Limited carbon source retards inorganic arsenic release during roxarsone degradation in Shewanella oneidensis microbial fuel cells.

Directly relevant to the toxicity, mobility, and fate of arsenic, the biotransformation of inorganic and organic arsenicals has been extensively concerned, including roxarsone, a widely applied organoarsenical feed additive in poultry industry. Yet, little is known about the transformation details of roxarsone in microbial fuel cells (MFC). In this study, a two-chambered Shewanella oneidensis MR-1 microbial fuel cell was employed to investigate the transformation processes of roxarsone at various carbon source levels. Results show that limited carbon source remarkably inhibited inorganic arsenic release along roxarsone transformation, whereas numerous arsenical species were detected to be released into systems with sufficient carbon source supply, including trivalent and pentavalent inorganic arsenics, monomethylarsonous acid (MMA), and 4-hydroxy-3-aminobenzene arsonic acid (HAPA). Shewanella oneidensis MR-1 was able to cleave the C-As bond of trivalent HAPA yielding inorganic arsenics and MMA, even in the absence of the arsI gene encoding ArsI C-As lyase. We proposed a two-step nitro- and pentavalent-arsenate group reduction pathway for the roxarsone bioelectrochemical transformation. In addition, results indicated that the attached cells onto the electrode surface played a key function in the two-step reduction of roxarsone to trivalent HAPA, whereas planktonic cells were most likely responsible for the C-As bond breakage and the following dearylation. With these qualitative and quantitative estimations, it provides new insights into the mechanistic understanding of the roxarsone biotransformation process in microbial fuel cells, which is important for the biogeochemical cycling of arsenic.

Upregulation of FGD6 Predicts Poor Prognosis in Gastric Cancer.

Background: The aim of this study was to investigate the prognostic significance of faciogenital dysplasia 6 (FGD6) in gastric cancer (GC). Methods: The data of GC patients from The Cancer Genome Atlas (TCGA) database were used for the primary study. Then, our data were validated by the GEO database and RuiJin cohort. The relationship between the FGD6 level and various clinicopathological features was analyzed by logistic regression and univariate Cox regression. Multivariate Cox regression analysis was used to evaluate whether FGD6 was an independent prognostic factor for survival of patients with GC. The relationship between FGD6 and overall survival time was explored by the Kaplan-Meier method. In addition, gene set enrichment analysis (GSEA) was performed to investigate the possible biological processes of FGD6. Results: The FGD6 level was significantly overexpressed in GC tissues, compared with adjacent normal tissues. The high expression of FGD6 was related to a high histological grade, stage, and T classification and poor prognosis of GC. Multivariate Cox regression analysis showed that FGD6 was an independent prognostic factor for survival of patients with GC. GSEA identified that the high expression of FGD6 was mainly enriched in regulation of actin cytoskeleton. Conclusion: FGD6 may be a prognostic biomarker for predicting the outcome of patients with GC.

A Hepatocellular Carcinoma Patient with TSC1 Mutations Benefits from Treatment with Everolimus: A Case Report.

Hepatocellular carcinoma (HCC) has a high degree of malignancy and poor prognosis. Treatment options for patients with advanced HCC are limited. There is currently no evidence to approve the accumulation of targeted therapies for HCC to support the inhibition of the PI3K/Akt/mTOR signaling pathway as an effective therapeutic strategy. We report on a patient with advanced HCC carrying the TSC1 gene mutation who responded well to the mammalian target of rapamycin inhibitor everolimus. Computed tomography revealed tumor shrinkage and maintenance of partial remission after everolimus treatment for >12.3 months. To the best of our knowledge, this is the first clinical case report showing benefit from everolimus treatment in HCC patients with TSC1 gene mutations. Therefore, everolimus may be used as a potential targeted therapy for HCC with TSC1 gene mutation.

Mutation profile and its correlation with clinicopathology in Chinese hepatocellular carcinoma patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common causes of cancer worldwide. Although many studies have focused on oncogene characteristics, the genomic landscape of Chinese HCC patients has not been fully clarified. METHODS: A total of 165 HCC patients, including 146 males and 19 females, were enrolled. The median age was 55 years (range, 27-78 years). Corresponding clinical and pathological information was collected for further analysis. A total of 168 tumor tissues from these patients were selected for next-generation sequencing (NGS)-based 450 panel gene sequencing. Genomic alterations including single nucleotide variations (SNV), short and long insertions and deletions (InDels), copy number variations, and gene rearrangements were analyzed. Tumor mutational burden (TMB) was measured by an algorithm developed in-house. The top quartile of HCC was classified as TMB high. RESULTS: A total of 1,004 genomic alterations were detected from 258 genes in 168 HCC tissues. TMB values were identified in 160 HCC specimens, with a median TMB of 5.4 Muts/Mb (range, 0-28.4 Muts/Mb) and a 75% TMB of 7.7 Muts/Mb. The most commonly mutated genes were TP53, TERT, CTNNB1, AXIN1, RB1, TSC2, CCND1, ARID1A, and FGF19. SNV was the most common mutation type and C:G>T:A and guanine transformation were the most common SNVs. Compared to wild-type patients, the proportion of Edmondson grade III-IV and microvascular invasion was significantly higher in TP53 mutated patients (P<0.05). The proportion of tumors invading the hepatic capsule was significantly higher in TERT mutated patients (P<0.05). The proportion of Edmondson grade I-II, alpha fetoprotein (AFP) <25 µmg/L, and those without a history of hepatitis B was significantly higher in CTNNB1 mutated patients (P<0.05). CTNNB1 mutations were associated with TMB high in HCC patients (P<0.05). Based on correlation analysis, the mutation of TP53 was independently correlated with microvascular invasion (P=0.002, OR =3.096) and Edmondson grade III-IV (P=0.008, OR =2.613). The mutation of TERT was independently correlated with tumor invasion of the liver capsule (P=0.001, OR =3.030), and the mutation of CTNNB1 was independently correlated with AFP (<25 µmg/L) (P=0.009, OR =3.414). CONCLUSIONS: The most frequently mutated genes of HCC patients in China were TP53, TERT, and CTNNB1, which mainly lead to the occurrence and development of HCC by regulating the P53 pathway, Wnt pathway, and telomere repair pathway. There were more patients with microvascular invasion and Edmondson III-IV grade in TP53 mutated patients and more patients with hepatic capsule invasion in TERT mutated patients, while in CTNNB1 mutated patients, there were more patients with Edmondson I-II grade, AFP <25 µmg/L, and a non-hepatitis B background. Also, the TMB values were significantly higher in CTNNB1 mutated patients than in wild type patients.