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IntroductionThe use of antibiotics may induce the changes in gut microbiota. Previous studies have shown conflicting results on whether the changed gut microbiota by antibiotics can be recovered. Our study aims to investigate whether the gut microbiota could be recovered after a single dose of oral co-amoxiclav before transrectal ultrasound-guided transperineal prostate biopsy (TPPBx) in 5 weeks’ time.MethodsFifteen patients with elevated serum prostate-specific antigen (PSA) were recruited to provide pre-antibiotic and post-antibiotic fecal samples. The V4 region of 16S rRNA was sequenced. Analysis was performed by QIIME2. Alpha- and beta-diversities were analyzed, as well as the differential enrichment by Linear discriminant analysis Effect Size (LEfSe) analysis.ResultsBoth the alpha- and beta-diversities of the pre- and post-antibiotic fecal samples were significantly different. Genera that are associated with alleviation of inflammation were enriched in the pre-antibiotic fecal samples, while the inflammation-associated genera were more enriched in the post-antibiotic fecal samples.ConclusionA single dose of oral co-amoxiclav before TPPBx could have led to a change of gut microbiota that cannot be recovered in 5 weeks' time. Microbiome studies on prostate cancer patients should be cautioned on the use of post-prostate biopsy fecal sampling. Further studies should be conducted for the impact on gut microbiome for TPPBx alone.

Spermidine/spermine N

Urinary bladder cancer is a common cancer worldwide. Currently, the modality of treating and monitoring bladder cancer is wide. Nonetheless, the high recurrence rate of non-muscle-invasive bladder cancer after surgical resection is still unsatisfactory. Hereby, our study demonstrated whether the intra-operative and post-operative environments will affect bladder cancer recurrence utilizing in vitro cell line model. Bladder cancer cell lines were submerged in four different irrigating fluids for assessing their tumorigenic properties. Our results showed that sterile water performed the best in terms of the magnitude of cytotoxicity to cell lines. Besides, we also investigated cytotoxic effects of the four irrigating agents as well as mitomycin C (MMC) in normothermic and hyperthermic conditions. We observed that sterile water and MMC had an increased cytotoxic effect to bladder cancer cell lines in hyperthermic conditions. Altogether, our results could be translated into clinical practice in the future by manipulating the intra-operative and post-operative conditions in order to lower the chance of residual cancer cells reimplant onto the bladder, which in turns, reducing the recurrence rate of bladder cancers.

Background Bladder cancer (CaB) has a high recurrence rate despite surgery. As bladder is constantly filled with urine, it is worthwhile to investigate whether it could have any detrimental effects on bladder cancer cells. Methods We investigated the cytotoxicity of urine samples from CaB patients and normal controls on four CaB cell lines and tested the percentage of cell death, proliferation, adhesion, invasion and colonies formation ability. In order to identify the potential components involving in urine cytotoxicity, we evaluated some basic physiochemical parameters of urines, such as pH, osmolarity, creatinine (Cr), sodium (Na), potassium (K), chloride (Cl), calcium (Ca) and phosphate (PO4). We further compared the pH values of urine samples between CaB who developed recurrence versus those who did not. A more in-depth analysis on inflammatory markers was performed for two representative urine samples which demonstrated opposite cytoxic effects. Results 23 CaB patients and 20 normal controls were recruited into this study. According to in vitro experiments, both CaB and non-CaB urines had comparable effect on cell toxicity, proliferation, adhesion, invasion and colonies formation ability in four cell lines, HTB9, RT4, T24 and UMUC3, while RT4 was the most sensitive to urine toxicity. After evaluating the relationship between basic physiochemical parameters and cytotoxicity, we found out that there were strong negative correlations between pH value and 24 hours death rate for the 4 CaB cell lines (HTB9 r = -0.6651, p4 all had weakly or moderately positive correlations with CaB cells on 24 hours death rate. CaB patients who developed recurrence had more alkaline urine than those who did not develop recurrence. In the urine sample with the highest cytoxicity, high concentrations of IL-6 and IFN-gamma were found. Conclusions Our study confirmed that there was not statistically significant difference in cytotoxicity between CaB and non-CaB urines. However, we identified some parameters that could have an impact on cytotoxicity towards CaB cells. Modifying certain urine characteristics peri-operatively may induce cytotoxicity, avoid tumour re-implantation, and reduce the chance of cancer recurrence.

Prostate cancer is the most inheritable cancer with approximately 42% of disease risk attributed to inherited factors by studies of twins, indicating the importance of additional genetic screening to identify predisposition variants. However, only DNA damage repair (DDR) genes have been investigated thoroughly in prostate cancer. To determine the comprehensive germline mutation landscape in Chinese prostate cancer patients, we performed whole exome sequencing in 100 Han Chinese patients with prostate cancer in Hong Kong and identified deleterious germline mutations. A total of 36 deleterious germline variants in 25 genes were identified in 29% patients. Variants were found in eight pathways, including DNA methylation, DDR, and tyrosine-protein kinase. These findings were validated in an independent Chinese cohort of 167 patients with prostate cancer in Shanghai. Seven common deleterious-variant-containing genes were found in discovery cohort (7/25, 28%) and validation cohort (7/28, 25%) with three genes not described before (LDLR, MYH7 and SUGCT) and four genes previously reported (FANCI, ITGA6, PABPC1 and RAD54B). When comparing with that of a cohort of East Asian healthy individuals, 12 non-DDR novel potential predisposition genes (ADGRG1, CHD4, DNMT3A, ERBB3, GRHL1, HMBS, LDLR, MYH7, MYO6, NT5C2, NUP98 and SUGCT) were identified using the discovery and validation cohorts, which have not been previously reported in prostate cancer patients in all ethnic groups. Taken together, this study reveals a comprehensive germline mutation landscape in Chinese prostate cancer patients and discovers 12 novel non-DDR predisposition genes to lay the groundwork for the optimization of genetic screening.

Polyamines are essential biomolecules for normal cellular metabolism in humans. The roles of polyamines in cancer development have been widely discussed in recent years. Among all, spermine alongside with its acetylated derivative, N1, N12-Diacetylspermine, demonstrate a relationship with the diagnosis and staging of various cancers, including lung, breast, liver, colorectal and urogenital. Numerous studies have reported the level of spermine in different body fluids and organ tissues in patients with different types of cancers. Currently, the role and the underlying mechanisms of spermine in cancer development and progression are still under investigation. This review summarized the roles of spermine in cancer development and as a diagnostic, prognostic and therapeutic tool in various cancers.