Oncostatin M treatment increases the responsiveness toward cisplatin‑based chemoradiotherapy in cervical cancer cells in a STAT3‑dependent manner

Abstract

Abstract. Cervical cancer stage-dependent therapies include surgery, chemotherapy, radiotherapy and chemoradiotherapy. Concurrent cisplatin-based chemoradiotherapy (CCRT) is the standard therapy for locally advanced cervical carcinoma (FIGO>IIB), however therapy resistance in a subset of patients is still a major clinical challenge. The present study aimed to analyze the impact of Oncostatin M (OSM) stimulation on CCRT-induced cell death. The present study used cells derived from cervical squamous cell carcinomas (SW756, 808, CaSki and 879) and adenocarcinoma (HeLa). The cervical carcinoma cells were HPV18-positive (HeLa, SW756, 808) or HPV16-positive (CaSki, 879). In addition to the established cell lines HeLa, SW756 and CaSki, the more recently generated cervical cancer cells 808 and 879 were also used. To analyze their radiosensitivity, cells were treated with increasing doses of irradiation (0-8 Gy). To mimic chemotherapy, radiotherapy or CCRT in vitro, the cells were challenged with 0.975 µg/ml cisplatin, irradiated with 6 Gy or a combination. A total of 10 ng/ml OSM was applied for 2 h prior to the respective therapy. The responsiveness toward radiation alone varied among the cervical carcinoma cells. CaSki, 808 and 879 cells were resistant to irradiation up to 8 Gy. OSM pre-treatment sensitized two out of five cell lines (HeLa and 879) to irradiation. Notably, all tested cells were sensitized by OSM for CCRT-treatment, particularly in the less radiosensitive cells. Cell death enhancement was dependent on phosphorylated signal transducer and activator of transcription 3 (STAT3; Tyr705) signaling activation as demonstrated with a dominant-negative version of STAT3 interfering with phosphorylation at Tyr705 (dnSTAT3-Y705F). In conclusion, OSM pre-treatment was able to override resistance to CCRT via the STAT3 signaling pathway.

Revisiting the role of endogenous STAT3 in HPV‐positive cervical cancer cells

“…Therefore, SiHa and HeLa cells were treated with OSM, which efficiently activates STAT3 signaling in cervical cancer cells. 17,31 Although STAT3 Y705 phosphorylation was substantially induced by OSM treatment after 1 h, as expected, 42 E6/ E7 protein levels (Figure 5E) were not appreciably altered in either SiHa or HeLa cells. Further, whereas transcript levels of the wellestablished STAT3 target gene SOCS3 43 were substantially induced by OSM treatment (Figure 5F, left panel), HPV E6/E7 transcripts did not increase under the same treatment conditions (Figure 5F, right panel).…”

“…Solvent controls were used at a maximum concentration of 0.1% which did not show any effects on cell growth. Oncostatin M (OSM; GenScript Biotech Corporation) was used as indicated for 1, 3, or 6 h at a concentration of 10 ng/mL 17,31 and was dissolved in H 2 O. STAT3 knockout (KO) cells were generated from parental HeLa and SiHa cells by the CRISPR/Cas9 technology, 32 employing two different STAT3-specific guide RNAs (gRNAs). Single cell STAT3 KO clones SiHa G3 and HeLa F3 were generated using the gRNA sense: 5′-CACCGAAAGTGGTAGAGAATCTCC-3′; antisense: 5′-AAACGGAGAT TCTCTACCACTTTC-3′, while for STAT3 KO clones SiHa G7 and HeLa F7 the gRNA sense: 5′-CACCTGTACAGCACCGGCCGATGC-3′; antisense: 5′-AAACGCATCGGCCGGTGCTGTACA-3′ was utilized.…”

Effect of BRCA1 on the Concurrent Chemoradiotherapy Resistance of Cervical Squamous Cell Carcinoma Based on Transcriptome Sequencing Analysis

“…CCND1 is often overexpressed in tumors, and its expression is positively correlated with activation of the JAK/STAT pathway [ 44 ]. In addition, studies showed the JAK/STAT pathway played a crucial role in cisplatin resistance of CC [ 45 , 46 ]. Furthermore, our qPCR validation revealed that STAT1 was upregulated in SiHa cells overexpressing BRCA1 in our study.…”

Proteomic Analysis of Pleural Effusions from COVID-19 Deceased Patients: Enhanced Inflammatory Markers

“…CXCL9/OSM/PD-L1: According to bioinformatics database (Cancer Genome Atlas and Gene Expression Omnibus) analysis which was then confirmed by in vitro and in vivo experiments, PD-L1 expression is upregulated by CXCL9-11 through activation of the STAT/PI3K-Akt pathways [ 39 ]. Interestingly, OSM also binds to the OSM receptor, leading to the recruitment of JAKs and subsequent signal transduction and activation of STAT3 [ 40 ]; thus, we can hypothesize that both CXCL9 and OSM participate in the upregulation of PD-L1 through the STAT activation pathway in COVID-19 patients ( Figure 1 ).…”