Deubiquitinating enzyme OTUD4 stabilizes RBM47 to induce ATF3 transcription: a novel mechanism underlying the restrained malignant properties of ccRCC cells.

Dysregulation of deubiquitination contributes to various diseases, including cancer, and aberrant expression of deubiquitinating enzymes is involved in carcinoma progression. As a member of the ovarian tumor (OTU) deubiquitinases, OTUD4 is considered a tumor suppressor in many kinds of malignancies. The biological characteristics and mechanisms of OTUD4 in clear cell renal cell carcinoma (ccRCC) remain unclear. The downregulation of OTUD4 in ccRCC was confirmed based on the TCGA database and a validation cohort of 30-paired ccRCC and para-carcinoma samples. Moreover, OTUD4 expression was detected by immunohistochemistry in 50 cases of ccRCC tissues, and patients with lower levels of OTUD4 showed larger tumor size (p = 0.015). TCGA data revealed that patients with high expression of OTUD4 had a longer overall survival rate. In vitro and in vivo studies revealed that downregulation of OTUD4 was essential for tumor cell growth and metastasis in ccRCC, and OTUD4 overexpression inhibited these malignant phenotypes. We further found that OTUD4 sensitized ccRCC cells to Erastin-induced ferroptosis, and ferrostain-1 inhibited OTUD4-induced ferroptotic cell death. Mechanistic studies indicated that OTUD4 functioned as an anti-proliferative and anti-metastasic factor through the regulation of RNA-binding protein 47 (RBM47)-mediated activating transcription factor 3 (ATF3). OTUD4 directly interacted with RBM47 and promoted its stability via deubiquitination events. RBM47 was critical in ccRCC progression by regulating ATF3 mRNA stability, thereby promoting ATF3-mediated ferroptosis. RBM47 interference abolished the suppressive role of OTUD4 overexpression in ccRCC. Our findings provide mechanistic insight into OTUD4 of ccRCC progression and indicate a novel critical pathway OTUD4/RBM47/ATF3 may serve as a potential therapeutic pathway for ccRCC.

Biotransformation of antioxidant eriocitrin into characteristic metabolites by the gut microbiota.

Eriocitrin is a flavonoid glycoside with strong antioxidant capacity that has a variety of pharmacological activities, such as hypolipidemic, anticancer and anti-inflammatory effects. We found that the gut microbiota could rapidly metabolize eriocitrin. By using LC/MSn-IT-TOF, we identified three metabolites of eriocitrin metabolized in the intestinal microbiota: eriodictyol-7-O-glucoside, eriodictyol, and dihydrocaffeic acid. By comparing these two metabolic pathways of eriocitrin (the gut microbiota and liver microsomes), the intestinal microbiota may be the primary metabolic site of eriocitrin metabolism. These findings provide a theoretical foundation for the study of pharmacologically active substances.

Gut microbiota-derived metabolites in inflammatory diseases based on targeted metabolomics.

The gut microbiota plays an important role in inflammatory diseases. Metabolites in the three metabolic pathways of tryptophan (Trp), histidine (His), and phenylalanine (Phe) can affect various inflammatory conditions, such as obesity, diabetes, arthritis, colitis, atherosclerosis, and neuroinflammation. We established an LC-MS/MS method to measure 17 metabolites-Trp, 3-indole-acetic acid (Iaa), 3-indole-lactate (Ila), 3-indole-propionic acid (Ipa), 3-indole formaldehyde (Iald), kynurenine (Kn), kynurenic acid (Kyna), 3-Hydroxyanthranilic acid (3-Haa), His, 3-methylhistidine (3-Mhis), histamine (Hist), imidazole propionic acid (Imp), 4-imidazoacetic acid (Imaa), urocanic acid (Ua), Phe, phenylethylamine (Pea), and hippuric acid (Ha)-in the three metabolic pathways. The method exhibited high sensitivity and good selectivity, linearity, accuracy, precision, stability; and recovery rate; all met the requirements of biological sample analysis. By establishing a rheumatoid arthritis (RA) model of Sprague-Dawley rats and performing 16S rRNA sequencing on their feces, it was found that there was dysbiosis, including changes in phylum level, genus level, and α biodiversity of gut bacteria. The contents of the microbiota metabolites Iaa and Ipa in the model group were significantly decreased, and those of Iald, Kn, Kyna, Ha, and Imp were significantly increased. The common therapeutic drugs Tripterygium glycosides, total glucosides of peony, and their main active ingredients were screened by in vitro incubation with gut bacteria: it was found that Tripterygium glycosides and their active ingredients could lead to a variation in metabolites in the Trp and Phe pathways. Total glucosides and active components of peony could lead to a variation in metabolites in the Phe pathway of the gut microbiota.

Biotransformation of Abiraterone Into Five Characteristic Metabolites by the Rat Gut Microbiota and Liver Microsomes.

It is well known that the role of gut microbiota in drug metabolism, especially in oral difficult absorbable drugs. Understanding the gut microbiota could enable us to understand drugs in new ways. The purpose of the study was to investigate explore the metabolites of the anti-prostate cancer drug Abiraterone by examining gut microbiota metabolism and hepatic metabolism in vitro. In this study, five metabolites (M1, M2, M3, M4 and M5) of Abiraterone were discovered using LC/MSn-IT-TOF. Four isomeric metabolites M1-M4 were found in liver microsome. M5 was found in the intestinal contents of Sprague-Dawley rats with a molecular weight of 388.31. Among them, M4 was found to be Abiraterone N-Oxide by comparison with the standard sample. After further comparing the metabolic behavior of Abiraterone in rat gut microbiota and liver microsomes, we delineated the possible metabolic pathways of Abiraterone. In conclusion, Abiraterone is metabolized specifically in liver microsomes and gut microbiota. This study can provide a theoretical basis for elucidating the metabolic mechanism of Abiraterone and guide its rational application in clinic.

Biotransformation of Liquiritigenin into Characteristic Metabolites by the Gut Microbiota.

The bioavailability of flavonoids is generally low after oral administration. The metabolic transformation of flavonoids by the gut microbiota may be one of the main reasons for this, although these metabolites have potential pharmacological activities. Liquiritigenin is an important dihydroflavonoid compound found in Glycyrrhiza uralensis that has a wide range of pharmacological properties, such as antitumor, antiulcer, anti-inflammatory, and anti-AIDS effects, but its mechanism of action remains unclear. This study explored the metabolites of liquiritigenin by examining gut microbiota metabolism and hepatic metabolism in vitro. Using LC-MS/MS and LC/MSn-IT-TOF techniques, three possible metabolites of liquiritigenin metabolized by the gut microbiota were identified: phloretic acid (M3), resorcinol (M4), and M5. M5 is speculated to be davidigenin, which has antitumor activity. By comparing these two metabolic pathways of liquiritigenin (the gut microbiota and liver microsomes), this study revealed that there are three main metabolites of liquiritigenin generated by intestinal bacteria, which provides a theoretical basis for the study of pharmacologically active substances in vivo.

The potential biological effects of quercetin based on pharmacokinetics and multi-targeted mechanism in vivo.

Quercetin is a plant-derived polyphenol flavonoid that has been proven to be effective for many diseases. However, the mechanism and in vivo metabolism of quercetin remains to be clarified. It achieves a wide range of biological effects through various metabolites, gut microbiota and its metabolites, systemic mediators produced by inflammation and oxidation, as well as by multiple mechanisms. The all-round disease treatment of quercetin is achieved through the organic combination of multiple channels. Therefore, this article clarifies the metabolic process of quercetin in the body, and explores the new pattern of action of quercetin in the treatment of diseases.

Feasibility of single position laparoscopic radical nephrectomy and tumor thrombectomy for left renal cell carcinoma with high-risk Mayo grade 0 and 1 tumor thrombus.

BACKGROUND: To explore the feasibility of single-position laparoscopic radical nephrectomy (LRN) and tumor thrombectomy for left renal cell carcinoma with high-risk Mayo 0 and 1 tumor thrombus (TT). METHODS: All patients with left renal cell carcinoma and venous TT (high-risk Mayo grade 0 and 1) who were performed single-position LRN and tumor thrombectomy were involved. After the renal artery was controlled by Hem-o-lok, the left renal vein was dissected through descending colon mesentery. The left renal vein was divided by EndoGIA for high-risk Mayo grade 0 TT. For Mayo grade 1 TT, part of the inferior vena cava was blocked by a bulldog clamp after milking the TT into the left renal vein and the inferior vena cava was sutured after complete excision of the TT. RESULTS: 3 patients were involved and operations were performed successfully without conversion to open surgery. The mean operation time was 136 min and the mean estimated blood loss was 60 mL. No postoperative complications occurred. CONCLUSIONS: It is feasible to control left renal vein and partial inferior vena cava through descending colon mesentery in a single position during LRN and tumor thrombectomy for the treatment of high-risk Mayo grade 0 and 1 TT.

The circRAB3IP Mediated by eIF4A3 and LEF1 Contributes to Enzalutamide Resistance in Prostate Cancer by Targeting miR-133a-3p/miR-133b/SGK1 Pathway.

An increasing number of studies have shown that circRNAs are closely related to the carcinogenesis and development of prostate cancer (PCa). However, little is known about the effect of the biological functions of circRNAs on the enzalutamide resistance of PCa. Through bioinformatic analysis and experiments, we investigated the expression pattern of circRNAs in enzalutamide-resistant PCa cells. Quantitative real-time PCR was used to detect the expression of circRAB3IP, and plasmids that knock down or overexpress circRAB3IP were used to evaluate its effect on the enzalutamide sensitivity of PCa cells. Mechanistically, we explored the potential regulatory effects of eIF4A3 and LEF1 on the biogenesis of circRAB3IP. Our in vivo and in vitro data indicated that increased expression of circRAB3IP was found in enzalutamide-resistant PCa, and knockdown of circRAB3IP significantly enhanced enzalutamide sensitivity in PCa cells. However, upregulation of circRAB3IP resulted in the opposite effects. Further mechanistic research demonstrated that circRAB3IP could regulate the expression of serum and glucocorticoid-regulated kinase 1 (SGK1) by serving as a sponge that directly targets miR-133a-3p/miR-133b. Then, we showed that circRAB3IP partially exerted its biological functions via SGK1 signaling. Furthermore, we discovered that eIF4A3 and LEF1 might increase circRAB3IP expression in PCa.

Biotransformation of Timosaponin BII into Seven Characteristic Metabolites by the Gut Microbiota.

Timosaponin BII is one of the most abundant Anemarrhena saponins and is in a phase II clinical trial for the treatment of dementia. However, the pharmacological activity of timosaponin BII does not match its low bioavailability. In this study, we aimed to determine the effects of gut microbiota on timosaponin BII metabolism. We found that intestinal flora had a strong metabolic effect on timosaponin BII by HPLC-MS/MS. At the same time, seven potential metabolites (M1-M7) produced by rat intestinal flora were identified using HPLC/MS-Q-TOF. Among them, three structures identified are reported in gut microbiota for the first time. A comparison of rat liver homogenate and a rat liver microsome incubation system revealed that the metabolic behavior of timosaponin BII was unique to the gut microbiota system. Finally, a quantitative method for the three representative metabolites was established by HPLC-MS/MS, and the temporal relationship among the metabolites was initially clarified. In summary, it is suggested that the metabolic characteristics of gut microbiota may be an important indicator of the pharmacological activity of timosaponin BII, which can be applied to guide its application and clinical use in the future.

A negative-doughnut distal resection margin less than 5 mm does not affect prognosis in rectal cancer.

AIM: Many issues relating to the distal margin of anterior resection of the rectum still exist. We aimed to investigate whether negative distal resection margin (DRM) and positive DRM in the main specimen with negative doughnut has equivalent prognosis in patients with rectal cancer. METHODS: We included 287 patients with rectal cancer, including 69 cases with positive margins and 218 cases with negative margins, all of whom underwent regular follow-up. Survival rate was calculated using Kaplan-Meier survival analysis, while the log-rank test was used to determine statistical difference. Prognostic factors were found using the Cox regression model. RESULTS: There was no significant difference in clinicopathological features between the two groups with the exception of tumor location. Positive findings in the DRM with negative findings in the doughnut resection do not affect the overall survival, local recurrence, or distant metastasis. Factors relating to resection margin, such as the length of resection, negative, or positive findings, were not found to be prognostic. CONCLUSION: Given postoperative pathology results with positive DRM but negative findings in the doughnut resection, a second surgery was not necessary. Instead, adjuvant radiochemotherapy and close follow-up will suffice.

Temporary Diverting Stoma Improves Recovery of Anastomotic Leakage after Anterior Resection for Rectal Cancer.

Temporary diverting stoma might be a protective factor for the prevention of anastomotic leakage (AL) after anterior resection. Its role in leakage recovery is unknown. This study aimed to evaluate the effect of temporary diverting stoma on anastomotic leakage severity and recovery. We analyzed 323 patients who underwent anterior resection for rectal cancer and developed anastomotic leakage, in which 44 had temporary diverting stoma. Association between diverting stoma and occurrence of anastomotic leakage, recovery time, length of hospital stay, overall costs, local and distant relapse-free survival were further studied. In non-severe AL group, temporary diverting stoma improved leakage recovery by 4 days (mean: 20.7 days vs. 16.1 days, p = 0.031), especially in patients who did not receive neoadjuvant treatment (mean time: 20.9 days vs. 14.4 days, p = 0.016). However, it did not delay the occurrence of anastomotic leakage. Moreover, no significant difference was found in the overall length of hospital stay and costs among patients with versus without a diverting stoma. In severe AL group, however, no difference was detected. The advantage of shortened leakage recovery did not reduce the local and distant relapse-free survival. In conclusion, our findings indicated the recovery benefit from diverting stoma in patients with anterior resection.

Comparative study of single-center patients with thyroid metastases from colorectal cancer and previously reported cases in the literature.

BACKGROUND: Thyroid metastases from colorectal cancer (CRC) are rare, both in clinical practice and in the literature; hence, their diagnosis, appropriate treatment, and prognostic factors require further investigations. METHODS: A retrospective analysis was performed for four cases of thyroid metastases from CRC, treated in our center between January 2005 and December 2015, and the relevant literature was searched using PubMed, resulting in the identification of 17 patients with detailed information available. The clinical data and follow-up information of our patients and the previously reported cases were collected and compared. RESULTS: The median age of the 21 patients was 59 years (44.5 and 66 years for our patients and the previously reported cases, respectively). Fifteen (71.4%) primary tumors were distributed throughout the distal colon or rectum (75% [3/4] in our center and 70.5% [12/17] in the previously reported cases). According to our analysis, we found that 81.0% of patients (17/21) showed concomitant lung metastasis. Among them, all four patients in our center showed lung metastasis, and 75% (3/4) developed thyroid metastases after the lung metastasis. In the previously reported cases, the corresponding proportions were 76.5 and 76.5% (13/17) of patients, respectively. The median time after primary tumor diagnosis to thyroid metastasis development was 28 months (26 months in our center and 35 months in the previously reported cases). One patient with advanced CRC in our center died 5 months after the thyroid metastasis was identified, while the remaining three patients are currently alive (longest follow-up time, 27 months). The median survival time after thyroid metastasis during 3 years of follow-up of the previously reported 17 patients was 12 months. There was no difference in the overall survival between patients treated non-surgically (8/21) and patients undergoing thyroidectomy alone or thyroidectomy with adjuvant therapy (13/21) (p = 0.388). In addition, we found that the overall survival of the patients whose other metastases were treated with radical treatment was superior to that in those treated with palliative treatment (p = 0.022). CONCLUSIONS: Thyroid metastases from CRC are rare in clinical practice and are a manifestation of advanced CRC. The prognosis of patients with thyroid metastases from CRC is related to various factors, including the grade of malignancy of the primary lesion, the presence of other metastases, and whether the metastases are timely diagnosed and a radical treatment strategy is employed.

CapOX as neoadjuvant chemotherapy for locally advanced operable colon cancer patients: a prospective single-arm phase II trial.

OBJECTIVE: The aim of this prospective, single-arm phase II trial was to confirm the safety and efficacy of neoadjuvant chemotherapy (NAC) using oxaliplatin plus capecitabine (CapOX) for patients with operable locally advanced colon cancer (CC). METHODS: Patients with computed tomography-defined T4 or lymph node-positive CCs were enrolled. After radiological staging, patients were treated with at least 2 cycles of NAC consisting of 130 mg/m2 oxaliplatin on d 1, plus 1,000 mg/m2 capecitabine twice daily for 14 d every 3 weeks, followed by surgery, and then with the rest cycles of adjuvant chemotherapy. Radiological response was evaluated after 2 cycles of NAC. Tumor response, treatment toxicity, and surgical complications were recorded. The pathological response to therapy was evaluated according to the tumor regression grade (TRG) score. The primary endpoint was pathologic tumor response. This trial is registered in ClinicalTrials.gov (No: NCT02415829). RESULTS: Forty-seven patients were enrolled in the study. Forty-two patients completed the planned treatments. The total radiological response rate was 68% (32/47), including complete and partial response rates of 2% (1/47) and 66% (31/47), respectively. Stable disease was observed in 32% (15/47) and progressive disease was observed in none. Complete pathologic response, major regression, and at least moderate regression were achieved in 1 (2%), 2 (4%), and 29 (62%) patients, respectively. Four patients developed grade 3 treatment toxicities. One patient with wound infection occurred after operation (1/47, 2%). There was no treatment-related death. CONCLUSIONS: Our results suggest that NAC with CapOX is an effective and safe treatment option for patients with locally advanced CCs.