Cytotoxic reaction mediators: granzymes A and B in women with ovarian cancer

NK cell line modified to express a potent, DR5 specific variant of TRAIL, show enhanced cytotoxicity in ovarian cancer models

Objective

Ovarian cancer is a lethal gynaecological malignancy with unsatisfactory 5 year survival rates of 30-50 %. Cell immunotherapy is a promising new cancer treatment where immune cells, such as Natural Killer (NK) cells, are administered to enable the patient to fight cancer through direct cytotoxicity. NK cells orchestrate an adaptive immune response by enabling the release of tumour antigens. NK cell cytotoxicity and effector responses are largely driven by TRAIL engagement. In this study we investigated the cytotoxic potential of a human NK cell line that were modified to express a potent DR5 specific TRAIL variant. We hypothesised that this modification would enhance NK cell cytotoxicity against TRAIL sensitive and resistant ovarian cancer cell lines in vitro.

Methods

KHYG-1 human NK cells were modified with a TRAIL variant targeting DR5 (TRAILv-KHYG-1). Human ovarian cancer cell lines, OVCAR-3 and SKOV-3, were cultured with modified or non-modified NK cells at different effector:target (E:T) ratios for 4 or 16 h. Apoptosis was assessed by Annexin-APC and 7-AAD and measured using flow cytometry. Apoptotic cells were defined as annexin V 7-AAD double positive. Cytokine expression was measured by multiplex ELISA, and analysed by flow cytometry.

Results

Modified and non-modified NK cells significantly reduced OVCAR-3 cell viability as compared to OVCAR-3 cells that were cultured alone after 4 and 16 h treatment. OVCAR-3 cell viability was reduced after treatment with 1:1 E:T ratio with TRAILv-KHYG-1 cells after 16 h. On the contrary, neither NK cell line had any effect of SKOV-3 cell viability despite SKOV-3 cells having more DR5 surface expression compared to OVCAR-3 cells.

Conclusions

TRAILv-KHYG-1 cells significantly reduced OVCAR-3 cell viability as compared to non-modified NK cells. However, no significant reduction in viability was observed when SKOV-3 cell were cultured with either NK cells, despite having more DR5 surface expression compared to OVCAR-3 cells. These data indicate that mechanisms other than DR5 expression drive TRAIL resistance in ovarian cancer.

A Novel Pyroptosis-Related Gene Signature for Predicting the Prognosis and the Associated Immune Infiltration in Colon Adenocarcinoma

Background

Pyroptosis has been demonstrated to be an inflammatory form of programmed cell death recently. However, the expression of pyroptosis-related genes (PRGs) in colon adenocarcinoma (COAD) and their correlations with prognosis remain unclear.

Methods

Data of COAD patients were obtained from The Cancer Genome Atlas (TCGA) database to screen differentially expressed genes (DEGs). Univariate Cox regression analysis and the LASSO Cox regression analysis were applied to construct a gene signature. All COAD patients in TCGA cohort were separated into low-risk subgroup or high-risk subgroup via the risk score. Kaplan–Meier survival analysis and receiver operator characteristic (ROC) curves were adopted to assess its prognostic efficiency. COAD data from the GSE17537 datasets was used for validation. A prognostic nomogram was established to predict individual survival. The correlation between PRGs and immune cell infiltration in COAD was verified based on TIMER database. CIBERSORT analysis was utilized on risk subgroup as defined by model. The protein and mRNA expression level of PRGs were verified by HPA database and qPCR.

Results

A total of 51 differentially expressed PRGs were identified in TCGA cohort. Through univariate Cox regression analysis and LASSO Cox regression analysis, a prognostic model containing 7 PRGs was constructed. Kaplan–Meier survival analysis indicated that patients in the low-risk subgroup exhibited better prognosis compared to those in the high-risk subgroup. Additionally, the area under the curve (AUC) of ROC is 0.60, 0.63, and 0.73 for 1-, 3-, and 5-year survival in TCGA cohort and 0.63, 0.65, and 0.64 in validation set. TIMER database showed a strong correlation between 7 PRGs and tumor microenvironment in COAD. Moreover, CIBERSORT showed significant differences in the infiltration of plasma cells, M0 macrophages, resting dendritic cells, and eosinophils between low-risk subgroup and high-risk subgroup. HPA database showed that protein expression level of SDHB, GZMA, BTK, EEF2K, and NR1H2 was higher in normal tissues. And the transcriptional level of CASP5, BTK, SDHB, GZMA, and RIPK3 was high in normal tissues.

Conclusions

Our study identified a novel PRGs signature that could be used to predict the prognosis of COAD patients, which might provide a new therapeutic target for the treatment of COAD patients.

Active FOXO1 Is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming

Progesterone promotes differentiation coupled to proliferation and prosurvival in the breast, but inhibits estrogen-driven growth in the reproductive tract and ovaries. Herein, it is demonstrated, using progesterone receptor (PR) isoform-specific ovarian cancer model systems, that PR-A and PR-B promote distinct gene expression profiles that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target gene p21 (CDKN1A) are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15 (CDKN2B). Chromatin immunoprecipitation (ChIP) assays performed on PR isoform-specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin marks. Overexpression of constitutively active FOXO1 in PR-A-expressing cells conferred robust ligand-dependent upregulation of the PR-B target genes GZMA, IGFBP1, and p21, and induced cellular senescence. In the presence of endogenous active FOXO1, PR-A was phosphorylated on Ser294 and transactivated PR-B at PR-B target genes; these events were blocked by the FOXO1 inhibitor (AS1842856). PR isoform-specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin; loss of progestin sensitivity correlated with high AKT activity.

IMPLICATIONS

This study indicates FOXO1 as a critical component for progesterone signaling to promote cellular senescence and reveals a novel mechanism for transcription factor control of hormone sensitivity.