variants infection by inhibiting ACE2-R671 di-methylation.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused COVID-19 epidemic is worsening. Binding of the Spike1 protein of SARS-CoV-2 with the angiotensin-converting enzyme 2 (ACE2) receptor mediates entry of the virus into host cells. Many reports show that protein arginine methylation by protein arginine methyltransferases (PRMTs) is important for the functions of these proteins, but it remains unclear whether ACE2 is methylated by PRMTs. Here, we show that PRMT5 catalyses ACE2 symmetric dimethylation at residue R671 (meR671-ACE2). We indicate that PRMT5-mediated meR671-ACE2 promotes SARS-CoV-2 receptor-binding domain (RBD) binding with ACE2 probably by enhancing ACE2 N-glycosylation modification. We also reveal that the PRMT5-specific inhibitor GSK3326595 is able to dramatically reduce ACE2 binding with RBD. Moreover, we discovered that meR671-ACE2 plays an important role in ACE2 binding with Spike1 of the SARS-CoV-2 Omicron, Delta, and Beta variants; and we found that GSK3326595 strongly attenuates ACE2 interaction with Spike1 of the SARS-CoV-2 Omicron, Delta, and Beta variants. Finally, SARS-CoV-2 pseudovirus infection assays uncovered that PRMT5-mediated meR671-ACE2 is essential for SARS-CoV-2 infection in human cells, and pseudovirus infection experiments confirmed that GSK3326595 can strongly suppress SARS-CoV-2 infection of host cells. Our findings suggest that as a clinical phase II drug for several kinds of cancers, GSK3326595 is a promising candidate to decrease SARS-CoV-2 infection by inhibiting ACE2 methylation and ACE2-Spike1 interaction.

Tumour-associated macrophages enhance breast cancer malignancy via inducing ZEB1-mediated DNMT1 transcriptional activation.

BACKGROUND: DNMT1 has been shown to be highly expressed in a variety of cancers, including breast cancer. However, the mechanism is not very clear. Therefore, we aim to reveal the mechanism of DNMT1 highly express in breast cancer. And we also want to explore the role of DNMT1 in tumour microenvironment promoting breast cancer progression. RESULTS: In this study, we demonstrate that DNMT1 is overexpressed in breast cancer and that DNMT1 promotes breast cancer tumorigenesis and metastasis. We discovered that ZEB1 activates DNMT1 expression in breast cancer cells by recruiting P300 binding to the DNMT1 promoter and increasing its acetylation. Moreover, we revealed that tumour-associated macrophages (TAMs) increase DNMT1 expression in breast cancer cells via the IL-6-pSTAT3-ZEB1-DNMT1 axis in the tumour microenvironment. DNMT1 is required for TAM-mediated breast cancer cell migration. In addition, we confirmed that there were positive correlations among CD163 (TAM marker) expression, ZEB1 expression and DNMT1 expression in breast cancer patient tissues. CONCLUSIONS: Our study indicates that DNMT1 is necessary for TAM-mediated breast cancer metastasis. Decitabine (DAC), as a specific DNA methylation inhibitor and FDA-approved drug, is a bona fide drug for breast cancer treatment.

Long noncoding RNA SH3PXD2A-AS1 promotes NSCLC proliferation and accelerates cell cycle progression by interacting with DHX9.

As the most commonly diagnosed lung cancer, non-small cell lung carcinoma (NSCLC) is regulated by many long noncoding RNAs (lncRNAs). In the present study, we found that SH3PXD2A-AS1 expression in NSCLC tissues was upregulated compared with that in normal lung tissues in The Cancer Genome Atlas (TCGA) database by using the GEPIA website. K-M analysis was performed to explore the effects of this molecule on the survival rate in NSCLC. The results demonstrated that SH3PXD2A-AS1 expression was increased in human NSCLC, and high SH3PXD2A-AS1 expression was correlated with poor overall survival. SH3PXD2A-AS1 promotes lung cancer cell proliferation and accelerates cell cycle progression in vitro. Animal studies validated that knockdown of SH3PXD2A-AS1 inhibits NSCLC cell proliferation in vivo. Mechanically, SH3PXD2A-AS1 interacted with DHX9 to enhance FOXM1 expression, promote tumour cell proliferation and accelerate cell cycle progression. Altogether, SH3PXD2A-AS1 promoted NSCLC growth by interacting with DHX9 to enhance FOXM1 expression. SH3PXD2A-AS1 may serve as a promising predictive biomarker for the diagnosis and prognosis of patients with NSCLC.

Transketolase promotes colorectal cancer metastasis through regulating AKT phosphorylation.

Transketolase (TKT) which is an important metabolic enzyme in the pentose phosphate pathway (PPP) participates in maintaining ribose 5-phosphate levels. TKT is necessary for maintaining cell growth. However, we found that in addition to this, TKT can also affect tumor progression through other ways. Our previous study indicate that TKT could promote the development of liver cancer by affecting bile acid metabolism. And in this study, we discovered that TKT expression was remarkably upregulated in colorectal cancer, abnormal high expression of TKT is associated with poor prognosis of colorectal cancer. Additionally, TKT promoted colorectal cancer cell growth and metastasis. Further study demonstrated that TKT interacted with GRP78 and promoted colorectal cancer cell glycolysis through increasing AKT phosphorylation, thereby enhancing colorectal cancer cell metastasis. Thus, TKT is expected to become an indicator for judging the prognosis of colorectal cancer, and provide a theoretical basis for drug development of new treatment targets for colorectal cancer.

FBXO22 Promotes Growth and Metastasis and Inhibits Autophagy in Epithelial Ovarian Cancers via the MAPK/ERK Pathway.

E3 ubiquitin ligase F-box only protein 22 (FBXO22), which targets the key regulators of cellular activities for ubiquitylation and degradation, plays an important role in tumorigenesis and metastasis. However, the function of FBXO22 in epithelial ovarian cancers has not been reported. This study aims to explore the biological function of FBXO22 in epithelial ovarian cancers progression and metastasis and its specific regulation mechanism. Immunohistochemistry analysis of tissue microarray was performed to evaluate the expression of FBXO22 in epithelial ovarian cancers patients. The proliferative ability of epithelial ovarian cancers cells was examined by the CCK8. The metastasis ability was detected by the wound healing assay, migration and invasion assays. Western blot was used to verify the relationship between FBXO22 expression and mitogen-activated protein kinase related proteins. Autophagic flux was detected by electron microscopy, mRFP-GFP-LC3 adenovirus, lysosomal tracker and western blot. For in vivo experiments, the effect of FBXO22 on epithelial ovarian cancers resistance was observed in a xenograft tumor model and a metastatic mice model. We found that FBXO22 expression was significantly increased in epithelial ovarian cancers tissues and was closely correlated with clinical pathological factors. As a result, we found that FBXO22 promoted the growth and metastasis, as well as inhibited the autophagy flux. In addition, we identified that FBXO22 performed these functions via the MAPK/ERK pathway. Our results first reported the function of FBXO22 in epithelial ovarian cancer and the correlation between FBXO22 and autophagy, suggesting FBXO22 as a novel target of epithelial ovarian cancers assessment and treatment.

miR-504 Promoted Gastric Cancer Cell Proliferation and Inhibited Cell Apoptosis by Targeting RBM4.

BACKGROUND: The purpose of this study was to explore the role and underlying mechanism of miR-504 and RBM4 in gastric cancer. METHODS: The qRT-PCR or Western blot was performed to determine the expressions of miR-504 and RBM4 in the gastric cancer tissues and normal tissues. Human SGC-7901 cells were transfected with miR-504 mimic/inhibitor or pcDNA-RBM4. Cell proliferation and cell apoptosis were assessed by colony formation assay and flow cytometry, respectively. Luciferase reporter gene assays were used to investigate interactions between miR-504 and RBM4 in SGC-7901 cells. RESULTS: The relative expression of miR-504 was significantly upregulated in the gastric cancer group (n = 25) than in the paired normal group (n = 25), but the relative RBM4 expression was remarkably downregulated in the gastric tumor group, compared with the normal group. Additionally, miR-504 overexpression increased the viability of gastric cancer cells. Moreover, RBM4 is a functional target of miR-504 in gastric cancer cells. miR-504 was further confirmed to promote SGC-7901 cell proliferation and inhibit cell apoptosis by downregulation RBM4 in vitro. CONCLUSIONS: miR-504 promotes gastric cancer cell proliferation and inhibits cell apoptosis by targeting RBM4, and this provides a potential diagnostic biomarker and treatment for patients with gastric cancer.

Long Noncoding RNA MLK7-AS1 Promotes Non-Small-Cell Lung Cancer Migration and Invasion via the miR-375-3p/YWHAZ Axis.

Long noncoding RNAs act essential regulators in lung cancer tumorigenesis. Our research aimed to investigate the potential function and molecular mechanisms of MLK7-AS1 in NSCLC (non-small-cell lung cancer). QRT-PCR results indicated that the MLK7-AS1 expression level was upregulated in NSCLC cells and tissues. MLK7-AS1 strengthened cell migration and invasion in H1299 and A549 cells. Luciferase reporter assay found that MLK7-AS1 functioned as an endogenous sponge for miR-375-3p. Transwell assay results showed that miR-375-3p suppressed cell migration and invasion in H1299 and A549 cells. YWHAZ was confirmed as a target gene of miR-375-3p by Targetscan. YWHAZ overexpression promoted the invasion of H1299 and A549 cells. MLK7-AS1 upregulated YWHAZ expression and enhanced H1299 and A549 cell invasion by sponging miR-375-3p. MLK7-AS1 improved the metastasis ability of A549 in vivo. In conclusion, MLK7-AS1 was identified as a novel oncogenic RNA in NSCLC and can function as a potential therapeutic target for NSCLC treatment.

Trim21-mediated HIF-1α degradation attenuates aerobic glycolysis to inhibit renal cancer tumorigenesis and metastasis.

Tripartite motif-containing 21 (Trim21) is mainly involved in antiviral responses and autoimmune diseases. Although Trim21 has been reported to have a cancer-promoting or anticancer effect in various tumours, its role in renal cell cancer (RCC) remains to be elucidated. In this study, we demonstrate that Trim21 is downregulated in primary RCC tissues. Low Trim21 expression in RCC is correlated with poor clinicopathological characteristics and short overall survival. Moreover, we illustrate that Trim21 inhibits RCC cells glycolysis through the ubiquitination-mediated degradation of HIF-1α, which inhibits the proliferation, tumorigenesis, migration, and metastasis of RCC cells in vitro and in vivo. Our findings show that Trim21 may become a promising predictive biomarker for the prognosis of patients with RCC.

lncRNA SNHG14 promotes oncogenesis and immune evasion in diffuse large-B-cell lymphoma by sequestering miR-152-3p.

This study aimed to explore the role of small nucleolar RNA host gene 14 (SNHG14) in the pathogenesis of diffuse large-B-cell lymphoma (DLBCL). DLBCL cell lines (OCI-Ly7 and OCI-Ly3) and specimens from patients were collected to evaluate the roles of SNHG14 in DLBCL pathogenesis. The results showed that SNHG14 expression increased and miR-152-3p expression decreased in DLBCL tissues and cell lines, indicating a negative correlation between miR-152-3p and SNHG14 expression. Moreover, SNHG14 was found to promote DLBCL growth, migration, and EMT-like processes in vitro, and directly inhibits miR-152-3p gene expression via sequestration of the miR-152-3p transcripts in DLBCL. Additionally, SNHG14/miR-152-3p inhibits apoptosis and promotes cell proliferation on cytotoxic T lymphocytes (CTLs) in DLBCL via the PD-1/PD-L1 checkpoint. Furthermore, both the immune escape and progression of DLBCL are advanced by SNHG14 expression via its interactions with miR-152-3p. Collective, this suggests that SNHG14 is a potential diagnostic, prognostic, and therapeutic target for DLBCL.

MiR-34a suppresses the proliferation and invasion of gastric cancer by modulating PDL1 in the immune microenvironment.

OBJECTIVES: As one of the most serious malignant carcinomas that threaten the life of sufferers constantly, gastric cancer has attracted a lot of interest among researchers. miR-34a, a member of hundreds of microRNAs (miRNAs), has been elucidated to exert a suppressive role in gastric cancer tumorgenesis based on previous extensive studies. Our study was performed with the aim to explore the functional effects of miR-34a and its predictive target programmed death ligand 1 (PDL1) in gastric cancer development. METHODS: We employed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western Blot analysis to investigate the regulatory effect of miR-34a on PDL1 mRNA and the corresponding protein expression. The CCK-8 and colony formation assays were used to validate the influence of the combination of miR-34a and PDL1 on the proliferation of gastric tumor cells. Meanwhile, the migration and invasion of gastric tumor cells were measured using Transwell assay. RESULTS: PDL1 was targeted and negatively modulated by miR-34a. In addition, the re-expression of miR-34a suppressed the proliferation as well as the migration and invasion of gastric tumor cells, whereas PDL1 reduced the aforementioned inhibitory effect. CONCLUSIONS: PDL1 is the downstream gene of miR-34a, which can act as an anti-oncogene in gastric cancer. The miR-34a/PDL1 axis might provide a promising anticancer therapeutic approach for the clinical diagnosis, treatment, and prognosis of gastric cancer.

Naringin inhibits colorectal cancer cell growth by repressing the PI3K/AKT/mTOR signaling pathway.

In recent years, the incidence of colorectal cancer (CRC) has increased and research into new treatment methods for CRC has become a hot topic. Naringin has an inhibitory effect on the PI3k/AKT/mTOR signaling pathway in various tumor cell types and the effect of naringin is closely related to the occurrence and proliferation of tumor cells. The aim of this present study was to investigate whether naringin could inhibit the proliferation of CRC cells by inhibiting the PI3K/AKT/mTOR signaling pathway. This could provide a more mechanism-based treatment for CRC. MTT assays were used to detect the proliferation of CRC cells treated with various concentrations of naringin. The degree of apoptosis and the expression of apoptosis-related proteins (Bcl-2 and Bax) in CRC cells stimulated by naringin was detected using flow cytometry and western blot assays, respectively. The expression levels of PI3K/AKT/mTOR-related proteins [PI3K, AKT, mTOR, phosphorylated (p)-PI3K, p-AKT and p-mTOR] after naringin stimulation in CRC cells were detected using western blot assays. Naringin inhibited the proliferation of CRC cells in a dose-dependent manner. Naringin promoted the apoptosis of CRC cells and inhibited the activation of the PI3K/AKT/mTOR signaling pathway in a dose-dependent manner. The results demonstrated that naringin may be a promising therapeutic agent for the treatment of CRC, which may inhibit the proliferation of CRC cells and induce apoptosis by inhibiting the PI3K/AKT/mTOR signaling pathway.

Reduced expression of annexin A1 promotes gemcitabine and 5-fluorouracil drug resistance of human pancreatic cancer.

Intrinsic chemoresistance is the main reason for the failure of human pancreatic ductal adenocarcinoma (PDAC) therapy. To identify the candidate protein, we compared the protein expression profiling of PDAC cells and its distinct surviving cells following primary treatment with gemcitabine (GEM) and 5-fluorouracil (5-FU) by two-dimensional electrophoresis combined with liquid chromatography-mass spectrometry or mass spectrometry. A total of 20 differentially expressed proteins were identified, and annexin A1 (ANXA1) was analyzed for further validation. The functional validation showed that the downregulation of ANXA1 contributes to GEM and 5-FU resistance in PDAC cells through protein kinase C/c-Jun N-terminal kinase/P-glycoprotein signaling pathway. Our findings provide a platform for the further elucidation of the underlying mechanisms of PDAC intrinsic chemoresistance and demonstrated that ANXA1 may be a valid marker for anticancer drug development.

PTBP3 contributes to colorectal cancer growth and metastasis via translational activation of HIF-1α.

BACKGROUND: Colorectal cancer (CRC) remains the fourth most common cause of cancer-related mortality worldwide. We aimed to identify key molecules and signalling pathways mediating CRC growth and metastasis. Polypyrimidine tract-binding protein 3 (PTBP3) is a member of PTB family. A prooncogenic role for PTBP3 has also been discovered in several kinds of tumors. However, the expression and biological functions of the PTBP3 are still unknown in CRC. METHODS: We analysed the expression levels of PTBP3 using tissue microarray containing 568 CRC tissues and corresponding non-tumor adjacent tissues. The correlations between the PTBP3 expression level and clinicopathological features were evaluated using the chi-square test. The functional characterization for the role and molecular mechanism of PTBP3 in CRC was investigated through a series of in vitro and in vivo experiments. RESULTS: We showed that PTBP3 expression was increased in human CRC, and high PTBP3 expression was correlated with poor five-year overall survival and disease-free survival. Moreover, PTBP3 promoted tumor cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. PTBP3 enhanced HIF-1α protein expression by directly binding to the 5'UTR HIF-1α mRNA and activated translation of HIF-1α. Furthermore, HIF-1α was responsible for PTBP3-induced cell migration and invasion. CONCLUSIONS: PTBP3 appears to be a novel oncogene of CRC through binding to the IRES region of HIF-1α mRNA, which regulates HIF-1α translation. PTBP3 can serve as a promising predictive biomarker for recurrence and prognosis in patients with CRC.

PinX1 represses renal cancer angiogenesis via the mir-125a-3p/VEGF signaling pathway.

BACKGROUND: PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a tumor suppressor in various tumors. However, the molecular mechanism underlying PinX1's role in cancer development and progression remains unclear. In this study, we aimed to uncover the new molecular mechanism and role of PinX1 in renal cell carcinoma (RCC) progression. METHODS: We used miRNA microarray to detect the different expressed miRNAs upon PinX1 knockdown. Chromatin immunoprecipitation and Luciferase reporter assays were taken to identify the molecular mechanism of PinX1 in regulating mir-125-3p. In situ hybridization was performed to analyze the expression of mir-125a-3p in RCC using tissue microarray. The correlations between the mir-125a-3p expression level and clinicopathological features were evaluated using the χ2 test. The role and molecular mechanism of PinX1 in RCC angiogenesis were investigated through a series of in vitro and in vivo experiments. RESULTS: In this study, we discovered a new molecular mechanism of PinX1, in which PinX1 transcriptionally activated mir-125a-3p expression, thereby inhibiting the expression of vascular endothelial growth factor (VEGF), which is the target gene of mir-125a-3p. PinX1 also repressed tumor angiogenesis by increasing the mir-125a-3p expression in renal cancer. Moreover, the loss of mir-125a-3p expression was manifested in patients with RCC, and low miR-125a-3p levels correlated with poor survival of these patients. CONCLUSIONS: PinX1 represses renal cancer angiogenesis through mir-125a-3p/VEGF signal pathway. The miR-125a-3p may be a candidate clinical prognostic marker and a novel therapeutic target in RCC.