RNA N6-methyladenosine-modified-binding protein YTHDF1 promotes prostate cancer progression by regulating androgen function-related gene TRIM68.

PURPOSE: There is no report about the direct relationship between m6A modification and androgen receptor (AR)-related genes in prostate cancer (PC). We aimed to study the mechanisms of m6A methylation in regulating the pathogenesis of PC from the perspective of AR-related genes. METHODS: qRT-PCR was applied to detect the expression of m6A-related genes in PC cell with or without AR inhibitor. The effects of YTHDF1 knockdown on PC cell viability, apoptosis, migration and invasion were investigated using flow cytometry, wound healing and transwell assays, respectively. The mechanism of YTHDF1 action was investigated using m6A RNA immunoprecipitation (MeRIP) sequencing. The biological functions of YTHDF1 were also explored through in vivo experiments. RESULTS: YTHDF1 was significantly down-regulated in AR inhibitor group. YTHDF1 knockdown significantly decreased AR level, viability and m6A methylation level of PC cells. TRIM68 was identified as a direct target of YTHDF1. Both YTHDF1 and TRIM68 knockdown increased apoptosis, and decreased cell viability, migration, and invasion of PC cells, while TRIM68 overexpression reversed the effects of YTHDF1 knockdown on PC cells. In addition, knockdown of YTHDF1 or TRIM68 significantly decreased the m6A methylation level, and mRNA and protein levels of YTHDF1, TRIM68 and AR in PC cells, while TRIM68 overexpression increased the expression levels above. Furthermore, subcutaneous xenografts of nude mice also revealed that TRIM68 could reverse the effects of YTHDF1 knockdown in PC in vivo. CONCLUSION: This study suggested the key role of YTHDF1-mediated m6A modification in PC progression by regulating androgen function-related gene TRIM68 in PC.

Exosomal miR-18a-5p promotes EMT and metastasis of NPC cells via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

This study investigated the underlying mechanism of miR-18a-5p regulating the proliferation, invasion, and metastasis of nasopharyngeal carcinoma (NPC) cells in vitro and in vivo to indicate the pathogenesis of NPC. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was utilized to determine miR-18a-5p expression level in NPC tissues and cell lines. Besides, 2,5-diphenyl-2 H-tetrazolium bromide (MTT) and colony formation assays were employed to detect the effect of miR-18a-5p expression level on NPC cell proliferation. Wound healing and Transwell assays were utilized to detect the effect of miR-18a-5p on NPC cell invasion and migration. The expression levels of epithelial-mesenchymal transition (EMT)-related proteins (Vimentin, N-cadherin, and E-cadherin) were identified by Western blot assay. After collecting exosomes from CNE-2 cells, it was found that exosomal miR-18a-5p secreted from NPC cells promoted NPC cell proliferation, migration, invasion, and EMT, whereas inhibition of miR-18a-5p expression level led to the opposite results. The dual-luciferase reporter assay showed that BTG anti-proliferation factor 3 (BTG3) was the target gene of miR-18a-5p, and BTG3 could overturn the effect of miR-18a-5p on NPC cells. Xenograft mouse model of NPC nude mice showed that miR-18a-5p promoted NPC growth and metastasis in vivo. This study revealed that exosomal miR-18a-5p derived from NPC cells promoted angiogenesis via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

Deubiquitylase OTUD1 confers Erlotinib sensitivity in non-small cell lung cancer through inhibition of nuclear translocation of YAP1.

Evidence exists suggesting tumor-inhibiting properties of deubiquitylase OTUD1 in various malignancies. We herein investigated the anti-tumor effect and clarified the downstream mechanisms of OTUD1 in the chemoresistance of non-small cell lung cancer (NSCLC) cells. Expression of OTUD1 was examined in NSCLC (PC-9 cells) and erlotinib-resistant NSCLC (PC-9/ER) cell lines. OTUD1 was bioinformatically predicted to be weakly expressed in NSCLC tissue samples and verified in PC-9/ER cells. PC-9/ER cells were subsequently subjected to ectopic expression of OTUD1 alone or combined with SOX9 to dissect out the effect of OTUD1 on the proliferation, chemoresistance and apoptosis in vitro and in vivo. OTUD1 upregulation sensitized NSCLC cells to erlotinib both in vitro and in vivo. In the presence of OTUD1 overexpression, nuclear translocation of YAP1 was inhibited and its expression was inactivated. This effect of OTUD1 was associated with the decreased ubiquitination level of YAP1. SOX9/SPP1 inactivation was the consequence of inhibited nuclear translocation of YAP1. Overexpression of SOX9 reversed the inhibitory effect of OTUD1 on the resistance of NSCLC cells to erlotinib. In conclusion, our study reveals that OTUD1 potentially acts as a tumor suppressor and suppresses erlotinib resistance of NSCLC through the YAP1/SOX9/SPP1 axis, suggesting that OTUD1 may serve as a target for reducing chemoresistance for NSCLC.

ß-catenin correlates with the progression of colon cancers and berberine inhibits the proliferation of colon cancer cells by regulating the ß-catenin signaling pathway.

INTRODUCTION: Berberine was one of the active components in Chinese herb and exerted tumor suppressive role in cancer progression, but the exact antitumor mechanism is still not clearly clarified. In the present study, bioinformatics analysis was performed on COAD patients from TCGA, HPA database, UALCAN and GEPIA 2 platform. We also explored the role of berberine on progression of human colon cancers in vitro and in vivo and clarified weather the antitumor effects of berberine was mediated by Wnt/beta-catenin pathway. METHODS: Cell viability was determined by MTT assay. The protein levels were tested by western blotting and the distribution of ß-catenin was observed by confocal microscope. RESULTS: The results showed the levels of CTNNB1 mRNA was increased in colon cancer patients than normal controls. The diagnostic value of CTNNB1 was AUC = 0.882 (CI:0.854-0.911) with sensitivity of 1.000 and specificity of 0.777. The promoter methylation level of CTNNB1 in COAD patients was significantly decreased. Moreover, univariate analysis and multivariate analysis results showed the expression of CTNNB1 in COAD patients was associated with T stage (p = 0.010), pathological stage (p = 0.025) and perineural invasion (p = 0.025). Furthermore, the in vitro assay results showed ß-catenin signaling was highly activated in human colon cancer cells and berberine inhibited the cell viability of colon cancer cells in vitro and in vivo in a dose-and time-dependent manner. Moreover, berberine induced the translocation of ß-catenin to cytoplasm from nucleus. CONCLUSION: The levels of CTNNB1 mRNA was increased in colon cancer patients than normal controls. Berberine inhibited the proliferation of colon cancer cells by regulating the beta-catenin signaling pathway.

Hepatitis B virus infection does not affect the clinical outcome of anti-programmed death receptor-1 therapy in advanced solid malignancies: Real-world evidence from a retrospective study using propensity score matching.

ABSTRACT: This study aimed to investigate the impact of hepatitis B virus (HBV) infection on the outcome of patients with advanced solid malignancies treated with programmed death receptor-1 (PD-1) inhibitors.We retrospectively included patients treated with PD-1 inhibitors between August 2018 and April 2020. Propensity score matching (PSM) was performed to match the characteristics of the HBV and non-HBV groups. Objective response rate (ORR) and disease control rate (DCR) were compared between HBV and non-HBV groups using χ2 or Fisher exact tests. Kaplan-Meier and log-rank tests were used to analyze overall survival (OS) and progression-free survival (PFS).A total of 120 patients, including 43 (35.8%) with HBV and 77 (64.2%) without HBV, were enrolled. Cases of HBV reactivation were not observed. In the entire study population, ORR and DCR did not significantly differ between both groups. After PSM, the study population comprised 39 patients, 15 with and 24 without HBV. The HBV group had an ORR of 55.6%, whereas the ORR in the non-HBV group was 36.8% (P = .35). Similarly, the DCR was 77.8% in the HBV group, as compared to 68.4% in the non-HBV group (P  = .61). Additionally, HBV infection did not significantly affect OS (P  = .54) and PFS (P  = .64) in the unmatched cohort. Moreover, statistically significant differences regarding OS (P  = .15) and PFS (P  = .23) were also not detected after PSM.In conclusion, the HBV infection status did not impact the therapy response or prognosis of patients treated with PD-1 inhibitors. Further prospective studies are needed to corroborate these findings.