HSPA1A, HSPA1L and TRAP1 heat shock genes may be associated with prognosis in ovarian epithelial cancer
ONCOLOGY LETTERS
Authors: De Andrade, Warne Pedro; Braga, Leticia Da Conceicao; Goncales, Nikole Gontijo; Silva, Luciana Maria; Da Silva Filho, Agnaldo Lopes
Abstract
Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with the presence of chemoresistance contributing to the poor prognosis. Heat Shock Proteins (HSPs) genes are activated in response to pathophysiological stress and serve a role in a variety of stages in carcinogenesis, acting primarily as anti-apoptotic agents and in chemotherapy resistance in a variety of tumor types. The current study evaluated the HSP gene expression profile in women with ovarian cancer (OC) and their correlation with clinical and pathological aspects of patients with OC. A total of 51 patients included in the current study were divided into four groups: Primary Epithelial Ovarian Cancer (EOC; n=14), metastatic EOC (n=11), ovarian serous cystadenoma (n=7) and no evidence of ovarian malignancy or control groups (n=19). RNA extraction and reverse transcription-quantitative (RT-q) PCR was then performed on the samples obtained. RT-qPCR was performed to compare TNF receptor associated protein 1 (TRAP]), heat shock protein family (HSP) HSPB1, HSPD1, HSPA1A and HSPA1L expression in primary and metastatic EOCs. TRAP], HSPB1, HSPD1, HSPA1A and HSPAlL gene expression did not differ among groups. HSPA1A, HSPA]L and TRAP] were revealed to be underexpressed in the primary and metastatic EOC groups, with HSPA1L exhibiting the lowest expression. TRAP] expression was higher in tumors at stages I/II compared with those at stages III/IV. No correlation was exhibited between HSP expression and age, menarche, menopause, parity, period after menopause initiation, cytoreduction, CA-125 or overall and disease-free survival. HSPA1A was negatively correlated with the risk of mortality from OC. The results indicated that the downregulation of HSPA1A, HSPA1L and TRAP] could be associated with the clinical prognostic features of women with EOC.
Differential hypoxic tolerance is mediated by activation of heat shock response and nitric oxide pathway
CELL STRESS & CHAPERONES
Authors: Jain, Kanika; Suryakumar, Geetha; Ganju, Lilly; Singh, Shashi Bala
Abstract
The fall in ambient oxygen pressure in high-altitude milieu elicits a wide range of physiological responses in the myocardium, which may differ from individual to individual. This condition, known as hypobaric hypoxia, invokes the cardioprotective heat shock response. The present study focuses on the role played by this ubiquitous response in mediating a differential tolerance to acute hypoxic stress. Sprague Dawley rats were exposed to simulated hypoxia equivalent to 223 mmHg pressure, screened on the basis of time taken for onset of a characteristic hyperventilatory response, and categorized as susceptible (<10 min), normal (10-25 min), or tolerant (>25 min). The tolerant animals displayed a significant upregulation of heat shock protein (Hsp) 70/HSPA, evident through immunohistochemical staining of the cardiac tissue. The increased expression of transcription factor heat shock factor-1 led to the downstream activation of other chaperones, including Hsp90/HSPC, Hsp60/HSPD1, and Hsp27/HSPB1. The higher induction of HSPs in tolerant animals contributed to higher nitric oxide synthesis mediated by both endothelial nitric oxide synthase and inducible nitric oxide synthase activation. Conversely, susceptible animals showed significantly higher expression of the proinflammatory markers tumor necrosis factor alpha and nuclear factor kappa-light-chain enhancer of activated B cells in the myocardium. Evaluation of circulatory stress markers identified increased levels of reactive oxygen species, corticosterone and endothelin-1 in the susceptible animals highlighting their vulnerability to hypoxic stress. The heat shock response, through the action of chaperones and enhanced NO generation thus contributes substantially to the ability to sustain survival under acute sub lethal hypoxia.