A Large Genetic Causal Analysis of the Gut Microbiota and Urological Cancers: A Bidirectional Mendelian Randomization Study.

BACKGROUND: Several observational studies and clinical trials have shown that the gut microbiota is associated with urological cancers. However, the causal relationship between gut microbiota and urological cancers remains to be elucidated due to many confounding factors. METHODS: In this study, we used two thresholds to identify gut microbiota GWAS from the MiBioGen consortium and obtained data for five urological cancers from the UK biobank and Finngen consortium, respectively. We then performed a two-sample Mendelian randomization (MR) analysis with Wald ratio or inverse variance weighted as the main method. We also performed comprehensive sensitivity analyses to verify the robustness of the results. In addition, we performed a reverse MR analysis to examine the direction of causality. RESULTS: Our study found that family Rikenellaceae, genus Allisonella, genus Lachnospiraceae UCG001, genus Oscillibacter, genus Eubacterium coprostanoligenes group, genus Eubacterium ruminantium group, genus Ruminococcaceae UCG013, and genus Senegalimassilia were related to bladder cancer; genus Ruminococcus torques group, genus Oscillibacter, genus Barnesiella, genus Butyricicoccus, and genus Ruminococcaceae UCG005 were related to prostate cancer; class Alphaproteobacteria, class Bacilli, family Family XI, genus Coprococcus2, genus Intestinimonas, genus Lachnoclostridium, genus Lactococcus, genus Ruminococcus torques group, and genus Eubacterium brachy group were related to renal cell cancer; family Clostridiaceae 1, family Christensenellaceae, genus Eubacterium coprostanoligenes group, genus Clostridium sensu stricto 1, and genus Eubacterium eligens group were related to renal pelvis cancer; family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum were related to testicular cancer. Comprehensive sensitivity analyses proved that our results were reliable. CONCLUSIONS: Our study confirms the role of specific gut microbial taxa on urological cancers, explores the mechanism of gut microbiota on urological cancers from a macroscopic level, provides potential targets for the screening and treatment of urological cancers, and is dedicated to providing new ideas for clinical research.

Assessment of an exhaled breath test using ultraviolet photoionization time-of-flight mass spectrometry for the monitoring of kidney transplant recipients.

Continuous monitoring for immunosuppressive status, infection and complications are a must for kidney transplantation (KTx) recipients. Traditional monitoring including blood sampling and kidney biopsy, which caused tremendous medical cost and trauma. Therefore, a cheaper and less invasive approach was urgently needed. We thought that a breath test has the potential to become a feasible tool for KTx monitoring. A prospective-specimen collection, retrospective-blinded assessment strategy was used in this study. Exhaled breath samples from 175 KTx recipients were collected in West China Hospital and tested by online ultraviolet photoionization time-of-flight mass spectrometry (UVP-TOF-MS). The classification models based on breath test performed well in classifying normal and abnormal values of creatinine, estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN) and tacrolimus, with AUC values of 0.889, 0.850, 0.849 and 0.889, respectively. Regression analysis also demonstrated the predictive ability of breath test for clinical creatinine, eGFR, BUN, tacrolimus level, as the predicted values obtained from the regression model correlated well with the clinical true values (p < 0.05). The findings of this investigation implied that a breath test by using UVP-TOF-MS for KTx recipient monitoring is possible and accurate, which might be useful for future clinical screenings.

Circ_0057558 accelerates the development of prostate cancer through miR-1238-3p/SEPT2 axis.

BACKGROUND: Prostate cancer (PCa) is one of the most common malignant tumors in males with high morbidity and mortality. Existing studies have demonstrated that circ_0057558 may be a molecular marker affecting PCa. However, its detailed roles in PCa remain unclear. METHODS: The levels of circ_0057558, miR-1238-3p and Septin 2 (SEPT2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay, colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry assay, wound healing assay, transwell assay and tube formation assay were conducted for cell function identification. Xenograft tumor experiment was used to test the effect of circ_0057558 in vivo. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to determine the relationships between miR-1238-3p and circ_0057558 or SEPT2. RESULTS: We identified that circ_0057558 level was elevated in PCa, and silencing circ_0057558 restrained PCa cell proliferation, survival, migration, invasion and angiogenesis. Circ_0057558 could sponge miR-1238-3p, and SEPT2 was the target of miR-1238-3p. Circ_0057558 promoted the expression of SEPT2 by negatively regulating miR-1238-3p, resulting in promotion of PCa progression. The effects of circ_0057558 knockdown in PCa development were overturned by the lack of miR-1238-3p. Also, overexpression of SEPT2 abolished the suppressive impacts of miR-1238-3p on PCa progression. CONCLUSION: As a tumor promoter, circ_0057558 regulated the expression of miR-1238-3p and SEPT2 and facilitated PCa progression. These results indicated that circ_0057558 was a potential therapeutic marker of PCa.

A Ferroptosis-Related Gene Signature for Predicting Survival and Immunotherapy Effect in Renal Cancer.

Background: Most recently, no efficient prognostic indictor is present for kidney cancer. Thus, we aimed to build and validate a new prognostic gene signature for renal cancer patients using the Cancer Genomic Atlas (TCGA). Methods: A "time-dependent receiver operating characteristic (tROC)" curve was generated, and a log-rank test was performed to assess the performance of the biomarker in training and validation. A "ferroptosis-related gene signature" was developed. In different training and validations sets, tROC and log-rank test were used to validate the biomarker's performance. Results: In the training set with a P value less than 0.01 and the validation set, the "gene signature" was significantly correlated with survival. Eventually, it was found that the ferroptosis-related gene signature was directly correlated with immune score and the score of tumor mutation, suggesting its role in predicting response to immunotherapy. Conclusion: We developed and validated a "ferroptosis-related gene signature" that can be sued for patients with kidney cancer. It can also assist in facilitating the plan for treatment and risk stratification.

Epigallocatechin-3-gallate induces autophagy-related apoptosis associated with LC3B II and Beclin expression of bladder cancer cells.

The incidence of bladder cancer in traditional green tea-consuming countries was dramatically lower than low green tea-consuming countries. Epigallocatechin-3-gallate (EGCG), an active ingredient extracted from green tea, showed effective inhibition of formation and progression of many tumors. However, whether autophagy involved in this tumor-suppression mechanism of EGCG on bladder cancer was still unclear. In this study, we demonstrated low concentration of EGCG-induced proliferation inhibition and increased apoptosis in bladder cancer cell lines (5,637 and T24 cells) indicated by the increased expression of apoptosis-related protein (caspase9, caspase3 and BAX). In addition, low dose of EGCG also regulated autophagy pathway associated protein (LC3B II and Beclin) expression and this autophagy pathway was blocked by PI3K/AKT inhibitor; moreover, knockdown of ATG5 reversed EGCG-induced apoptosis in 5,637 cells, indicating that EGCG might inhibit the bladder cancer through autophagy pathway. Our findings indicated that EGCG should be considered as a novel therapy for bladder cancer treatment by regulating autophagy pathway. PRACTICAL APPLICATIONS: Our research proved EGCG from green tea could be used as an effective anti-tumor ingredient by revealing another mechanism that epigallocatechin-3-Gallate inhibited bladder cancer cells via inducing autophagy-related apoptosis. And green tea could be considered as a kind of tumor-preventing beverage.

Methylation-induced silencing of miR-34a enhances chemoresistance by directly upregulating ATG4B-induced autophagy through AMPK/mTOR pathway in prostate cancer.

miR-34a is downregulated and a regulator of drug resistance in prostate cancer (PCa). However, the mechanism of miR-34a in chemoresistance of PCa remains largely unknown. In the present study, we first confirmed the hypermethylation­induced downregulation of miR-34a in PCa tissues and cell lines, PC-3 and DU145. Additionally, transfection of miR-34a mimics and demethylation by 5-azacytidine both resulted in the upregulation of miR-34a expression, which further induced declined cell proliferation and the enhanced apoptosis in PCa cells. Upregulation of miR-34a enhanced the chemosensitivity of PC-3 and DU145 cells. Furthermore, overexpression of miR-34a reduced the expression of autophagy-related proteins, ATG4B, Beclin-1 and LC3B II/I in PCa cells and demethylation treatment showed similar effect. ATG4B was confirmed directly by miR-34a targeting in PCa. Finally, downregulated p-AMPK and upregulated p-mTOR were detected in miR-34a overexpressed PCa cells. Collectively, miR-34a enhances chemosensitivity by directly downregulating ATG4B-induced autophagy through AMPK/mTOR pathway in PCa.

microRNA-32 induces radioresistance by targeting DAB2IP and regulating autophagy in prostate cancer cells.

The aberrant expression of microRNAs (miRNAs/miRs) has been found in numerous cancer types. miR-32 is an oncomiR in prostate cancer (PCa), however, the mechanisms by which miR-32 functions as a regulator of radiotherapy response and resistance in PCa are largely unknown. In the present study, it was found that DAB2 interacting protein (DAB2IP), the miR-32-dependent tumor-suppressor gene, was downregulated and induced autophagy and inhibited radiotherapy-induced apoptosis in PCa cells. miR-32 expression was upregulated or overexpressed in PCa, and miR-32 inhibited DAB2IP expression through a direct binding site within the DAB2IP 3' untranslated region. miR-32 mimics enhanced tumor cell survival and decreased radiosensitivity in the PCa cells, which were reversed by miR-32 inhibitor. Flow cytometric analysis revealed that overexpressed miR-32, consistent with the DAB2IP-knockdown results, reduced ionizing radiation (IR)-induced cell apoptosis, which was restored by 4 nM brefeldin A treatment. More significantly, the overexpression of miR-32 and the knockdown of DAB2IP enhanced autophagy in the IR-treated PCa cells. miR-32 regulated the expression of autophagy-related proteins, such as DAB2IP, Beclin 1 and Light chain 3ß I/II, as well as phosphorylation of S6 kinase and mammalian target of rapamycin. In conclusion, these data provide novel insights into the mechanisms governing the regulation of DAB2IP expression by miR-32 and their possible contribution to autophagy and radioresistance in PCa.

Suppression of Cellular Proliferation and Invasion by HMGB1 Knockdown in Bladder Urothelial Carcinoma Cells.

HMGB1, which acts as a DNA chaperone to help maintain nuclear homeostasis, was reported to play a prominent role in cancer progression, angiogenesis, invasion, and metastasis development. Increased expression of HMGB1 has been observed in several tumor entities. However, the molecular mechanisms of HMGB1 in tumorigenesis of bladder cancer have rarely been reported. In the present study, real-time quantitative RT-PCR analysis revealed that the expression of HMGB1 in human bladder urothelial carcinoma (BUC) cells was much higher than that in human normal urethra epithelial cells. In order to investigate the role of HMGB1 in BUC cells, RNA interference and Talen-mediated gene knockout (KO) were used to knockdown and knockout HMGB1, respectively, in BUC cell lines BIU-87 and T24. HMGB1 knockdown/out greatly inhibited proliferation, invasion, and cell cycle G1/S transition of BUC cells. The decrease in cell viability caused by HMGB1 knockdown/out was due to an increase in apoptosis via Bax/Bcl-2, both of which were important molecules involved in the apoptotic pathway. We then investigated the effect of HMGB1 knockdown/out on the sensitivity of BUC cells treated with the anticancer drug cisplatin. Knockdown or knockout of HMGB1 rendered BUC cells more sensitive to cisplatin. The decreased expression of LC3-II and Beclin 1, which resulted in decreased levels of autophagy, could probably explain this phenomenon. Thus, HMGB1 may become a novel promising candidate for the prognosis and therapy for bladder cancer.