A risk model of gene signatures for predicting platinum response and survival in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is the deadliest tumor in the female reproductive tract. And increased resistance to platinum-based chemotherapy represents the major obstacle in the treatment of OC currently. Robust and accurate gene expression models are crucial tools in distinguishing platinum therapy response and evaluating the prognosis of OC patients.

METHODS

In this study, 230 samples from The Cancer Genome Atlas (TCGA) OV dataset were subjected to mRNA expression profiling, single nucleotide polymorphism (SNP), and copy number variation (CNV) analysis comprehensively to screen out the differentially expressed genes (DEGs). An SVM classifier and a prognostic model were constructed using the Random Forest algorithm and LASSO Cox regression model respectively via R. The Gene Expression Omnibus (GEO) database was applied as the validation set.

RESULTS

Forty-eight differentially expressed genes (DEGs) were figured out through integrated analysis of gene expression, single nucleotide polymorphism (SNP), and copy number variation (CNV) data. A 10-gene classifier was constructed which could discriminate platinum-sensitive samples precisely with an AUC of 0.971 in the training set and of 0.926 in the GEO dataset (GSE638855). In addition, 8 optimal genes were further selected to construct the prognostic risk model whose predictions were consistent with the actual survival outcomes in the training cohort (p = 9.613e-05) and validated in GSE638855 (p = 0.04862). PNLDC1, SLC5A1, and SYNM were then identified as hub genes that were associated with both platinum response status and prognosis, which was further validated by the Fudan University Shanghai cancer center (FUSCC) cohort.

CONCLUSION

These findings reveal a specific risk model that could serve as effective biomarkers to identify patients' platinum response status and predict survival outcomes for OC patients. PNLDC1, SLC5A1, and SYNM are the hub genes that may serve as potential biomarkers in OC treatment.

Efficacy and safety of low-dose apatinib in ovarian cancer patients with platinum-resistance or platinum-refractoriness: A single-center retrospective study

BACKGROUND

This study aimed to evaluate the efficacy and safety of apatinib with a low dose of 250 mg/d in the treatment of platinum-resistant or platinum-refractory ovarian cancer patients.

METHODS

Patients with platinum-resistant or platinum-refractory ovarian carcinoma treated with 250 mg/d apatinib in our institution from November 2016 to December 2017 were retrospectively reviewed. The tumor response and progression were evaluated according to the standard by incorporating the levels of CA125 and Response Evaluation Criteria in Solid Tumors 1.1. CTCAE 4.03 was used to evaluate adverse events (AEs).

RESULTS

Fifty-two eligible patients were enrolled in per-protocol (PP) analysis and 65 patients (including 13 lost to follow-up) were included in the intention-to-treat (ITT) analysis. In PP analysis, 18 patients (34.6%) had partial response (PR), 22 patients (42.3%) had stable disease (SD), and the disease control rate (DCR) was 61.5%. Median progression-free survival (PFS) was 4.0 months (95% CI, 2.83-5.17 m), and median overall survival (OS) was 25.33 months (95% CI, 17.74-32.92 m). The objective response rate and DCR for patients in ITT analysis were 27.7% and 49.2%, respectively. The top three treatment-related AEs were hypertension, hand-foot syndrome, and leukopenia. Eight patients (15.4%) in PP population had grade 3 treatment-related AEs. Previous chemotherapy lines, number of recurrences, and AEs did not affect the efficacy of apatinib. Age older than 60 was associated with higher rates of disease control and prolonged PFS (P < .05).

CONCLUSION

Apatinib 250 mg/d is a feasible treatment in platinum-resistant or platinum-refractory epithelial ovarian cancer (EOC) patients.

Identification of Somatic Genetic Alterations Using Whole-Exome Sequencing of Uterine Leiomyosarcoma Tumors

BACKGROUND

The genomic abnormalities associated with uterine leiomyosarcoma (uLMS) have not been fully elucidated to date.

OBJECTIVE

To understand the pathogenesis of uLMS and to identify driver mutations and potential therapeutic targets in uLMS.

METHODS

Three matched tumor-constitutional DNA pairs from patients with recurrent uLMS were subjected to whole-exome capture and next-generation sequencing. The role of the selected gene SHARPIN in uLMS was analyzed by the CCK-8 assay and colony formation assay after specific siRNA knockdown.

RESULTS

We identified four genes with somatic SNVs, namely, SLC39A7, GPR19, ZNF717, and TP53, that could be driver mutations. We observed that 30.7% (4/13) of patients with uLMS had TP53 mutations as analyzed by direct sequencing. Analysis of somatic copy number variants (CNVs) showed regions of chromosomal gain at 1q21-23, 19p13, 17q21, and 17q25, whereas regions of chromosomal loss were observed at 2q35, 2q37, 1p36, 10q26, 6p22, 8q24, 11p15, 11q12, and 9p21. The SHARPIN gene was amplified in two patients and mutated in another (SHARPIN: NM_030974: exon2: c.G264C, p.E88D). Amplification of the SHARPIN gene was associated with shorter PFS and OS in soft tissue sarcoma, as shown by TCGA database analysis. Knockdown of SHARPIN expression was observed to decrease cell growth and colony formation in uterine sarcoma cell lines.

CONCLUSIONS

Exome sequencing revealed mutational heterogeneity of uLMS. The SHARPIN gene was amplified in uLMS and could be a candidate oncogene.