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.

Reciprocal regulation between RACGAP1 and AR contributes to endocrine therapy resistance in prostate cancer.

BACKGROUND: Endocrine resistance driven by sustained activation of androgen receptor (AR) signaling pathway in advanced prostate cancer (PCa) is fatal. Characterization of mechanisms underlying aberrant AR pathway activation to search for potential therapeutic strategy is particularly important. Rac GTPase-activating protein 1 (RACGAP1) is one of the specific GTPase-activating proteins. As a novel tumor proto-oncogene, overexpression of RACGAP1 was related to the occurrence of various tumors. METHODS: Bioinformatics methods were used to analyze the relationship of expression level between RACGAP1 and AR as well as AR pathway activation. qRT-PCR and western blotting assays were performed to assess the expression of AR/AR-V7 and RACGAP1 in PCa cells. Immunoprecipitation and immunofluorescence experiments were conducted to detect the interaction and co-localization between RACGAP1 and AR/AR-V7. Gain- and loss-of-function analyses were conducted to investigate the biological roles of RACGAP1 in PCa cells, using MTS and colony formation assays. In vivo experiments were conducted to evaluate the effect of RACGAP1 inhibition on the tumor growth. RESULTS: RACGAP1 was a gene activated by AR, which was markedly upregulated in PCa patients with CRPC and enzalutamide resistance. AR transcriptionally activated RACGAP1 expression by binding to its promoter region. Reciprocally, nuclear RACGAP1 bound to the N-terminal domain (NTD) of both AR and AR-V7, blocking their interaction with the E3 ubiquitin ligase MDM2. Consequently, this prevented the degradation of AR/AR-V7 in a ubiquitin-proteasome-dependent pathway. Notably, the positive feedback loop between RACGAP1 and AR/AR-V7 contributed to endocrine therapy resistance of CRPC. Combination of enzalutamide and in vivo cholesterol-conjugated RIG-I siRNA drugs targeting RACGAP1 induced potent inhibition of xenograft tumor growth of PCa. CONCLUSION: In summary, our results reveal that reciprocal regulation between RACGAP1 and AR/AR-V7 contributes to the endocrine resistance in PCa. These findings highlight the therapeutic potential of combined RACGAP1 inhibition and enzalutamide in treatment of advanced PCa.

Knockout of UBE2S inhibits the proliferation of gastric cancer cells and induces apoptosis by FAS-mediated death receptor pathway.

Ubiquitin binding enzyme E2S (UBE2S) is a member of ubiquitin binding enzyme family involved in a variety of biological functions, including cell cycle regulation, apoptosis, and regulation of the ubiquitination of proteins, which are closely correlated with the development of various tumors. However, its role in gastric cancer (GC) remains unknown. In this study, we found that UBE2S was upregulated in GC tissues and cells. Further, its high expression positively correlated with the tumor stage and indicated a poor prognosis. Knockout of UBE2S by CRISPR/Cas9-mediated strategy suppressed the growth of GC in vitro and in vivo. Moreover, RNA-Seq-based transcriptome analysis and tandem mass tag (TMT)-based quantitative proteomics analysis was performed for exploring the underlying mechanism. The multi-omics and verification results showed that UBE2S knockout-induced apoptosis and proliferation inhibition of GC cells was related to upregulation of FAS and the activation of the FAS-mediated apoptotic pathway. Moreover, a negative correlation between UBE2S and FAS expression was observed in GC tissue samples. Finally, the ubiquitination assay confirmed that knockout of UBE2S might activate endogenous FAS by inhibiting ubiquitination and degradation of p53 in GC cells. Collectively, UBE2S is expected to be a novel prognostic biomarker and potential therapeutic target for GC.

Comprehensive analysis of the transcriptional expressions and prognostic value of S100A family in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) remains a treatment-refractory malignancy with poor prognosis. It is urgent to identify novel and valid biomarkers to predict the progress and prognosis of PDAC. The S100A family have been identified as being involved in cell proliferation, migration and differentiation progression of various cancer types. However, the expression patterns and prognostic values of S100As in PDAC remain to be analyzed. METHODS: We investigated the transcriptional expressions, methylation level and prognostic value of S100As in PDAC patients from the Oncomine, GEPIA2, Linkedomics and cBioPortal databases. Real-time PCR was used to detect the expressions of S100A2/4/6/10/14/16 in four pancreatic cancer cell lines and pancreatic cancer tissues from PDAC patients undergoing surgery. To verify the results further, immunohistochemistry was used to measure the expression of S100A2/4/6/10/14/16 in 43 PDAC patients' tissue samples. The drug relations of S100As were analyzed by using the Drugbank database. RESULTS: The results suggested that, the expression levels of S100A2/4/6/10/14/16 were elevated to PDAC tissues than in normal pancreatic tissues, and the promoter methylation levels of S100A S100A2/4/6/10/14/16 in PDAC (n = 10) were lower compared with normal tissue (n = 184) (P < 0.05). In addition, their expressions were negatively correlated with PDAC patient survival. CONCLUSIONS: Taken together, these results suggest that S100A2/4/6/10/14/16 might be served as prognostic biomarkers for survivals of PDAC patients.

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.

The significance of preoperative serum carcinoembryonic antigen levels in the prediction of lymph node metastasis and prognosis in locally advanced gastric cancer: a retrospective analysis.

BACKGROUND: In this study, we aimed to investigate the preoperative serum carcinoembryonic antigen (CEA) in the diagnosis of positive lymph node metastasis (LNM), and to evaluated the relationship between CEA and survival in patients with locally advanced gastric cancer (LAGC). METHODS: The significance of the preoperative serum CEA level for the diagnose of LAGC and prediction of LNM was determined using the receiver operating characteristic (ROC) curve. The areas under the ROC of CEA were compared with those of other tumor markers or imaging examination including CT and MRI. Logistic regression was utilized to identify the risk factors predicting positive LNM. Independent prognosis factors were evaluated using univariate and multivariate COX regression analyses. RESULTS: The ROC curves showed that the AUCs of CEA, CA199, and CA125 for diagnosing LAGC were 0.727, 0.594, and 0.566. When used to predict LNM, the AUC of CEA, CA199 and CA125 were 0.696, 0.531, and 0.588. Logistic regression analysis demonstrated that preoperative serum CEA were significantly associated with positive LNM. On combining imaging examination with CEA, the sensitivity and specificity were 85.3 and 79.4%, respectively, with the AUC equal to 0.853. The combination of CEA and imaging examination preformed the highest levels of AUC and sensitivity for diagnosing LNM, which is significantly higher than using either of them alone. Although patients with abnormal CEA have a poor prognosis, two models of multivariate analysis showed that CEA was not the independent prognosis factor for survival. CONCLUSIONS: CEA can be used to diagnose gastric cancer and determine whether it has LNM. Moreover, combined with CEA could improve the diagnostic sensitivity of imaging examination for lymph node involvement.

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.

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Changes in nuclear morphology are common in malignant tumors, but the underlying molecular mechanisms remain poorly understood. Lamins is involved in supporting nuclear structure, and the expression of Lamins is the molecular basis for nuclear morphological changes during tumor progression. In recent years, the research on the relationship between Lamins and malignant tumors has made great progress. Lamins is of great value in the diagnosis, treatment, and prognosis of various malignant tumors.

Optimization of Ultrasound-Assisted Extraction and Structural Characterization of the Polysaccharide from Pumpkin (Cucurbita moschata) Seeds.

In the present study, ultrasound-assisted extraction (UAE) of crude polysaccharides (PSP) from pumpkin seeds was optimized by response surface method (RSM). The polysaccharide yield (2.29 ± 0.14%), which agreed closely with the theoretical predicted value 2.40%, was obtained under the optimal extraction conditions: extraction time 24 min, extraction temperature 50 °C, ultrasonic power 347 W, and liquid to solid ratio 23 mL/g. After further purification by two-step column chromatography, a novel polysaccharide (PSP-1) was isolated from pumpkin seeds. PSP-1 was composed of mannose, glucose, and galactose in a molar ratio of 1.00:4.26:5.78 with molecular weight of 3728 g/mol. 1D and 2D NMR spectroscopy analysis revealed that the backbone of PSP-1 was mainly formed by ß→6)-ß-d-Galp-(1→, →6)-α-d-Glcp-(1→, and →3,6)-ß-d-Manp-(1→ with branching at O-3 and O-6 of →3,6)-ß-d-Manp-(1→. Branch linkages were composed of α-d-Glcp-(1→ and →4)-α-d-Galp-(1→.

[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.

[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.

[Meta-analysis of total thyroidectomy for multinodular goiter].

OBJECTIVE: To systematically evaluate the efficiency and safety of total thyroidetomy (including near-total tyhroidectomy) versus subtotal thyroidectomy for multinodular goiter. METHODS: The literatures were searched from Cochrane Library, PubMed, Embase, Chinese Biological Medical Datebase, Chinese National Knowledge Infrastructure, and Chinese Science and Technology Journal Full-text Database as of November 2013. We included all randomizad controlled trials on total (including near-total) versus subtotal thyroidectomy in the treatment of multinodular goiter. The collecting of data and quality assessment were respectively completed by 2 researchers. RevMan5.1 software was used for Meta-analysis. RESULTS: We collected 7 literatures conforming to the standard, incuding 2 192 patients. The Metaanalysis outcomes showed that total thyroidectomy was associated with lower nodule recurrence rate (OR=0.13, 95% CI: 0.07-0.22, P<0.001) and higher in transient hypoparathyroidism rate (OR=2.33, 95% CI: 1.72-3.17, P<0.001). However, no statistical difference was seen comparing total and subtotal thyroidectomy in permanent recurrent laryngeal nerve paralysis rate (OR= 0.81, 95% CI: 0.24-2.74, P=0.74) and permanent hypoparathyroidism rate (OR=2.94, 95% CI: 0.48- 18.11, P=0.24). CONCLUSION: Nodule recurrence rate of total thyroidectomy for multinodular goiter is lower than subtotal thyroidectomy and does not increase permanent complications.

Targeted Mevalonate Pathway and Autophagy in Antitumor Immunotherapy.

Tumors of the digestive system are currently one of the leading causes of cancer-related death worldwide. Despite considerable progress in tumor immunotherapy, the prognosis for most patients remains poor. In the tumor microenvironment (TME), tumor cells attain immune escape through immune editing and acquire immune tolerance. The mevalonate pathway and autophagy play important roles in cancer biology, antitumor immunity, and regulation of the TME. In addition, there is metabolic crosstalk between the two pathways. However, their role in promoting immune tolerance in digestive system tumors has not previously been summarized. Therefore, this review focuses on the cancer biology of the mevalonate pathway and autophagy, the regulation of the TME, metabolic crosstalk between the pathways, and the evaluation of their efficacy as targeted inhibitors in clinical tumor immunotherapy.

Mechanisms of Anti-PD Therapy Resistance in Digestive System Neoplasms.

Digestive system neoplasms are highly heterogeneous and exhibit complex resistance mechanisms that render anti-programmed cell death protein (PD) therapies poorly effective. The tumor microenvironment (TME) plays a pivotal role in tumor development, apart from supplying energy for tumor proliferation and impeding the body's anti-tumor immune response, the TME actively facilitates tumor progression and immune escape via diverse pathways, which include the modulation of heritable gene expression alterations and the intricate interplay with the gut microbiota. In this review, we aim to elucidate the mechanisms underlying drug resistance in digestive tumors, focusing on immune-mediated resistance, microbial crosstalk, metabolism, and epigenetics. We will highlight the unique characteristics of each digestive tumor and emphasize the significance of the tumor immune microenvironment (TIME). Furthermore, we will discuss the current therapeutic strategies that hold promise for combination with cancer immune normalization therapies. This review aims to provide a thorough understanding of the resistance mechanisms in digestive tumors and offer insights into potential therapeutic interventions.

Hyperbaric oxygen preconditioning rescues prolonged underwater exercise-induced hippocampal dysfunction by regulating microglia activation and polarization.

Underwater exercise is becoming increasingly prevalent, during which brain function is necessary but is also at risk. However, no study has explored how prolonged exercise affect the brain in underwater environment. Previous studies have indicated that excessive exercise in common environment causes brain dysfunction but have failed to provide appropriate interventions. Numerous evidence has indicated the neuroprotective effect of hyperbaric oxygen preconditioning (HBO-PC). The objective of this study was to investigate the cognitive effect of prolonged underwater exercise (PUE) and to explore the potential neuroprotective effect of HBO-PC in underwater environment. Rats swimming for 3 h in a simulated hyperbaric chamber (2.0 ATA) was used to establish the PUE animal model and HBO-PC (2.5 ATA for 1, 3,5 times respectively) was administrated before PUE. The results demonstrated that PUE triggers anxiety-like behaviors, cognitive impairment accompanied by hippocampal dysfunction, microglia activation and neuroinflammation. Conversely, 3 HBO-PC rescued anxiety-like behaviors and cognitive impairment. Mechanistically, 3 HBO-PC reduced microglia activation and switched the activated microglia from a pro-inflammatory to neuroprotective phenotype. These findings illustrated that PUE induces anxiety-like behaviors and cognitive impairment and HBO-PC of proper frequency may provide an appropriate and less invasive intervention for protecting the brain in underwater exercise.

Identification of recurrent BRAF non-V600 mutations in intraductal carcinoma of the prostate in Chinese populations.

While BRAF alterations have been established as a driver in various solid malignancies, the characterization of BRAF alterations in prostate cancer (PCa) has not been thoroughly interrogated. By bioinformatics analysis, we first found that BRAF alterations were associated with advanced PCa and exhibited mutually exclusive pattern with ERG alteration across multiple cohorts. Of the most interest, recurrent non-V600 BRAF mutations were found in 3 of 21 (14.3 %) PCa patients demonstrating IDC-P morphology. Furthermore, experimental overexpression of BRAFK601E and BRAFL597R exhibited emergence of oncogenic phenotypes with intensified MAPK signaling in vitro, which could be targeted by MEK inhibitors. Comparison of the incidence of BRAF alterations in IDC-P between western and Chinese ancestry revealed an increased prevalence in the Chinese population. The BRAF mutation may represent important genetic alteration in a subset of IDC-P, highlighting the role of MAPK signaling pathway in this subtype of PCa. To the best of knowledge, this is the first description of non-V600 BRAF mutation in setting of IDC-P, which may in part explain the aggressive phenotype seen in IDC-P and could also bring more treatment options for PCa patients with IDC-P harboring such mutations.

Relationship between psychological adaptability and work engagement of college teachers within smart teaching environments: the mediating role of digital information literacy self-efficacy.

Introduction: Integrating the Internet and traditional teaching has enriched teaching resources and methods and introduced many advanced digital media. The smart teaching process is influenced by teachers' psychological adaptability, which can be affected by teachers' work engagement. However, the relationship between the two has not received sufficient attention in the literature. This study aims to analyze the relationship between college teachers' psychological adaptability and work engagement in a smart teaching environment. Methods: Applying structural equation modeling (SEM) to a sample of 373 front-line teachers, this study focuses on the mediating effect of digital information literacy self-efficacy on the relationship between teachers' psychological adaptability and work engagement. Results: The results show that the four dimensions of college teachers' psychological adaptability strongly influence work engagement and digital information literacy self-efficacy. In particular, teachers' psychological adaptability and work engagement are positively correlated; teachers' self-efficacy can positively affect the three dimensions of their work engagement, and teachers' psychological adaptability can positively affect their digital information literacy self-efficacy. Conclusion: The above results can serve as a basis for the development and improvement of the training of college teachers and the implementation of smart teaching. The study findings highlight the importance of training teachers on information technology teaching and implementing measures to enhance teachers' digital information literacy self-efficacy. Training should focus on the knowledge and skills of teachers using information technology teaching and increase the practical links of teachers using information technology teaching.

Combined Inhibition of KIF11 and KIF15 as an Effective Therapeutic Strategy for Gastric Cancer.

BACKGROUND: Novel therapeutic strategies are urgently required to improve clinical outcomes of gastric cancer (GC). KIF15 cooperates with KIF11 to promote bipolar spindle assembly and formation, which is essential for proper sister chromatid segregation. Therefore, we speculated that the combined inhibition of KIF11 and KIF15 might be an effective strategy for GC treatment. Hence, to test this hypothesis, we aimed to evaluate the combined therapeutic effect of KIF15 inhibitor KIF15- IN-1 and KIF11 inhibitor ispinesib in GC. METHODS: We validated the expression of KIF11 and KIF15 in GC tissues using immunohistochemistry and immunoblotting. Next, we determined the effects of KIF11 or KIF15 knockout on the proliferation of GC cell lines. Finally, we investigated the combined effects of the KIF11 and KIF15 inhibitors both in vitro and in vivo. RESULTS: KIF11 and KIF15 were overexpressed in GC tissues than in the adjacent normal tissues. Knockout of either KIF11 or KIF15 inhibited the proliferative and clonogenic abilities of GC cells. We found that the KIF15 knockout significantly increased ispinesib sensitivity in GC cells, while its overexpression showed the opposite effect. Further, using KIF15-IN-1 and ispinesib together had a synergistic effect on the antitumor proliferation of GC both in vitro and in vivo. CONCLUSION: This study shows that the combination therapy of inhibiting KIF11 and KIF15 might be an effective therapeutic strategy against gastric cancer.

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.

RUVBL1 promotes enzalutamide resistance of prostate tumors through the PLXNA1-CRAF-MAPK pathway.

Although enzalutamide improves the overall survival of patients with metastatic prostate cancers, enzalutamide resistance (ENZR) will be inevitably developed. Emerging evidence support that alternative oncogenic pathways may bypass the androgen receptor (AR) signaling to promote ENZR progression, however, the underpinning mechanisms remain poorly defined. Here, we report that the expression of RuvB like AAA ATPase 1 (RUVBL1) is upregulated in ENZR cells and xenograft models and prostate tumors in patients. Enzalutamide increases RUVBL1 accumulation in the cytoplasm, which in turn enhances the recruitment of CRAF proto-oncogene serine/threonine kinase protein to plexin A1 (PLXNA1) and the subsequent activation of the downstream MAPK pathway. Co-overexpression of RUVBL1 and PLXNA1 defines a subgroup of prostate cancer (PCa) patients with a poor prognosis. Furthermore, pharmacological inhibition of RUVBL1 by CB-6644 suppresses ENZR cell proliferation and xenograft growth and allows re-sensitization of ENZR cells and xenografts to enzalutamide, indicating that RUVBL1 may act to substitute the AR signaling to promote cancer cell survival and ENZR development. Together, these findings may lead to the identification of RUVBL1 as a potential therapeutic target for ENZR tumors.