HSF1 in Translation

Heat Shock Factor 1 as a Prognostic and Diagnostic Biomarker of Gastric Cancer

Identification of effective prognostic and diagnostic biomarkers is needed to improve the diagnosis and treatment of gastric cancer. Early detection of gastric cancer through diagnostic markers can help establish effective treatments. Heat shock factor 1 (HSF1), presented in this review, is known to be regulated by a broad range of transcription factors, including those characterized in various malignant tumors, including gastric cancer. Particularly, it has been demonstrated that HSF1 regulation in various cancers is correlated with different processes, such as cell death, proliferation, and metastasis. Due to the effect of HSF1 on the initiation, development, and progression of various tumors, it is considered as an important gene for understanding and treating tumors. Additionally, HSF1 exhibits high expression in various cancers, and its high expression adversely affects the prognosis of various cancer patients, thereby suggesting that it can be used as a novel, predictive, prognostic, and diagnostic biomarker for gastric cancer. In this review, we discuss the literature accumulated in recent years, which suggests that there is a correlation between the expression of HSF1 and prognosis of gastric cancer patients through public data. Consequently, this evidence also indicates that HSF1 can be established as a powerful biomarker for the prognosis and diagnosis of gastric cancer.

Gold Nanoparticle Approach to the Selective Delivery of Gene Silencing in Cancer-The Case for Combined Delivery?

Gene therapy arises as a great promise for cancer therapeutics due to its potential to silence genes involved in tumor development. In fact, there are some pivotal gene drivers that suffer critical alterations leading to cell transformation and ultimately to tumor growth. In this vein, gene silencing has been proposed as an active tool to selectively silence these molecular triggers of cancer, thus improving treatment. However, naked nucleic acid (DNA/RNA) sequences are reported to have a short lifetime in the body, promptly degraded by circulating enzymes, which in turn speed up elimination and decrease the therapeutic potential of these drugs. The use of nanoparticles for the effective delivery of these silencers to the specific target locations has allowed researchers to overcome this issue. Particularly, gold nanoparticles (AuNPs) have been used as attractive vehicles for the target-specific delivery of gene-silencing moieties, alone or in combination with other drugs. We shall discuss current trends in AuNP-based delivery of gene-silencing tools, considering the promising road ahead without overlooking existing concerns for their translation to clinics.

Regulating the cytoprotective response in cancer cells using simultaneous inhibition of Hsp90 and Hsp70

Both heat shock protein 90 and 70 (Hsp90, Hsp70) are cytoprotective proteins that regulate cell death by stabilizing and folding proteins. Taking a two-pronged approach, involving simultaneous inhibition of Hsp90 and Hsp70, leads to synergistic cell death, which makes this is an appealing clinical therapy.

Upregulation of Nuclear Heat Shock Factor 1 Contributes to Tumor Angiogenesis and Poor Survival in Patients With Non-Small Cell Lung Cancer

BACKGROUND

The aim of this study was to detect the expression of heat shock factor 1 (HSF1) and microvessel density (MVD) in patients with non-small cell lung cancer (NSCLC) and to examine the relevance between HSF1 and angiogenesis, clinicopathologic factors, and prognosis.

METHODS

Immunohistochemical staining was used to examine the level of expression of HSF1 and CD34. MVD was used to detect the number of microvessels by counting CD34(+) endothelial cells. Their relationship with clinicopathologic factors and prognosis in patients with NSCLC was determined using IBM SPSS Statistics, version 19 (SPSS Inc, Chicago, IL).

RESULTS

The level of expression of HSF1 was increased significantly in NSCLC. HSF1 overexpression was observed in 45 patients and was significantly associated with MVD (p = 0.005). The overexpression of HSF1 was not associated with patient sex, age, tumor size, histologic type, or differentiation, but it was significantly associated with node metastasis (p = 0.005) and clinical stage (p = 0.006). HSF1 overexpression and high MVD were significantly associated with poor 5-year disease-free survival (p = 0.001 and p = 0.006, respectively). Patients with HSF1 overexpression and high MVD had a significantly poor overall survival (p = 0.006 and p = 0.019, respectively) and disease-specific survival (p = 0.005 and p = 0.016, respectively). Multivariate analysis showed that HSF1 overexpression was an independent prognosticator for poor overall, disease-specific, and disease-free survival (p = 0.040, p = 0.046, and p = 0.004, respectively).

CONCLUSIONS

Overexpression of HSF1 is common and significantly correlated with tumor angiogenesis in NSCLC. Patients with high HSF1 expression had poorer overall, disease-free, and disease-specific survival. These current findings suggest that HSF1 may serve as a novel prognostic marker and potential therapeutic target molecule for antiangiogenic therapy in patients with NSCLC.

When Cancer Fights Back: Multiple Myeloma, Proteasome Inhibition, and the Heat-Shock Response

Multiple myeloma is a plasma cell malignancy with an estimated 26,850 new cases and 11,240 deaths in 2015 in the United States. Two main classes of agents are the mainstays of therapy-proteasome inhibitors (PI) and immunomodulatory drugs (IMiD). Other new targets are emerging rapidly, including monoclonal antibodies and histone deacetylase (HDAC) inhibitors. These therapeutic options have greatly improved overall survival, but currently only 15% to 20% of patients experience long-term progression-free survival or are cured. Therefore, improvement in treatment options is needed. One potential means of improving clinical options is to target resistance mechanisms for current agents. For example, eliminating the cytoprotective heat-shock response that protects myeloma cells from proteasome inhibition may enhance PI-based therapies. The transcription factor heat-shock factor 1 (HSF1) is the master regulator of the heat-shock response. HSF1 is vital in the proteotoxic stress response, and its activation is controlled by posttranslational modifications (PTM). This review details the mechanisms of HSF1 regulation and discusses leveraging that regulation to enhance PI activity.

N-terminal and C-terminal modulation of Hsp90 produce dissimilar phenotypes

Classic oncogenic heat shock protein 90 (Hsp90) inhibitors target the N-terminus of the protein, triggering a survival mechanism in cancer cells referred to as the heat shock response (HSR).

Heat shock factor 1 is required for migration and invasion of human melanoma in vitro and in vivo

Heat shock factor 1 (HSF1) is a major transactivator of the heat shock response. Recent studies have demonstrated that HSF1 is involved in tumor initiation, maintenance, and progression by regulating the expression of heat shock proteins (HSPs) and other molecular targets. Furthermore, HSF1 was identified as a potent proinvasion oncogene in human melanomas. However, the biological functions of HSF1 in human melanoma remain poorly understood. To determine the functional role of HSF1 in melanoma, we used short hairpin RNA (shRNA) to silence HSF1 in human melanoma cell lines and investigated its effect on cell migration and invasive ability in vitro. We found that HSF1 knockdown led to a marked reduction in migration and invasive ability, and these functions were restored by overexpression of wild-type HSF1. To confirm the in vitro results, we performed subcutaneous xenograft experiments in athymic nude mice. We found that HSF1 was required for melanoma invasion and metastasis, as well as tumorigenic potential in vivo. Overall, these results show that HSF1 is indispensable for melanoma progression and metastasis, and suggests that HSF1 could be a promising therapeutic target for melanoma.