Integrated genomic and transcriptomic analysis reveals the activation of PI3K signaling pathway in HPV-independent cervical cancers.

BACKGROUND: HPV-independent cervical cancers (HPV-ind CCs) are uncommon with worse prognosis and poorly understood. This study investigated the molecular characteristics of HPV-ind CCs, aiming to explore new strategies for HPV-ind CCs. METHODS: HPV status of 1010 cervical cancer patients were detected by RT-PCR, PCR and RNA-sequencing (RNA-seq). Whole exome sequencing (WES) and RNA-seq were performed in identified HPV-ind CCs. The efficacy of PI3Kα inhibitor BYL719 in HPV-ind CCs was evaluated in cell lines, patient-derived organoids (PDOs) and patient-derived xenografts (PDXs). RESULTS: Twenty-five CCs were identified as HPV-ind, which were more common seen in older, adenocarcinoma patients and exhibited poorer prognosis as well as higher tumor mutation burden compared to HPV-associated CCs. HPV-ind CCs were featured with highly activated PI3K/AKT signaling pathway, particularly, PIK3CA being the most predominant genomic alteration (36%). BYL719 demonstrated superior tumor suppression in vitro and in vivo. Furthermore, HPV-ind CCs were classified into two subtypes according to distinct prognosis by gene expression profiles, the metabolism subtype and immune subtype. CONCLUSIONS: This study reveals the prevalence, clinicopathology, and molecular features of HPV-ind CCs and emphasizes the importance of PIK3CA mutations and PI3K pathway activation in tumorigenesis, which suggests the potential significance of PI3Kα inhibitors in HPV-ind CC patients.

Genomic profiling of ovarian clear cell carcinoma in Chinese patients reveals potential prognostic biomarkers for survival.

INTRODUCTION: Ovarian clear cell carcinoma (OCCC) has distinct clinical and molecular features and heterogeneous prognosis. Insights into the somatic genomic abnormalities of OCCC provide the basis for deeper understanding and potential therapeutic avenues. Herein, we performed extensive genomic profiling in Chinese patients to illustrate the mutation landscape and genetic prognostic biomarkers of OCCC. PATIENTS AND METHODS: We used targeted DNA sequencing on 61 OCCC cases with a panel of 520 cancer-related genes. Correlations between clinicopathological features and survival were evaluated. Nomogram-based models were constructed to predict progress-free survival (PFS). RESULTS: We detected 763 somatic mutations spanning 286 genes. The most frequent genetic alterations, ARID1A (49%) and PIK3CA (48%), were concurrently mutated. Comprehensive copy number alterations (CNAs) were identified in chromosomes 20q13.2 and 8q. Most (73.7%) patients harboured potentially targetable driver mutations. The mean and median tumour mutational burden were 7.0 and 3.0 mutations/Mb, respectively. Microsatellite instability (high) was identified in 8.2% of patients. Mutation of the base-excision repair pathway was significantly higher in patients of stage II/III/IV. ATM mutation was associated with platinum sensitivity (p < .05). Survival analysis identified chr8q CNAs in all patients, PIK3CA mutations in stage I patients and SWI/SNF complex (ARID1A and SMARCA4) mutations in stage II/III/IV patients as potential prognosticators (p < .05). Integration of genetic alterations (SWI/SNF complex mutations, ATM mutations and chr8q CNAs) improved the performance of a nomogram based on tumour stage and residual disease (concordance index 0.75 vs. 0.70, p < .05). CONCLUSIONS: We described somatic genomic alterations in Chinese OCCC patients and observed different genomic alterations between stage I and stage II/III/IV tumours. Genetic factors may supplement clinical factors in nomogram modelling for PFS prediction.Key MessagesWe performed extensive genomic profiling in a well-annotated cohort of 61 Chinese ovarian clear cell carcinoma (OCCC) patients.PIK3CA mutations were associated with worse overall survival (OS) in stage I OCCC, and SWI/SNF gene mutations were associated with improved OS in stage II/III/IV disease.We propose an easy-to-use nomogram using clinical factors (tumour stage and residual disease) and genetic alterations (SWI/SNF complex mutations, ATM mutations and chr8q CNAs) to predict the progress-free survival (PFS) of OCCC.

The PIK3CA-E545K-SIRT4 signaling axis reduces radiosensitivity by promoting glutamine metabolism in cervical cancer.

The mutation of glutamic acid 545 to lysine (E545K) in PIK3CA, as the most common missense mutation of this gene in various cancer types, is frequently observed in cervical cancer and has been shown to reduce cervical cancer radiosensitivity. However, the underlying mechanisms remain unclear. Here, we implicate the alterations of glutamine metabolism in PIK3CA-E545K-mediated radioresistance of cervical cancer. Specifically, PIK3CA mutation negatively regulated the expression of SIRT4 via the epigenetic regulator EP300 independently of the canonical mTORC1 pathway. PIK3CA-E545K-induced SIRT4 downregulation promoted cell proliferation, migration, and radiation-induced DNA repair and apoptosis, while SIRT4 overexpression reversed the radioresistance phenotype mediated by PIK3CA mutation. Mechanistically, SIRT4 modulated glutamine metabolism and thus cellular apoptosis by negatively regulating a glutamate pyruvate transaminase GPT1. Moreover, the PI3K inhibitor BYL719, but not mTOR inhibitors, exerted remarkable synergistic effects with radiotherapy by inhibiting glutamine metabolism in vitro and in vivo. Collectively, this study reveals the role of PIK3CA-E545K-SIRT4 axis in regulating glutamine metabolism and the radioresistance in cervical cancer, which provides a necessary preliminary basis for clinical research of PI3K inhibitors as radiosensitizing agents.

Investigations on the Changes of Serum Proteins in Rabbits after Trimeresurus stejnegeri Venom Injection via Mass Spectrometry-Based Proteomics.

Purpose: There are few studies on protein phosphorylation in the process of snake poisoning. The purpose of this study was to investigate the toxic mechanism of Trimeresurus stejnegeri at the protein level by determining the differential expression of phosphorylated proteins in rabbits after poisoning using proteomics. Methods: The Trimeresurus stejnegeri venom model in rabbits was established by intramuscular injection of 20 mg/kg venom. The serum was collected and the differential expression of phosphorylated proteins in the serum was determined by the iTRAQ technology, TiO2 enriched phosphorylated peptides, and the mass spectrometry analysis. The functional analysis was conducted using ClueGO software and the related mechanism was evaluated by the network analysis of biological interaction. The expression level of related proteins was determined by the Western blotting assay. Results: Compared to the control group, 77 differentially expressed proteins were observed in the model group. These proteins were closely associated with the complement and agglomerate cascade signaling pathways, the HIF signaling pathway, the pentose phosphate pathway, and the cholesterol metabolism signaling pathway. According to the results of network analysis, TF and SCL16A1 were determined as the core proteins, which were identified by the Western blotting assay. Conclusion: The present study provided valuable phosphorylation signal transduction resources for investigating the toxic mechanism and the therapies for Trimeresurus stejnegeri poisoning.

Fabrication of pH/H2O2-responsive polyhedral oligomeric silsesquioxane self-assembled fluorescent vesicles for enhanced in vivo anti-tumor efficacy.

Aim: The rational design of a fluorescence imaging-guided, highly efficient multiresponsive delivery system is important for improving drug delivery efficiency. Materials and methods: Herein, pH/H2O2-responsive polyhedral oligomeric silsesquioxane (POSS) molecule functionalized 4-(phenyl(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenyl)amino)benzaldehyde (OTB) copolymer (PEG-POSS-OTB) was synthesized to encapsulate doxorubicin (DOX) for precise drug delivery. Results: The self-assembly fluorescent vesicles exhibited excellent pH/H2O2-responsive drug release properties under physiological conditions and efficient drug-targeting ability. In vitro, compared with the DOX group, PEG-POSS-OTB fluorescent vesicles exhibited improved drug delivery and reduced toxicity. Importantly, we performed a proof-of-concept study demonstrating that PEG-POSS-OTB fluorescent vesicles were a high-efficiency nanoassembly drug-delivery platform for improving drug delivery efficiency. In vivo studies demonstrated that PEG-POSS-OTB vesicles with enhanced stability could be used in targeted drug delivery and controlled intelligent release.

Inhibition of STAT6/Anoctamin-1 Activation Suppresses Proliferation and Invasion of Gastric Cancer Cells.

BACKGROUND: Gastric carcinoma is the most popular cancer worldwide. Anoctamin-1 is a calcium-activated channel and highly expressed in various tumors. A previous study indicated that suppressed Anoctamin-1 expression decreased cancer cell proliferation or migration. As a signal transduction and transcription activator, STAT6 is a novel agonist for Anoctamin-1 promoter. However, its role in tumor cell proliferation or migration remains unclear. Therefore, this study aimed to suppress STAT6 and Anoctamin-1 protein expression in gastric cancer cells to test the inhibitory effects on gastric cancer cell migration or invasion. MATERIALS AND METHODS: MTT colorimetry was used to test cell proliferation. Western blot was used to measure STAT6 and Anoctamin-1 expression before and after small interfering RNA (siRNA) treatment. A scratch assay was performed to measure cell migration, followed by Transwell chamber assay analysis of cell invasion. RESULTS: After STAT6 siRNA interference, the expression of STAT6 and Anoctamin-1 was significantly decreased in the gastric carcinoma cell line. Anoctamin-1 siRNA interference only decreased its protein expression, but not STAT6 protein expression. Interference of STAT6 or Anoctamin-1 reduced their protein expression and inhibited proliferation, migration, or invasion of gastric cancer cells. CONCLUSIONS: Inhibition of STAT6/Anoctamin-1 activation decreased proliferation, migration, or invasion of gastric cancer cells, suggesting that the STAT6/Anoctamin-1 pathway might be a novel target for treating gastric cancer.