Cyclin A2 confers cisplatin resistance to endometrial carcinoma cells via up-regulation of an Akt-binding protein, periplakin

Advances in research on autophagy mechanisms in resistance to endometrial cancer treatment

Administering medication is a crucial strategy in improving the prognosis for advanced endometrial cancer. However, the rise of drug resistance often leads to the resurgence of cancer or less-than-ideal treatment outcomes. Prior studies have shown that autophagy plays a dual role in the development and progression of endometrial cancer, closely associated with drug resistance. As a result, concentrating on autophagy and its combination with medical treatments might be a novel approach to improve the prognosis for endometrial cancer. This study explores the impact of autophagy on drug resistance in endometrial cancer, investigates its core mechanisms, and scrutinizes relevant treatments aimed at autophagy, aiming to illuminate the issue of treatment resistance in advanced endometrial cancer.

PIM1 is a Poor Prognostic Factor for and Potential Therapeutic Target in Serous Carcinoma of the Endometrium

Serous carcinoma (SC) is an aggressive histologic type of endometrial carcinoma (EMC) with a poor prognosis. The development of novel therapeutics for SC is an important issue. PIM1 is a serine/threonine kinase involved in various cellular functions, such as cell cycle progression, apoptosis, and transcriptional activation via the phosphorylation of many target proteins, including MYC. PIM1 is overexpressed in several cancers and has been associated with treatment-resistance. We investigated the expression and function of PIM1 in EMC, particularly SC. Immunohistochemical analysis in 133 EMC cases [103 endometrioid carcinomas (EC) and 30 SC] revealed the significantly stronger expression of PIM1 in SC than in EC and significantly shorter survival of patients with overexpression of PIM1 in all EMC cases, as well as in only SC cases. A multivariate analysis identified overexpression of PIM1 as an independent prognostic factor. The knockdown of PIM1 by siRNA in the SC cell line, ARK1, decreased the expression of phosphorylated MYC and reduced proliferation, migration, and invasion. The PIM1 inhibitor, SGI-1776, reduced cell viability in SC cell lines (ARK1, ARK2, and SPAC1L) with IC50 between 1 and 5 µM. SGI-1776 also reduced the migration and invasion of ARK1 cells. Moreover, the oral administration of SGI-1776 significantly suppressed subcutaneous ARK1 xenograft tumor growth in nude mice without impairing health. These results indicate that PIM1 is involved in the acquisition of aggressiveness and suggest the potential of PIM1 as a novel therapeutic target and SGI-1776 as a therapeutic agent for SC.

Multiomic analysis identifies CPT1A as a potential therapeutic target in platinum-refractory, high-grade serous ovarian cancer

Resistance to platinum compounds is a major determinant of patient survival in high-grade serous ovarian cancer (HGSOC). To understand mechanisms of platinum resistance and identify potential therapeutic targets in resistant HGSOC, we generated a data resource composed of dynamic (±carboplatin) protein, post-translational modification, and RNA sequencing (RNA-seq) profiles from intra-patient cell line pairs derived from 3 HGSOC patients before and after acquiring platinum resistance. These profiles reveal extensive responses to carboplatin that differ between sensitive and resistant cells. Higher fatty acid oxidation (FAO) pathway expression is associated with platinum resistance, and both pharmacologic inhibition and CRISPR knockout of carnitine palmitoyltransferase 1A (CPT1A), which represents a rate limiting step of FAO, sensitize HGSOC cells to platinum. The results are further validated in patient-derived xenograft models, indicating that CPT1A is a candidate therapeutic target to overcome platinum resistance. All multiomic data can be queried via an intuitive gene-query user interface (https://sites.google.com/view/ptrc-cell-line).

Association of a novel endometrial cancer biomarker panel with prognostic risk, platinum insensitivity, and targetable therapeutic options

During the past decade, the age-adjusted mortality rate for endometrial cancer (EC) increased 1.9% annually with TP53 mutant (TP53-mu) EC disproportionally represented in advanced disease and deaths. Therefore, we aimed to assess pivotal molecular parameters that differentiate clinical outcomes in high- and low-risk EC. Using the Cancer Genome Atlas, we analyzed EC specimens with available DNA sequences and quantitative gene-specific RNA expression data. After polymerase ɛ (POLE)-mutant specimens were excluded, differential gene-specific mutations and mRNA expressions were annotated and integrated. Consequent to TP53-mu failure to induce p21, derepression of multiple oncogenes harboring promoter p21 repressive sites was observed, including CCNA2 and FOXM1 (P < .001 compared with TP53 wild type [TP53-wt]). TP53-wt EC with high CCNA2 expression (CCNA2-H) had a targeted transcriptomic profile similar to that of TP53-mu EC, suggesting CCNA2 is a seminal determinant for both TP53-wt and TP53-mu EC. CCNA2 enhances E2F1 function, upregulating FOXM1 and CIP2A, as observed in TP53-mu and CCNA2-H TP53-wt EC (P < .001). CIP2A inhibits protein phosphatase 2A, leading to AKT inactivation of GSK3β and restricted oncoprotein degradation; PPP2R1A and FBXW7 mutations yield similar results. Upregulation of FOXM1 and failed degradation of FOXM1 is evidenced by marked upregulation of multiple homologous recombination genes (P < .001). Integrating these molecular aberrations generated a molecular biomarker panel with significant prognostic discrimination (P = 5.8×10⁻⁷); adjusting for age, histology, grade, myometrial invasion, TP53 status, and stage, only CCNA2-H/E2F1-H (P = .0003), FBXW7-mu/PPP2R1A-mu (P = .0002), and stage (P = .017) were significant. The generated prognostic molecular classification system identifies dissimilar signaling aberrations potentially amenable to targetable therapeutic options.

Cancer risk susceptibility loci in a Swedish population

A germline mutation in cancer predisposing genes is known to increase the risk of more than one tumor type. In order to find loci associated with many types of cancer, a genome-wide association study (GWAS) was conducted, and 3,555 Swedish cancer cases and 15,581 controls were analyzed for 226,883 SNPs. The study used haplotype analysis instead of single SNP analysis in order to find putative founder effects. Haplotype association studies identified seven risk loci associated with cancer risk, on chromosomes 1, 7, 11, 14, 16, 17 and 21. Four of the haplotypes, on chromosomes 7, 14, 16 and 17, were confirmed in Swedish familial cancer cases. It was possible to perform exome sequencing in one patient for each of those four loci. No clear disease-causing exonic mutation was found in any of the four loci. Some of the candidate loci hold several cancer genes, suggesting that the risk associated with one locus could involve more than one gene associated with cancer risk. In summary, this study identified seven novel candidate loci associated with cancer risk. It was also suggested that cancer risk at one locus could depend on multiple contributing risk mutations/genes.

iTRAQ-coupled 2D LC/MS-MS analysis of CXCR7-transfected papillary thyroid carcinoma cells: A new insight into CXCR7 regulation of papillary thyroid carcinoma progression and identification of potential biomarkers

Previous studies have demonstrated that C-X-C chemokine receptor type 7 (CXCR7) regulates papillary thyroid carcinoma (PTC) growth and metastasis; however, the molecular mechanisms underlying this regulation remain unclear. In the present study, the protein expression profiles of the PTC cell line GLAG-66 and GLAG-66 cells stably transfected with CXCR7 cDNA were analyzed and compared using isobaric tag for relative and absolute quantification-coupled two-dimensional liquid chromatography-tandem mass spectrometry. In total, 2,983 proteins were quantified and 130 proteins were identified to be differentially expressed, of which 87 were significantly upregulated and 43 were significantly downregulated. Gene Ontology enrichment analysis revealed that the differentially expressed proteins were primarily enriched in a number of biological processes, including metabolism-related processes, cellular component organization, transport, cellular development process and the immune response. The differentially expressed proteins identified included fibronectin 1, basigin, periplakin and serpin family B member 5, all of which are associated with cellular junctions and cancer progression. In addition, transgelin-2 and AHNAK nucleoprotein 2 were identified as potential novel biomarkers for the prognosis and treatment of PTC.

SIRT1 Regulates the Chemoresistance and Invasiveness of Ovarian Carcinoma Cells

BACKGROUND

SIRT1 is a longevity gene that forestalls aging and age-related diseases including cancer, and has recently attracted widespread attention due to its overexpression in some cancers. We previously identified the overexpression of SIRT1 in ovarian carcinoma (OvCa) as a poor prognostic factor. However, mechanistic insights into the function of SIRT1 in OvCa have yet to be elucidated.

METHODS

Quantitative real-time reverse PCR (qRT-PCR) and Western blotting were employed to examine the expression of SIRT1 in a panel of human OvCa cell lines. si-RNA or sh-RNA and cDNA technologies were utilized to knockdown or overexpress SIRT1, respectively. The effects of SIRT1 on proliferation and chemoresistance were examined using a WST-1 assay, and the underlying mechanisms were confirmed using an apoptotic assay, and the quantification of glutathione (GSH), and reactive oxygen species (ROS). The aggressiveness of SIRT1 was analyzed using in vitro invasion and migration assays.

RESULTS

SIRT1 was more strongly expressed in OvCa cell lines than in the immortalized ovarian epithelium at the gene and protein levels. Stress up-regulated the expression of SIRT1 in dose- and time-dependent manners. SIRT1 significantly enhanced the proliferation (P<.05), chemoresistance (P<.05), and aggressiveness of OvCa cells by up-regulating multiple antioxidant pathways to inhibit oxidative stress. Further study into the overexpression of SIRT1 demonstrated the up-regulation of several stemness-associated genes and enrichment of CD44v9 via an as-yet-unidentified pathway.

CONCLUSIONS

Our results suggest that SIRT1 plays a role in the acquisition of aggressiveness and chemoresistance by OvCa, and has potential as a therapeutic target for OvCa.

RNA sequencing of pancreatic adenocarcinoma tumors yields novel expression patterns associated with long-term survival and reveals a role for ANGPTL4

BACKGROUND

Pancreatic adenocarcinoma patients have low survival rates due to late-stage diagnosis and high rates of cancer recurrence even after surgical resection. It is important to understand the molecular characteristics associated with survival differences in pancreatic adenocarcinoma tumors that may inform patient care.

RESULTS

RNA sequencing was performed for 51 patient tumor tissues extracted from patients undergoing surgical resection, and expression was associated with overall survival time from diagnosis. Our analysis uncovered 323 transcripts whose expression correlates with survival time in our pancreatic patient cohort. This genomic signature was validated in an independent RNA-seq dataset of 68 additional patients from the International Cancer Genome Consortium. We demonstrate that this transcriptional profile is largely independent of markers of cellular division and present a 19-transcript predictive model built from a subset of the 323 transcripts that can distinguish patients with differing survival times across both the training and validation patient cohorts. We present evidence that a subset of the survival-associated transcripts is associated with resistance to gemcitabine treatment in vitro, and reveal that reduced expression of one of the survival-associated transcripts, Angiopoietin-like 4, impairs growth of a gemcitabine-resistant pancreatic cancer cell line.

CONCLUSIONS

Gene expression patterns in pancreatic adenocarcinoma tumors can distinguish patients with differing survival outcomes after undergoing surgical resection, and the survival difference could be associated with the intrinsic gemcitabine sensitivity of primary patient tumors. Thus, these transcriptional differences may impact patient care by distinguishing patients who would benefit from a non-gemcitabine based therapy.

Low Doses of Cisplatin Induce Gene Alterations, Cell Cycle Arrest, and Apoptosis in Human Promyelocytic Leukemia Cells

Cisplatin is a known antitumor drug, but its mechanisms of action are not fully elucidated. In this research, we studied the anticancer potential of cisplatin at doses of 1, 2, or 3 µM using HL-60 cells as a test model. We investigated cisplatin effects at the molecular level using RNA sequencing, cell cycle analysis, and apoptotic assay after 24, 48, 72, and 96 hours of treatment. The results show that many genes responsible for molecular and cellular functions were significantly altered. Cisplatin treatment also caused the cells to be arrested at the DNA synthesis phase, and as the time increases, the cells gradually accumulated at the sub-G1 phase. Also, as the dose increases, a significant number of cells entered into the apoptotic and necrotic stages. Altogether, the data show that low doses of cisplatin significantly impact the viability of HL-60 cells, through modulation of gene expression, cell cycle, and apoptosis.

Integrated microRNA and mRNA transcriptome sequencing reveals the potential roles of miRNAs in stage I endometrioid endometrial carcinoma

Endometrioid endometrial carcinoma (EEC) is the most dominant subtype of endometrial cancer. Aberrant transcriptional regulation has been implicated in EEC. Herein, we characterized mRNA and miRNA transcriptomes by RNA sequencing in EEC to investigate potential molecular mechanisms underlying the pathogenesis. Total mRNA and small RNA were simultaneously sequenced by next generation sequencing technology for 3 pairs of stage I EEC and adjacent non-tumorous tissues. On average, 52,716,765 pair-end 100 bp mRNA reads and 1,669,602 single-end 50 bp miRNA reads were generated. Further analysis indicated that 7 miRNAs and 320 corresponding target genes were differentially expressed in the three stage I EEC patients. Six of all the seven differentially expressed miRNAs were targeting on eleven differentially expressed genes in the cell cycle pathway. Real-time quantitative PCR in sequencing samples and other independent 21 pairs of samples validated the miRNA-mRNA differential co-expression, which were involved in cell cycle pathway, in the stage I EEC. Thus, we confirmed the involvement of hsa-let-7c-5p and hsa-miR-99a-3p in EEC and firstly found dysregulation of hsa-miR-196a-5p, hsa-miR-328-3p, hsa-miR-337-3p, and hsa-miR-181c-3p in EEC. Moreover, synergistic regulations among these miRNAs were detected. Transcript sequence variants such as single nucleotide variant (SNV) and short insertions and deletions (Indels) were also characterized. Our results provide insights on dysregulated miRNA-mRNA co-expression and valuable resources on transcript variation in stage I EEC, which implies the new molecular mechanisms that underlying pathogenesis of stage I EEC and supplies opportunity for further in depth investigations.

Prognostic significance of Notch signalling molecules and their involvement in the invasiveness of endometrial carcinoma cells

AIMS

The aim of this study was to investigate the significance of the expression of Notch-related molecules in endometrial carcinoma.

METHODS AND RESULTS

The expression of Notch receptors (Notch1 and 3) and Notch ligands [Jagged (JAG) 1 and Delta-like (DLL) 4] was examined immunohistochemically in 37 normal and 76 malignant endometrial tissue samples. For each section, immunohistochemical staining was scored using a positivity index (PI, full score; 200). The effects of a Notch inhibitor, DAPT, on cell proliferation, invasion and motility were investigated using endometrial carcinoma cell lines. The PIs for Notch1 (mean±SD 90.4±15.3), Notch3 (95.6 ± 20.4), JAG1 (95.5±10.0) and DLL4 (88.2±9.6), were significantly higher in endometrial carcinoma than normal endometrium. The PI for Notch1 was associated significantly with advanced International Federation of Gynecologists & Obstetricians (FIGO) stage. In addition, patients with tumours showing high expression of both Notch1 and JAG1 had a poor prognosis compared with those having double-negative carcinomas (P=0.015). DAPT suppressed invasiveness of cells derived from the endometrial carcinoma cell line KLE.

CONCLUSIONS

The Notch1-JAG1 axis may enhance the invasive properties of endometrial carcinomas, which suggests the Notch pathway may be a promising target for the treatment of this malignancy.