Targeting UBE2T Potentiates Gemcitabine Efficacy in Pancreatic Cancer by Regulating Pyrimidine Metabolism and Replication Stress.

BACKGROUND & AIMS: Although small patient subsets benefit from current targeted strategies or immunotherapy, gemcitabine remains the first-line drug for pancreatic cancer (PC) treatment. However, gemcitabine resistance is widespread and compromises long-term survival. Here, we identified ubiquitin-conjugating enzyme E2T (UBE2T) as a potential therapeutic target to combat gemcitabine resistance in PC. METHODS: Proteomics and metabolomics were combined to examine the effect of UBE2T on pyrimidine metabolism remodeling. Spontaneous PC mice (LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre; KPC) with Ube2t-conditional knockout, organoids, and large-scale clinical samples were used to determine the effect of UBE2T on gemcitabine efficacy. Organoids, patient-derived xenografts (PDX), and KPC mice were used to examine the efficacy of the combination of a UBE2T inhibitor and gemcitabine. RESULTS: Spontaneous PC mice with Ube2t deletion had a marked survival advantage after gemcitabine treatment, and UBE2T levels were positively correlated with gemcitabine resistance in clinical patients. Mechanistically, UBE2T catalyzes ring finger protein 1 (RING1)-mediated ubiquitination of p53 and relieves the transcriptional repression of ribonucleotide reductase subunits M1 and M2, resulting in unrestrained pyrimidine biosynthesis and alleviation of replication stress. Additionally, high-throughput compound library screening using organoids identified pentagalloylglucose (PGG) as a potent UBE2T inhibitor and gemcitabine sensitizer. The combination of gemcitabine and PGG diminished tumor growth in PDX models and prolonged long-term survival in spontaneous PC mice. CONCLUSIONS: Collectively, UBE2T-mediated p53 degradation confers PC gemcitabine resistance by promoting pyrimidine biosynthesis and alleviating replication stress. This study offers an opportunity to improve PC survival by targeting UBE2T and develop a promising gemcitabine sensitizer in clinical translation setting.

A novel protein encoded by circFNDC3B inhibits tumor progression and EMT through regulating Snail in colon cancer.

BACKGROUND: Colon cancer (CC) is a common malignant cancer. Recently, circFNDC3B was found to exert biological function in multiple cancers. However, it was unclear whether the potential protein encoded by circFNDC3B is involved in carcinogenesis of CC. METHODS: We used Sanger sequence and RNase R digestion assay to confirm the existence of circFNDC3B, and quantitative real-time PCR was used to evaluate the circRNA's expression. Then fluorescence in situ hybridization (FISH) was performed to study location of circFNDC3B. The identification of protein encoded by circFNDC3B was performed using LC-MS/MS. The function of circFNDC3B-218aa on proliferation, invasion and migration were assessed by CCK8 assays, colony formation assays, transwell assays, wound-healing assays and animal experiments. RNA-sequencing and western blot were used to identify the gene regulated by circFNDC3B-218aa. Finally, glucose metabolism-related assays were performed to further investigate function of circFNDC3B-218aa. RESULTS: CircFNDC3B was localized mostly in the cytoplasm, and was decreased in CC cell lines and tissues. The patients with low circFNDC3B expression had a shorter OS (P = 0.0014) than patients with high expression. Moreover, circFNDC3B inhibited the proliferation, invasion and migration of CC cells. Next, we identified that circFNDC3B could encode a novel protein circFNDC3B-218aa. Furthermore, circFNDC3B-218aa, not circFNDC3B, inhibited the proliferation, invasion and migration of CC. Additionally, the in vivo experiments implied that up-regulated circFNDC3B-218aa exhibited an inhibitory effect on CC progression. By RNA-sequencing, western blot and glucose metabolism-related assays, we found that circFNDC3B-218aa inhibited the expression of Snail, and subsequently promoted the tumor-suppressive effect of FBP1 in CC. CONCLUSIONS: The novel circFNDC3B-218aa may serve as a tumor suppressive factor and potential biomarker which may supply the potential therapeutic target for CC.

Random-forest algorithm based biomarkers in predicting prognosis in the patients with hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) one of the most common digestive system tumors, threatens the tens of thousands of people with high morbidity and mortality world widely. The purpose of our study was to investigate the related genes of HCC and discover their potential abilities to predict the prognosis of the patients. METHODS: We obtained RNA sequencing data of HCC from The Cancer Genome Atlas (TCGA) database and performed analysis on protein coding genes. Differentially expressed genes (DEGs) were selected. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were conducted to discover biological functions of DEGs. Protein and protein interaction (PPI) was performed to investigate hub genes. In addition, a method of supervised machine learning, recursive feature elimination (RFE) based on random forest (RF) classifier, was used to screen for significant biomarkers. And the basic experiment was conducted by lab, we constructe a clinical patients' database, and obtained the data and results of immunohistochemistry. RESULTS: We identified five biomarkers with significantly high expression to predict survival risk of the HCC patients. These prognostic biomarkers included SPC25, NUF2, MCM2, BLM and AURKA. We also defined a risk score model with these biomarkers to identify the patients who is in high risk. In our single-center experiment, 95 pairs of clinical samples were used to explore the expression levels of NUF2 and BLM in HCC. Immunohistochemical staining results showed that NUF2 and BLM were significantly up-regulated in immunohistochemical staining. High expression levels of NUF2 and BLM indicated poor prognosis. CONCLUSION: Our investigation provided novel prognostic biomarkers and model in HCC and aimed to improve the understanding of HCC. In the results obtained, we also conducted a part of experiments to verify the theory described earlier, The experimental results did verify our theory.

Pancreatic fistula after pancreatoduodenectomy due to compression of the superior mesenteric vessels: a case report.

BACKGROUND: Pancreatic fistula is a common complication after pancreaticoduodenectomy, which could be caused by: soft pancreatic tissue, pancreatic duct diameter < 3 mm and body mass index ≥25 kg/m2. Here we report a case of pancreatic fistula due to obstruction of the jejunal loop due to compression of the jejunal loop by the superior mesenteric vessels. CASE PRESENTATION: A 68-year-old man was admitted to our ward due to intermittent epigastric distension and pain. After various examinations and treatments, he was diagnosed with middle bile duct cancer. Pancreaticoduodenectomy was performed, and pancreaticojejunostomy and hepaticojejunostomy were completed by lifting the jejunal loop from behind the superior mesenteric vessels to the upper region of the colon. On postoperative day 9, the patient developed acute diffuse peritonitis, and on postoperative day 10, the patient underwent a second exploratory laparotomy, during which it was confirmed that the pancreatic fistula was caused by obstruction of the jejunal loop due to compression of the jejunal loop by the superior mesenteric vessels, then the patient recovered and was discharged alive after retrograde drainage in the jejunum. CONCLUSIONS: The superior mesenteric vessels after pancreaticoduodenal surgery can compress the jejunal loop and cause obstruction leading to serious complications, and it is recommended that general surgeons should avoid lifting the jejunal loop from the posterior aspect of the superior mesenteric vessels to complete the anastomosis.

Duodenal Bulb Adenocarcinoma Benefitted from Neoadjuvant Chemotherapy: A Case Report.

Duodenal bulb adenocarcinoma is an extremely rare malignancy in the alimentary tract which has a low incidence rate and nonspecific symptoms. It is difficult to diagnose early, and the misdiagnosis rate is high. CT, MRI, upper gastrointestinal endoscopy, and other advanced imaging modalities should be combined to make a comprehensive evaluation. The diagnostic confirmation of this tumor type mainly depends on the pathological examination. The combination of surgery with other treatment modalities is effective. A review of reports on duodenal bulb adenocarcinoma with chemotherapy revealed 6 cases since 1990. However, there are few reports on neoadjuvant chemotherapy for the disease. In this report, preoperative S-1 in combination with oxaliplatin neoadjuvant chemotherapy achieved a complete pathological response in the treatment of duodenal bulb adenocarcinoma. Neoadjuvant chemotherapy shows a better clinical efficacy in the treatment of duodenal bulb adenocarcinoma, but its value needs to be further verified.

[Clinical study on surgical method and prognosis in diffuse-type advanced gastric cancer].

OBJECTIVE: To explore the prognosis and surgical method for diffuse-type advanced gastric cancer (AGC).
 METHODS: The clinicopathological data of patient, who underwent curative gastrectomy in the Second Hospital Affiliated to Lanzhou University from 2005 to 2010, were analyzed retrospectively. The prognostic factors of diffuse-type AGC were analyzed by Cox regression models. The patients were divided into a total gastrectomy group (n=120) and a subtotal gastrectomy group (n=167) according to the surgical approach. Survival rates were established by the Kaplan-Meier method and compared by the Log-rank test between the total gastrectomy group and the subtotal gastrectomy group.
 RESULTS: A total of 287 patients with diffuse-type AGC were enrolled in this study, including 120 patients in the total gastrectomy group and 167 patients in the subtotal gastrectomy group. Univariate analysis showed that the prognosis of diffuse-type AGC was associated with body mass index, number of retrieved lymph nodes, Borrmann type, tumor size, T stage, N stage, tumor-node-metastasis (TNM) stage, extent of resection, surgical margin, postoperative complication, perineural and vascular invasion (all P<0.01). Multivariate analysis showed that normal body mass index, tumor size, T stage, N stage, total gastrectomy, surgical margin, postoperative complication were the independent predictors for diffuse-type AGC (all P<0.05). The 5-year overall survival rate and progression-free survival rate for diffuse-type AGC after curative gastrectomy were 17.8% and 13.6%, respectively. The median survival time and progression-free survival of them were 22 and 18 months, respectively. The overall survival rate and progression-free survival rate in the total gastrectomy group was significantly higher than that in the subtotal gastrectomy (P<0.01); the extended extent of lymph node dissection, the lower rate of positive surgical margin and postoperative complications were present in the total gastrectomy group (all P<0.05 or P<0.01).
 CONCLUSION: The patients with diffuse-type AGC have a poor prognosis. The great tumor diameter, advanced T stage, advanced N stage, subtotal gastrectomy, high rate of positive surgical margin and postoperative complication are independent risky factors for the diffuse-type AGC. However, the total gastrectomy may be beneficial to patients.

[Research progress of Lauren classification for gastric cancer].

Gastric cancer (GC) is one of the most common malignant tumors with high heterogeneity. According to Lauren classification, GC is divided into intestinal type and diffuse type. With rapid progress in technologies and ideas in the clinical diagnosis for GC, the normalized and individualized comprehensive treatment has become the main trend. However, the clinicopathological characteristics, remedy and prognosis for GC may be different because of the different classifications and stages.

Single-port retroperitoneoscopic pancreatectomy: preliminary results from the first 3 patients.

To date, single-port laparoscopic pancreatic surgery has been rarely reported. This study aimed to evaluate the feasibility and safety of single-port retroperitoneoscopic pancreatectomy based on the first 3 cases in a single center. Three patients with suspected lesions in the distal pancreas underwent single-port retroperitoneoscopic pancreatectomy using a conventional retroperitoneoscopic pancreatectomy approach. All operations were successfully completed utilizing a single port. Operating times were 50, 90, and 150 minutes for the 3 cases. There were no complications, and all patients were discharged within 7 days after surgery. In conclusion, for selected patients, single-port retroperitoneoscopy can be safely utilized for pancreatectomy.

Two anatomical pathways for retroperitoneoscopic pancreatectomy: indications for the posterior and lateral approaches.

BACKGROUND: Retroperitoneoscopic pancreatectomy (RP) is a novel surgical procedure that is safe and feasible in animal models and clinical practice. However, the optimal approach for RP has not been established. OBJECTIVE: This study aimed to introduce the posterior and lateral approaches for RP. METHODS: This prospective study included 19 patients with suspected pancreatic lesions who underwent RP. RP was performed using either a posterior or a lateral approach. RESULTS: The posterior, lateral, and jointed approaches were used in 13 (68.4 %), 3 (15.8 %), and 3 (15.8 %) cases, respectively. Patients underwent enucleation (N = 8), distal pancreatectomy (N = 4), and resection of cystic pancreatic lesions (N = 2) and non-pancreatic lesions (N = 5). All retroperitoneoscopic procedures were successfully accomplished with no conversion to open or laparoscopic surgery. Intraoperative complications occurred in two (12.5 %) cases, including one case with injury to the peritoneum and one case with injury to the peritoneum and splenic vein. Postoperative grade A pancreatic fistulas occurred in six cases, and were cured by delayed drainage. No disease recurrence or abnormal symptoms were observed during the mean follow-up period of 14.06 ± 9.60 months. CONCLUSIONS: RP using the posterior or lateral approach is feasible and effective, but has different indications. The posterior approach is useful for distal pancreatectomy, as well as resection of pancreatic lesions in the posterior or superoposterior region of the distal pancreas. The lateral approach is useful for resection of pancreatic lesions in the anterior or inferior region of the body and tail. The two approaches can be used in combination or conversion.

[Laparoscopic cystogastrostomy with posterior approach for pancreatic pseudocyst drainage].

OBJECTIVE: To determine the clinical value of laparoscopic cystogastrostomy in the treatment of pancreatic pseudocyst. METHODS: Twenty-one patients with pancreatic pseudocyst received total laparoscopic cystogastrostomy. The data on intra-operative bleeding, operative time, post-operative time to get out of bed, time of first flatus/bowel motion, complication and duration of hospital stay were observed and analyzed retrospective1y. RESULTS: Twenty-one patients were successfully carried out the laparoscopic surgery. The average operation time was 90(62-120) min. The blood loss was less than 100 mL in all patients. The average time of hospital stay was 8 d. After 12-18 month follow-up, all patients recovered smoothly without any complication. CONCLUSION: Total laparoscopic cystogastrostomy with the posterior approach is a feasible, safe and minimal invasive procedure for pancreatic pseudocyst, which can be recommended to the clinical application.

PICH Activates Cyclin A1 Transcription to Drive S-Phase Progression and Chemoresistance in Gastric Cancer.

The chemotherapeutic agent 5-fluorouracil (5-FU) remains the backbone of postoperative adjuvant treatment for gastric cancer. However, fewer than half of patients with gastric cancer benefit from 5-FU-based chemotherapies owing to chemoresistance and limited clinical biomarkers. Here, we identified the SNF2 protein Polo-like kinase 1-interacting checkpoint helicase (PICH) as a predictor of 5-FU chemosensitivity and characterized a transcriptional function of PICH distinct from its role in chromosome separation. PICH formed a transcriptional complex with RNA polymerase II (Pol II) and ATF4 at the CCNA1 promoter in an ATPase-dependent manner. Binding of the PICH complex promoted cyclin A1 transcription and accelerated S-phase progression. Overexpressed PICH impaired 5-FU chemosensitivity in human organoids and patient-derived xenografts. Furthermore, elevated PICH expression was negatively correlated with survival in postoperative patients receiving 5-FU chemotherapy. Together, these findings reveal an ATPase-dependent transcriptional function of PICH that promotes cyclin A1 transcription to drive 5-FU chemoresistance, providing a potential predictive biomarker of 5-FU chemosensitivity for postoperative patients with gastric cancer and prompting further investigation into the transcriptional activity of PICH. SIGNIFICANCE: PICH binds Pol II and ATF4 in an ATPase-dependent manner to form a transcriptional complex that promotes cyclin A1 expression, accelerates S-phase progression, and impairs 5-FU chemosensitivity in gastric cancer.

Present and Future Prospects of the Anti-cancer Activities of Saikosaponins.

Since their discovery, saikosaponins (SSs) have been found to play an important role in treating a variety of cancers via diverse mechanisms of action. This review summarizes the current research status and prospects of the anti-cancer activities of SSs, providing novel insights into the limitations of current studies. In addition, it discusses whether SSs can be applied in immunotherapy and the possible mechanisms by which SSs may facilitate immunotherapy. The research is significant to understanding the anti-cancer potents of SSs in the development of SSs-based therapeutic strategies and clinical practice.

Therapeutic strategies targeting uPAR potentiate anti-PD-1 efficacy in diffuse-type gastric cancer.

The diffuse-type gastric cancer (DGC) is a subtype of gastric cancer (GC) associated with low HER2 positivity rate and insensitivity to chemotherapy and immune checkpoint inhibitors. Here, we identify urokinase-type plasminogen activator receptor (uPAR) as a potential therapeutic target for DGC. We have developed a novel anti-uPAR monoclonal antibody, which targets the domains II and III of uPAR and blocks the binding of urokinase-type plasminogen activator to uPAR. We show that the combination of anti-uPAR and anti-Programmed cell death protein 1 (PD-1) remarkably inhibits tumor growth and prolongs survival via multiple mechanisms, using cell line-derived xenograft and patient-derived xenograft mouse models. Furthermore, uPAR chimeric antigen receptor-expressing T cells based on the novel anti-uPAR effectively kill DGC patient-derived organoids and exhibit impressive survival benefit in the established mouse models, especially when combined with PD-1 blockade therapy. Our study provides a new possibility of DGC treatment by targeting uPAR in a unique manner.

A novel UBE2T inhibitor suppresses Wnt/ß-catenin signaling hyperactivation and gastric cancer progression by blocking RACK1 ubiquitination.

Dysregulation of the Wnt/ß-catenin signaling pathway is critically involved in gastric cancer (GC) progression. However, current Wnt pathway inhibitors being studied in preclinical or clinical settings for other cancers such as colorectal and pancreatic cancers are either too cytotoxic or insufficiently efficacious for GC. Thus, we screened new potent targets from ß-catenin destruction complex associated with GC progression from clinical samples, and found that scaffolding protein RACK1 deficiency plays a significant role in GC progression, but not APC, AXIN, and GSK3ß. Then, we identified its upstream regulator UBE2T which promotes GC progression via hyperactivating the Wnt/ß-catenin signaling pathway through the ubiquitination and degradation of RACK1 at the lysine K172, K225, and K257 residues independent of an E3 ligase. Indeed, UBE2T protein level is negatively associated with prognosis in GC patients, suggesting that UBE2T is a promising target for GC therapy. Furthermore, we identified a novel UBE2T inhibitor, M435-1279, and suggested that M435-1279 acts inhibit the Wnt/ß-catenin signaling pathway hyperactivation through blocking UBE2T-mediated degradation of RACK1, resulting in suppression of GC progression with lower cytotoxicity in the meantime. Overall, we found that increased UBE2T levels promote GC progression via the ubiquitination of RACK1 and identified a novel potent inhibitor providing a balance between growth inhibition and cytotoxicity as well, which offer a new opportunity for the specific GC patients with aberrant Wnt/ß-catenin signaling.

Hyperactivation of HER2-SHCBP1-PLK1 axis promotes tumor cell mitosis and impairs trastuzumab sensitivity to gastric cancer.

Trastuzumab is the backbone of HER2-directed gastric cancer therapy, but poor patient response due to insufficient cell sensitivity and drug resistance remains a clinical challenge. Here, we report that HER2 is involved in cell mitotic promotion for tumorigenesis by hyperactivating a crucial HER2-SHCBP1-PLK1 axis that drives trastuzumab sensitivity and is targeted therapeutically. SHCBP1 is an Shc1-binding protein but is detached from scaffold protein Shc1 following HER2 activation. Released SHCBP1 responds to HER2 cascade by translocating into the nucleus following Ser273 phosphorylation, and then contributing to cell mitosis regulation through binding with PLK1 to promote the phosphorylation of the mitotic interactor MISP. Meanwhile, Shc1 is recruited to HER2 for MAPK or PI3K pathways activation. Also, clinical evidence shows that increased SHCBP1 prognosticates a poor response of patients to trastuzumab therapy. Theaflavine-3, 3'-digallate (TFBG) is identified as an inhibitor of the SHCBP1-PLK1 interaction, which is a potential trastuzumab sensitizing agent and, in combination with trastuzumab, is highly efficacious in suppressing HER2-positive gastric cancer growth. These findings suggest an aberrant mitotic HER2-SHCBP1-PLK1 axis underlies trastuzumab sensitivity and offer a new strategy to combat gastric cancer.

Docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil (FLOT) as preoperative and postoperative chemotherapy compared with surgery followed by chemotherapy for patients with locally advanced gastric cancer: a propensity score-based analysis.

Introduction: Docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil (FLOT) may improve overall survival (OS) in patients with locally advanced gastric cancer (LAGC); however, evidence for its use as a standard treatment has not been established in China. The aim of this study was to investigate the effectiveness, safety, and feasibility of the FLOT regimen as neoadjuvant chemotherapy in Chinese patients with resectable LAGC. Methods: We conducted an observational study to compare the effectiveness of FLOT regimen consisting of docetaxel (60 mg/m2), oxaliplatin (85 mg/m2), leucovorin (200 mg/m2), and 5-fluorouracil (2,600 mg/m2 as a 24 hr infusion), all given on day 1 and administered every 2 weeks versus initial surgery followed by chemotherapy in patients with clinical T3-4 LAGC. OS was compared by using the Cox proportional hazards regression model and the Kaplan-Meier curve adjusted by inverse probability of treatment weighting (IPTW) and propensity score-matched (PSM) analysis. In addition, we performed subgroup analyses to determine the effectiveness of the FLOT regimen in clinically relevant patient subsets. Results: Overall, 47 patients who received initial FLOT chemotherapy and 269 patients who received initial surgery were enrolled in this study. In the PSM analysis, the FLOT-first group showed favorable OS compared with the surgery-first group (41 vs 41 [HR, 0.416; 95% CI, 0.218-0.794; P=0.008]), and 3-year survival rates were 58.7% and 30.9% in the FLOT-first group and surgery-first group, respectively. IPTW analysis showed similar results. However, the effect of FLOT was low (HR, 0.868; 95 CI%, 0.215-3.504) in patients without lymph node metastasis. Conclusion: Our study suggests that preoperative FLOT chemotherapy is safe and feasible. In terms of OS, FLOT may be superior to initial surgery followed by chemotherapy in reducing morbidity with resectable LAGC.

Clinical characteristics and prognostic significance of galectins for patients with gastric cancer: A meta-analysis.

OBJECTIVE: To explore the relationships between the expression level of different galectins and its prognostic value for patients with gastric cancer. METHODS: The PubMed, EMbase, the Cochrane Library and Web of Science databases were systematically searched. All the eligible studies were included according to the inclusion and exclusion criteria. All the relevant data was extracted by two independent researchers. The quality assessment was conducted according to the evaluation of the quality of prognosis study which published by Harden in 2006. The STATA 12.0 software was used to perform a meta-analysis. RESULTS: All of 8 retrospective case-controlled studies involving 2093 patients with gastric cancer were included in this study. The results of meta-analysis presented that the elevated galectin-1 which is related to the poor overall survival (HR = 1.85, 95% CI: 1.33-2.58; P < 0.001) may predicted a larger tumor size (OR = 2.20, 95% CI: 1.35-3.35; P = 0.001) and was positively associated with the higher expression of VEGF (OR = 1.44, 95% CI: 1.14-1.82; P = 0.002). Moreover, the decreased galectin-3 (HR = 0.49, 95% CI: 0.36-0.67; P < 0.001), galectin-8 (HR = 0.49, 95% CI: 0.36-0.67; P < 0.001) and galectin-9 (HR = 0.78, 95% CI: 0.66-0.92; P = 0.003) were also significantly associated with poorer prognosis. Our meta-analysis also showed that lower expression of galectin-3 was also related to lymphatic vessel invasion (OR = 0.48, 95% CI: 0.26-0.89; P = 0.018), worse TNM stages (OR = 0.47, 95% CI: 0.32-0.40; P < 0.001), deeper invasive depth (OR = 0.33, 95% CI: 0.21-0.51; P < 0.001) and poorer differentiation grade (OR = 0.10, 95% CI: 0.04-0.25; P < 0.001). CONCLUSIONS: High expression of galectin-1 or low expression of galectin-3, -8 and -9 were significantly related to a poorer prognosis for patients with gastric cancer. The expression level of galectins was associated with clinical characteristics and were potential independent prognostic predictor for GC patients.