Hsp27 regulates EGF/β-catenin mediated epithelial to mesenchymal transition in prostate cancer

Heat Shock Proteins, a Double-Edged Sword: Significance in Cancer Progression, Chemotherapy Resistance and Novel Therapeutic Perspectives

Heat shock proteins (Hsps) are involved in one of the adaptive mechanisms protecting cells against environmental and metabolic stress. Moreover, the large role of these proteins in the carcinogenesis process, as well as in chemoresistance, was noticed. This review aims to draw attention to the possibilities of using Hsps in developing new cancer therapy methods, as well as to indicate directions for future research on this topic. In order to discuss this matter, a thorough review of the latest scientific literature was carried out, taking into account the importance of selected proteins from the Hsp family, including Hsp27, Hsp40, Hsp60, Hsp70, Hsp90 and Hsp110. One of the more characteristic features of all Hsps is that they play a multifaceted role in cancer progression, which makes them an obvious target for modern anticancer therapy. Some researchers emphasize the importance of directly inhibiting the action of these proteins. In turn, others point to their possible use in the design of cancer vaccines, which would work by inducing an immune response in various types of cancer. Due to these possibilities, it is believed that the use of Hsps may contribute to the progress of oncoimmunology, and thus help in the development of modern anticancer therapies, which would be characterized by higher effectiveness and lower toxicity to the patients.

HSPB1 facilitates chemoresistance through inhibiting ferroptotic cancer cell death and regulating NF-κB signaling pathway in breast cancer

Chemoresistance is one of the major causes of therapeutic failure and poor prognosis for breast cancer patients, especially for triple-negative breast cancer patients. However, the underlying mechanism remains elusive. Here, we identified novel functional roles of heat shock protein beta-1 (HSPB1), regulating chemoresistance and ferroptotic cell death in breast cancer. Based on TCGA and GEO databases, HSPB1 expression was upregulated in breast cancer tissues and associated with poor prognosis of breast cancer patients, which was considered an independent prognostic factor for breast cancer. Functional assays revealed that HSPB1 could promote cancer growth and metastasis in vitro and in vivo. Furthermore, HSPB1 facilitated doxorubicin (DOX) resistance through protecting breast cancer cells from drug-induced ferroptosis. Mechanistically, HSPB1 could bind with Ikβ-α and promote its ubiquitination-mediated degradation, leading to increased nuclear translocation and activation of NF-κB signaling. In addition, HSPB1 overexpression led to enhanced secretion of IL6, which further facilitated breast cancer progression. These findings revealed that HSPB1 upregulation might be a key driver to progression and chemoresistance through regulating ferroptosis in breast cancer while targeting HSPB1 could be an effective strategy against breast cancer.

Dialog beyond the Grave: Necrosis in the Tumor Microenvironment and Its Contribution to Tumor Growth

Damage-associated molecular patterns (DAMPs) are endogenous molecules released from the necrotic cells dying after exposure to various stressors. After binding to their receptors, they can stimulate various signaling pathways in target cells. DAMPs are especially abundant in the microenvironment of malignant tumors and are suspected to influence the behavior of malignant and stromal cells in multiple ways often resulting in promotion of cell proliferation, migration, invasion, and metastasis, as well as increased immune evasion. This review will start with a reminder of the main features of cell necrosis, which will be compared to other forms of cell death. Then we will summarize the various methods used to assess tumor necrosis in clinical practice including medical imaging, histopathological examination, and/or biological assays. We will also consider the importance of necrosis as a prognostic factor. Then the focus will be on the DAMPs and their role in the tumor microenvironment (TME). We will address not only their interactions with the malignant cells, frequently leading to cancer progression, but also with the immune cells and their contribution to immunosuppression. Finally, we will emphasize the role of DAMPs released by necrotic cells in the activation of Toll-like receptors (TLRs) and the possible contributions of TLRs to tumor development. This last point is very important for the future of cancer therapeutics since there are attempts to use TLR artificial ligands for cancer therapeutics.

Atractylenolide I inhibits EMT and enhances the antitumor effect of cabozantinib in prostate cancer via targeting Hsp27

Objective

To investigate the effect of Hsp27 and the inhibitory effect of Atractylenolide I (ATL-1) on the proliferation of prostate cancer cell DU145 and PC-3.

Methods

MTT assay was used to detect the inhibitory effect of silencing Hsp27 and ATL-1 on DU145 and PC-3 proliferation of prostate cancer cells. TUNEL detected the apoptosis rate of prostate cancer cell DU145 and PC-3 after silencing Hsp27 and ATL-1 treated. qRT-PCR was used to detect the changes of apoptosis related genes caspase-3, PARP, Bax and Bcl-2 in prostate cancer cell DU145 and PC-3 after the effect of silencing Hsp27 and ATL-1 treated. At the same time, the antitumor effect of ATL-1 combined with cabozantinib was analyzed.

Results

Hsp27 was highly expressed in human prostate cancer. MTT assay showed that ATL-1 inhibited the proliferation of prostate cancer cells DU145 and PC-3 compared with the control group. TUNEL results showed that silencing Hsp27 and ATL-1 treated could significantly promote the apoptosis of prostate cancer cells DU145 and PC-3 compared with the control group. qRT-PCR results showed that compared with the control group, ATL-1 could promote the expression of caspase-3, PARP and Bax in DU145 and PC-3 prostate cancer cells. Inhibition of Hsp27 by ATL-1 reduced cell viability and induced apoptosis. ATL-1 inhibits the antitumor effect of Hsp27 - enhanced cabozantinib. Hsp27 regulates eIF4E and mediates cell protection.

Conclusion

Silencing Hsp27 inhibits EMT. ATL-1 can inhibit the malignant evolution of prostate cancer cells by inhibiting Hsp27/eIF4E. ATL-1 also enhanced chemosensitization of cabozantinib in prostate cancer.

Alternative ANKHD1 transcript promotes proliferation and inhibits migration in uterine corpus endometrial carcinoma

Alternative splicing (AS) is common in gene expression, and abnormal splicing often results in several cancers. Overall survival-associated splicing events (OS-SEs) have been used to predict prognosis in cancer. The aim of this study was to investigate the presence and function of OS-SEs in uterine corpus endometrial carcinoma (UCEC). Based on TCGA and TCGASpliceSeq databases, gene expression and the AS data of UCEC samples were retrieved. An alternate terminator of ANKHD1 transcripts named ANKHD1-BP3 was found to be significantly related to metastasis and OS in UCEC and significantly associated with HSPB1. The upregulated expression of HSPB1 induced downregulation of ANKHD1-BP3 and promoted tumor metastasis. These findings indicate that HSPB1, a splicing factor, regulates the expression of ANKHD1-BP3 to promote metastasis in UCEC.

The role of heat shock proteins in metastatic colorectal cancer: A review

Heat shock proteins (HSPs) are a large molecular chaperone family classified by their molecular weights, including HSP27, HSP40, HSP60, HSP70, HSP90, and HSP110. HSPs are likely to have antiapoptotic properties and participate actively in various processes such as tumor cell proliferation, invasion, metastases, and death. In this review, we discuss comprehensively the functions of HSPs associated with the progression of colorectal cancer (CRC) and metastasis and resistance to cancer therapy. Taken together, HSPs have numerous clinical applications as biomarkers for cancer diagnosis and prognosis and potential therapeutic targets for CRC and its related metastases.

The Role of Heat Shock Protein 27 in Carcinogenesis and Treatment of Colorectal Cancer

The incidence of colorectal cancer (CRC) has significantly increased in recent decades, which has made this disease an important global health issue. Despite many efforts, there is no useful prognostic or diagnostic biomarker for CRC. Heat shock protein 27 (Hsp27) is one of the most studied members of the Hsp family. It has attracted particular attention in CRC pathogenesis since it is involved in fundamental cell functions for cell survival. Evidence shows that Hsp27 plays important role in CRC progression and metastasis. Hsp27 overexpression has been observed in CRC and is suggested to be associated with CRC's poor prognosis. In the present review, we focus on the current knowledge of the role of Hsp27 in CRC carcinogenesis and the underlying mechanisms. In addition, we discuss the value of targeting Hsp27 in CRC treatment.

Revisiting the Old Data of Heat Shock Protein 27 Expression in Squamous Cell Carcinoma: Enigmatic HSP27, More Than Heat Shock

Initially discovered to be induced by heat shock, heat shock protein 27 (HSP27, also called HSPB1), a member of the small HSP family, can help cells better withstand or avoid heat shock damage. After years of studies, HSP27 was gradually found to be extensively engaged in various physiological or pathophysiological activities. Herein, revisiting the previously published data concerning HSP27, we conducted a critical review of the literature regarding its role in squamous cell carcinoma (SCC) from the perspective of clinicopathological and prognostic significance, excluding studies conducted on adenocarcinoma, which is very different from SCC, to understand the enigmatic role of HSP27 in the tumorigenesis of SCC, including normal mucosa, dysplasia, intraepithelial neoplasm, carcinoma in situ and invasive SCC.

Cross-Talk between Wnt Signaling and Src Tyrosine Kinase

Src, a non-receptor tyrosine kinase, was first discovered as a prototype oncogene and has been shown to critical for cancer progression for a variety of tissues. Src activity is regulated by a number of post-translational modifications in response to various stimuli. Phosphorylations of Src Tyr419 (human; 416 in chicken) and Src Tyr530 (human; 527 in chicken) have been known to be critical for activation and inactivation of Src, respectively. Wnt signaling regulates a variety of cellular functions including for development and cell proliferation, and has a role in certain diseases such as cancer. Wnt signaling is carried out through two pathways: β-catenin-dependent canonical and β-catenin-independent non-canonical pathways as Wnt ligands bind to their receptors, Frizzled, LRP5/6, and ROR1/2. In addition, many signaling components including Axin, APC, Damm, Dishevelled, JNK kinase and Rho GTPases contribute to these canonical and non-canonical Wnt pathways. However, the communication between Wnt signaling and Src tyrosine kinase has not been well reviewed as Src regulates Wnt signaling through LRP6 tyrosine phosphorylation. GSK-3β phosphorylated by Wnt also regulates Src activity. As Wnt signaling and Src mutually regulate each other, it is noted that aberrant regulation of these components give rise to various diseases including typically cancer, and as such, merit a closer look.

The Role of Hsp27 in Chemotherapy Resistance

Heat shock protein (Hsp)-27 is a small-sized, ATP-independent, chaperone molecule that is overexpressed under conditions of cellular stress such as oxidative stress and heat shock, and protects proteins from unfolding, thus facilitating proteostasis and cellular survival. Despite its protective role in normal cell physiology, Hsp27 overexpression in various cancer cell lines is implicated in tumor initiation, progression, and metastasis through various mechanisms, including modulation of the SWH pathway, inhibition of apoptosis, promotion of EMT, adaptation of CSCs in the tumor microenvironment and induction of angiogenesis. Investigation of the role of Hsp27 in the resistance of various cancer cell types against doxorubicin, herceptin/trastuzumab, gemcitabine, 5-FU, temozolomide, and paclitaxel suggested that Hsp27 overexpression promotes cancer cell survival against the above-mentioned chemotherapeutic agents. Conversely, Hsp27 inhibition increased the efficacy of those chemotherapy drugs, both in vitro and in vivo. Although numerous signaling pathways and molecular mechanisms were implicated in that chemotherapy resistance, Hsp27 most commonly contributed to the upregulation of Akt/mTOR signaling cascade and inactivation of p53, thus inhibiting the chemotherapy-mediated induction of apoptosis. Blockage of Hsp27 could enhance the cytotoxic effect of well-established chemotherapeutic drugs, especially in difficult-to-treat cancer types, ultimately improving patients' outcomes.

Small Heat Shock Proteins in Retinal Diseases

This review summarizes the latest findings on small heat shock proteins (sHsps) in three major retinal diseases: glaucoma, diabetic retinopathy, and age-related macular degeneration. A general description of the structure and major cellular functions of sHsps is provided in the introductory remarks. Their role in specific retinal diseases, highlighting their regulation, role in pathogenesis, and possible use as therapeutics, is discussed.

Stromal Fibroblasts Counteract the Caveolin-1-Dependent Radiation Response of LNCaP Prostate Carcinoma Cells

In prostate cancer (PCa), a characteristic stromal–epithelial redistribution of the membrane protein caveolin 1 (CAV1) occurs upon tumor progression, where a gain of CAV1 in the malignant epithelial cells is accompanied by a loss of CAV1 in the tumor stroma, both facts that were correlated with higher Gleason scores, poor prognosis, and pronounced resistance to therapy particularly to radiotherapy (RT). However, it needs to be clarified whether inhibiting the CAV1 gain in the malignant prostate epithelium or limiting the loss of stromal CAV1 would be the better choice for improving PCa therapy, particularly for improving the response to RT; or whether ideally both processes need to be targeted. Concerning the first assumption, we investigated the RT response of LNCaP PCa cells following overexpression of different CAV1 mutants. While CAV1 overexpression generally caused an increased epithelial-to-mesenchymal phenotype in respective LNCaP cells, effects that were accompanied by increasing levels of the 5′-AMP-activated protein kinase (AMPK), a master regulator of cellular homeostasis, only wildtype CAV1 was able to increase the three-dimensional growth of LNCaP spheroids, particularly following RT. Both effects could be limited by an additional treatment with the SRC inhibitor dasatinib, finally resulting in radiosensitization. Using co-cultured (CAV1-expressing) fibroblasts as an approximation to the in vivo situation of early PCa it could be revealed that RT itself caused an activated, more tumor-promoting phenotype of stromal fibroblats with an increased an increased metabolic potential, that could not be limited by combined dasatinib treatment. Thus, targeting fibroblasts and/or limiting fibroblast activation, potentially by limiting the loss of stromal CAV1 seems to be absolute for inhibiting the resistance-promoting CAV1-dependent signals of the tumor stroma.

Heat Shock Protein Beta 1 is a Prognostic Biomarker and Correlated with Immune Infiltrates in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most serious malignancies. The main features of HCC are vascular invasion and drug resistance. Ferroptosis is a novel cell program that is involved in several diseases, such as cancer. Heat shock protein beta 1 (HSPB1) is a major component of heat shock proteins. A recent study showed that HSPB1 could be a new therapeutic target for colorectal cancer with 5-fluorouracil-acquired resistance. However, the functional role of HSPB1 in HCC remains unclear.

Aim

The aim of this study is to clarify HSPB1 expression in HCC and its potential therapeutic and prognostic value.

Methods

We collected data on HSPB1 expression levels in HCC and normal liver tissues from The Cancer Genome Atlas and Gene Expression Omnibus databases. We then validated it using immunohistochemistry (IHC). Receiver operating characteristic and Kaplan–Meier survival curves were used to investigate the role of HSPB1 in the prognosis analysis of HCC. Further, we used the online Search Tool for the Retrieval of Interacting Genes/Proteins website, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes to conduct enrichment analysis and identify the predictive signaling pathways. Meanwhile, we used the TIMER and GSVA package of R (v3.6.3) to analyze the association between HSPB1 and immunocyte infiltration.

Results

Compared to normal tissues, there was differential expression of HSPB1 in pan-cancers. HSPB1 expression was higher in HCC tissues than in normal tissues (p<0.05). There was an evident significant difference between HSPB1 mRNA levels and histologic grade, vascular invasion, and alpha-fetoprotein level (all p values<0.05). Univariate analysis indicated that HCC patients with high HSPB1 levels had shorter overall survival rates than those with low HSPB1 levels (p<0.05). MAPK14, HSPA8, MAPKAPK3, MAPKAPK5, and MAPKAPK2 are essential proteins that interact with HSPB1. There was a significant correlation between HSPB1 expression levels and immune cell infiltration, including CD4⁺ T cells (r=0.203, p<0.05).

Conclusion

High HSPB1 expression is closely associated with a worse prognosis in HCC patients, and HSPB1 may be a target of immunotherapy in HCC.

Interplay of Epidermal Growth Factor Receptor and Signal Transducer and Activator of Transcription 3 in Prostate Cancer: Beyond Androgen Receptor Transactivation

Prostate cancer (PCa) is one of the most common cancers in the world and causes thousands of deaths every year. Conventional therapy for PCa includes surgery and androgen deprivation therapy (ADT). However, about 10-20% of all PCa cases relapse; there is also the further development of castration resistant adenocarcinoma (CRPC-Adeno) or neuroendocrine (NE) PCa (CRPC-NE). Due to their androgen-insensitive properties, both CRPC-Adeno and CRPC-NE have limited therapeutic options. Accordingly, this study reveals the inductive mechanisms of CRPC (for both CRPC-Adeno and CRPC-NE) and fulfils an urgent need for the treatment of PCa patients. Although previous studies have illustrated the emerging roles of epidermal growth factor receptors (EGFR), signal transducer, and activator of transcription 3 (STAT3) signaling in the development of CRPC, the regulatory mechanisms of this interaction between EGFR and STAT3 is still unclear. Our recent studies have shown that crosstalk between EGFR and STAT3 is critical for NE differentiation of PCa. In this review, we have collected recent findings with regard to the involvement of EGFR and STAT3 in malignancy progression and discussed their interactions during the development of therapeutic resistance for PCa.

Hsa_circ_0072309 inhibits proliferation and invasion of glioblastoma

Increasing literature reported that circRNAs play vital roles in the occurrence and progression of GBM and regulate GBM cell proliferation, metastases, and chemosensitivity. However, the expression pattern and function of circRNAs in GBM still need further studies. In our work, hsa_circ_0072309 was remarkably downregulated in GBM. Hsa_circ_0072309 inhibits proliferation and invasion of glioblastoma and affects cytoskeletal of GBM cells. Moreover, we found that the function of hsa_circ_0,072,309 in GBM was associated with HSP27, which was reported to be an important regulator of cell proliferation, invasion and cytoskeletal. Our study provides a novel view of hsa_circ_0072309 in GBM cell proliferation and invasion, indicating that hsa_circ_0072309 may act as a potential therapeutic target for GBM comprehensive treatment.

miR-541-3p enhances the radiosensitivity of prostate cancer cells by inhibiting HSP27 expression and downregulating β-catenin

Heat shock protein 27 (HSP27), a regulator of cell survival, can enhance the resistance of cancer cells to radiotherapy. As microRNA-541-3p (miR-541-3p) was recently predicted to be a putative upstream modulator of HSP27, the present study was designed to investigate the function and mechanism underlying how miR-541-3p modulates the radiosensitivity of prostate cancer (PCa) cells by regulating HSP27. Through quantitative PCR, miR-541-3p was determined to be poorly expressed in PCa tissues relative to normal controls, whereas its expression was enhanced after radiotherapy. Consistently, miR-541-3p expression levels in PCa cells were elevated after radiation. Cell viability and proliferation and apoptosis under radiation were subsequently evaluated in response to loss-of-function of miR-541-3p. It was found that inhibition of miR-541-3p facilitated the viability and proliferation of PCa cells and promoted their apoptosis post radiation, hence reducing the radiosensitivity of LNCaP cells. Dual-luciferase reporter assay identified that miR-541-3p negatively regulated the HSP27 mRNA expression by targeting its 3'-UTR. Meanwhile, miR-541-3p overexpression inhibited the β-catenin expression by targeting HSP27. Furthermore, HSP27 or β-catenin overexpression was noted to significantly reverse the miR-541-3p-mediated changes in the biological functions of PCa cells post radiation, suggesting that HSP27-dependent activation of β-catenin might be the mechanism responsible for the promotive effect of miR-541-3p on radiosensitivity. Collectively, this study suggests that miR-541-3p specifically inhibits the HSP27 expression and downregulates β-catenin, thereby enhancing the radiosensitivity of PCa cells. Our findings highlight the underlying mechanism of the miR-541-3p/HSP27/Wnt/β-catenin axis regarding radiotherapy for PCa.

Adenomyosis-derived extracellular vesicles endow endometrial epithelial cells with an invasive phenotype through epithelial-mesenchymal transition

Extracellular vesicles from highly metastatic tumor cells have been shown to mediate epithelial-mesenchymal transition (EMT)-related events in recipient cells. In endometrial epithelial cells, EMT processes are known to be involved in the development of adenomyosis. We aimed to investigate whether adenomyosis-derived extracellular vesicles (AMEVs) are able to induce an EMT process in endometrial epithelial cells. In this study, AMEVs were isolated from patients with adenomyosis and characterized by transmission electron microscopy, Western blot, and nanoparticle tracking. Primary endometrial epithelial cells (EECs) were derived from normal endometrium tissues from patients with leiomyoma and co-cultured with AMEVs in vitro. AMEV uptake was examined by fluorescence confocal microscopy. The invasion of EECs was confirmed by Transwell assay. Immunohistochemistry, Western blot, and qRT-PCR were performed on EECs to illustrate the expression levels of cytokeratin 19, E-cadherin, vimentin, and zinc finger E-box-binding homeobox 1 (ZEB1). The results indicated that the cellular fluorescence intensity gradually increased after 48 h of co-culture, but decreased after 72 h. After co-culturing with AMEVs for 72 h, EECs expressed significantly lower levels of cytokeratin 19 and E-cadherin, and significantly higher levels of vimentin and ZEB1. Together these results demonstrated that AMEVs induce an EMT process and enhance the invasion of EECs. These changes may contribute to the pathogenesis and progression of adenomyosis.

Her2 promotes early dissemination of breast cancer by suppressing the p38-MK2-Hsp27 pathway that is targetable by Wip1 inhibition

Cancer can metastasize from early lesions without detectable tumors. Despite extensive studies on metastasis in cancer cells from patients with detectable primary tumors, mechanisms for early metastatic dissemination are poorly understood. Her2 promotes breast cancer early dissemination by inhibiting p38, but the downstream pathway in this process was unknown. Using early lesion breast cancer models, we demonstrate that the effect of p38 suppression by Her2 on early dissemination is mediated by MK2 and Hsp27. The early disseminating cells in the MMTV-Her2 breast cancer model are Her2^highp-p38^lowp-MK2^lowp-Hsp27^low, which also exist in human breast carcinoma tissues. Suppression of p38 and MK2 by Her2 reduces MK2-mediated Hsp27 phosphorylation, and unphosphorylated Hsp27 binds to β-catenin and enhances its phosphorylation by Src, leading to β-catenin activation and disseminating phenotypes in early lesion breast cancer cells. Pharmacological inhibition of MK2 promotes, while inhibition of a p38 phosphatase Wip1 suppresses, early dissemination in vivo. These findings identify Her2-mediated suppression of the p38-MK2-Hsp27 pathway as a novel mechanism for cancer early dissemination, and provide a basis for new therapies targeting early metastatic dissemination in Her2⁺ breast cancer.

Reduced LINC00551 expression promotes proliferation and invasion of esophageal squamous cancer by increase in HSP27 phosphorylation

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest cancers, and long noncoding RNAs (lncRNAs) regulate gene expression or activities. This study investigated the role of lncRNA LINC00551 in ESCC development and progression. Three paired ESCC and normal tissues were subjected to next-generation sequencing and we identified 82 upregulated and 60 downregulated lncRNAs, including LINC00551, which was confirmed to markedly downregulated in 78 ESCC tissues and in the Gene Expression Profiling Interactive Analysis data set. Downregulated LINC00551 expression was associated with lymph node metastasis, advanced TNM stage, and tumor size. Moreover, downregulated LINC00551 expression was also associated with poor progression-free survival and overall survival of ESCC patients. In vitro and in vivo, LINC00551 overexpression inhibited ESCC cell proliferation and invasion, whereas knockdown of LINC00551 expression promoted ESCC cell proliferation and invasion. RNA pull-down and mass spectrometry assays identified the potential LINC00551 binding proteins, and HSP27 was a promising LINC00551 targeting proteins after RNA immunoprecipitation assay. At the protein level, LINC00551 bound to and decreased HSP27 phosphorylation, and in turn, downregulated ESCC cell proliferation and invasion. The current study demonstrated the functional significance of LINC00551 in ESCC development, progression, and prognosis. Further study will assess LINC00551 as a novel prognostic marker or therapeutic target for ESCC.

Identification of cofilin-1 as a novel mediator for the metastatic potentials and chemoresistance of the prostate cancer cells

Prostate cancer (PCa) is the most common malignancy among men. Tumor metastasis and chemoresistance contribute to the major cause of the mortality. In this study, we compared the protein profiles of two prostate cancer cell lines with different metastatic potentials, and identified cofilin-1 (CFL1) was one of the most differentially expressed proteins between two cell lines. Further results suggested that cofilin-1 promoted the remodeling of F-actin cytoskeleton, and enhanced the proliferation, migration and invasion of the prostate cancer cells via activation of P38 MAPK signaling pathway. In addition, cofilin-1 elevated the expression and drug efflux activity of multidrug resistance protein 1 (MDR1) by P38 MAPK signaling pathway, resulting in decrease of the adriamycin-induced apoptosis as well as the lytic cell death, and the subsequent resistance against adriamycin. Collectively, cofilin-1 might serve as a novel target candidate for both inhibiting the metastasis and reversing the chemoresistance of PCa.

Molecular Chaperones in Cancer Stem Cells: Determinants of Stemness and Potential Targets for Antitumor Therapy

Cancer stem cells (CSCs) are a great challenge in the fight against cancer because these self-renewing tumorigenic cell fractions are thought to be responsible for metastasis dissemination and cases of tumor recurrence. In comparison with non-stem cancer cells, CSCs are known to be more resistant to chemotherapy, radiotherapy, and immunotherapy. Elucidation of mechanisms and factors that promote the emergence and existence of CSCs and their high resistance to cytotoxic treatments would help to develop effective CSC-targeting therapeutics. The present review is dedicated to the implication of molecular chaperones (protein regulators of polypeptide chain folding) in both the formation/maintenance of the CSC phenotype and cytoprotective machinery allowing CSCs to survive after drug or radiation exposure and evade immune attack. The major cellular chaperones, namely heat shock proteins (HSP90, HSP70, HSP40, HSP27), glucose-regulated proteins (GRP94, GRP78, GRP75), tumor necrosis factor receptor-associated protein 1 (TRAP1), peptidyl-prolyl isomerases, protein disulfide isomerases, calreticulin, and also a transcription heat shock factor 1 (HSF1) initiating HSP gene expression are here considered as determinants of the cancer cell stemness and potential targets for a therapeutic attack on CSCs. Various approaches and agents are discussed that may be used for inhibiting the chaperone-dependent development/manifestations of cancer cell stemness.

Quantitative proteomic analysis of the association between decreasing O‑GlcNAcylation and metastasis in MCF‑7 breast cancer cells

Breast cancer is the most common type of cancer and leading cause of cancer-associated mortality in women worldwide. O-linked N-acetyl glucosaminylation (O-GlcNAcylation) is a dynamic post-translational modification of nuclear, cytoplasmic and mitochondrial proteins. Mounting evidence suggests that abnormal O-GlcNAcylation status is associated with cancer malignancy. In our previous study, it was reported that O-GlcNAc and O-GlcNAc transferase (OGT; an enzyme responsible for the addition of O-GlcNAc) were upregulated in breast cancer tissues and cells. Moreover, O-GlcNAcylation was required for resistance to anoikis and the anchorage-independent growth of breast cancer cells. However, the precise roles of this modification on the development of malignancy are yet to be elucidated. Therefore, in the present study, the effects of inhibiting O-GlcNAc on the malignant transformation of MCF-7 breast cancer cells under different culture conditions were determined, using monolayer (primary growth), anoikis resistance (spheroid growth) and reseeding (secondary growth) to mimic the metastatic process. Decreasing O-GlcNAc levels using small interfering (si)RNA targeting OGT resulted in a reduction in cell viability and invasiveness in anoikis resistant and reseeding conditions. Furthermore, gel-free quantitative proteomics was performed to identify the proteins affected by a reduction of O-GlcNAc. A total of 317 proteins were identified and compared, and the expression of 162 proteins was altered >1.5 fold in the siOGT treated cells compared with the siScamble (siSC) treated cells. Notably, 100 proteins involved in cellular metabolism, cellular localization, stress responses and gene expression were significantly altered in the reseeding condition. Among these differentially expressed proteins, the levels of small nuclear ribonucleoprotein Sm D1 exhibited the largest decrease in expression following knockdown of OGT, and this reduction in expression was associated with a significant decrease in the levels of mTOR expression, a protein which promotes tumor growth and progression. Taken together, the results of the present study demonstrate that decreasing O-GlcNAcylation altered protein expression, and ultimately influenced the metastatic processes, particulary regarding the invasion and reattached growth of MCF-7 breast cancer cells.

Heat Shock Proteins: Agents of Cancer Development and Therapeutic Targets in Anti-Cancer Therapy

Heat shock proteins (HSPs) constitute a large family of molecular chaperones classified by their molecular weights, and they include HSP27, HSP40, HSP60, HSP70, and HSP90. HSPs function in diverse physiological and protective processes to assist in maintaining cellular homeostasis. In particular, HSPs participate in protein folding and maturation processes under diverse stressors such as heat shock, hypoxia, and degradation. Notably, HSPs also play essential roles across cancers as they are implicated in a variety of cancer-related activities such as cell proliferation, metastasis, and anti-cancer drug resistance. In this review, we comprehensively discuss the functions of HSPs in association with cancer initiation, progression, and metastasis and anti-cancer therapy resistance. Moreover, the potential utilization of HSPs to enhance the effects of chemo-, radio-, and immunotherapy is explored. Taken together, HSPs have multiple clinical usages as biomarkers for cancer diagnosis and prognosis as well as the potential therapeutic targets for anti-cancer treatment.

Melanoma migration is promoted by prion protein via Akt-hsp27 signaling axis

Patients with metastatic melanoma have a poorer prognosis. Prion protein (PrP) in melanoma is known to play an important role in cancer cell migration and invasion by interacting with filamin A (FLNa), a cytolinker protein. To investigate if PrP may contribute to cancer cell mobility independent of its binding to FLNa, we knocked out PRNP in M2 melanoma cell, which lacked FLNa expression. We found that deletion of PRNP in M2 significantly reduced its motility. When PRNP was deleted, the level of Akt was decreased. As a consequence, phosphorylation of small heat shock protein (hsp27) was also reduced, which resulted in polymerization of F-actin rendering the cells less migratory. Accordingly, when PrP was re-expressed in PRNP null M2 cells, the mobility of the recurred cells was rescued, so were the expression levels of Akt and phosphorylated hsp27, resulting in a decrease in the polymerization of F-actin. These results revealed that PrP can play a FLNa independent role in cytoskeletal organization and tumor cell migration by modulating Akt-hsp27-F-actin axis.

HSP27 promotes epithelial-mesenchymal transition through activation of the β-catenin/MMP3 pathway in pancreatic ductal adenocarcinoma cells

Background

The precise role of heat shock protein 27 (HSP27), as a type of small molecular protein in HSPs, in pancreatic ductal adenocarcinoma (PDAC) remains to be elucidated. The aim of the present study was to investigate the expression and function of HSP27 in PDAC cells.

Methods

We first detected the expression of HSP27 in PDAC tissues. Combining with the clinical pathology characteristics of PDAC patients, the relationship between them was analyzed. Then, we knocked down HSP27 using short interfering RNA (siRNA) and observed its biological functions using scratch assay and matrigel invasion and migration assays in ASPC-1 and PANC-1 cells. In mechanism, we verified the β-catenin/MMP-3 pathway associated proteins in ASPC-1 and PANC-1 cells.

Results

We found that HSP27 was highly expression in PDAC tissues, and was positively correlated with tumor differentiation, TNM staging and poor prognosis of PDAC patients. In vitro, we down-regulated the expression of HSP27 in ASPC-1 and PANC-1 cells and found that the invasion and migration ability of PDAC cells were significantly depressed, meanwhile, the activation of the β-catenin/MMP-3 pathway was inhibited.

Conclusions

HSP27 may be used as a tumor biomarker for diagnosis of PDAC, and HSP27 can promote the invasion and migration of PDAC by activating the β-catenin/MMP3 Pathway. Therefore, inhibition of HSP27 has therapeutic potential for the treatment of PDAC.

Gene expression analysis of heat-shock proteins and redox regulators reveals combinatorial prognostic markers in carcinomas of the gastrointestinal tract

Heat shock proteins (HSPs) are a large family of ubiquitously expressed proteins with diverse functions, including protein assembly and folding/unfolding. These proteins have been associated with the progression of various gastrointestinal tumours. Dysregulation of cellular redox has also been associated with gastrointestinal carcinogenesis, however, a link between HSPs and dysregulation of cellular redox in carcinogenesis remains unclear. In this study, we analysed mRNA co-expression and methylation patterns, as well as performed survival analysis and gene set enrichment analysis, on gastrointestinal cancer data sets (oesophageal, stomach and colorectal carcinomas) to determine whether HSP activity and cellular redox dysregulation are linked. A widespread relationship between HSPs and cellular redox was identified, with specific combinatorial co-expression patterns demonstrated to significantly alter patient survival outcomes. This comprehensive analysis provides the foundation for future studies aimed at deciphering the mechanisms of cooperativity between HSPs and redox regulatory enzymes, which may be a target for future therapeutic intervention for gastrointestinal tumours.

Enhanced EGF receptor-signaling potentiates TGFβ-induced lens epithelial-mesenchymal transition

The ocular lens is exposed to numerous growth factors that influence its behavior in diverse ways. While many of these, such as FGF and EGF promote normal cell behavior, TGFβ is unique in that it can also induce lens cell pathology, namely, the epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) leading to fibrotic cataract formation. The present study explores how EGF impacts on TGFβ-induced EMT in the lens. LECs in explants prepared from 21-day-old Wistar rats were treated with either 200 pg/ml TGFβ2, 5 ng/ml EGF, or a combination of these, with or without a 2-h pre-treatment of an EGFR inhibitor (PD153035), MEK inhibitor (U0126) or Smad3 inhibitor (SIS3). Co-treatment of LECs with TGFβ2 and EGF, compared with TGFβ2 alone, resulted in a more pronounced elongation and transdifferentiation of the LECs into myofibroblastic cells, with higher protein levels of mesenchymal cell markers (α-SMA and tropomyosin). Combining EGF with a less potent lower dose of TGFβ2 (50 pg/ml) induced LECs to undergo EMT equivalent to treatment with a higher dose of TGFβ2 (200 pg/ml) within 5 days of culture. EGF alone, nor the lower dose of TGFβ2, were able to induce EMT in LECs within 5 days. Co-treatment of LECs with EGF and TGFβ2 induced a temporal shift in the phosphorylation levels of Smad2/3, ERK1/2 and EGFR and changed the expression patterns of downstream EMT target genes, compared to treatment of LECs with either growth factor alone. Inhibition of EGFR-signaling with PD153035 blocked the EMT response induced by co-treatment with EGF and TGFβ2. Taken together, our data demonstrate that EGF can potentiate TGFβ2 activity to enhance EMT in LECs, further highlighting the importance of EGFR-signaling in cataract formation. By directly blocking EGFR signaling, the activity of both EGF and TGFβ2 can be simultaneously reduced, thereby serving as a potential target for cataract prevention.

Epithelial mesenchymal transition and resistance in endocrine-related cancers

Epithelial to mesencyhmal transition (EMT) has a central role in tumor metastasis and progression. EMT is regulated by several growth factors and pro-inflammatory cytokines. The most important role in this regulation could be attributed to transforming growth factor-β (TGF-β). In breast cancer, TGF-β effect on EMT could be potentiated by Fos-related antigen, oncogene HER2, epidermal growth factor, or mitogen-activated protein kinase kinase 5 - extracellular-regulated kinase signaling. Several microRNAs in breast cancer have a considerable role either in potentiation or in suppression of EMT thus acting as oncogenic or tumor suppressive modulators. At present, possibilities to target EMT are discussed but the results of clinical translation are still limited. In prostate cancer, many cellular events are regulated by androgenic hormones. Different experimental results on androgenic stimulation or inhibition of EMT have been reported in the literature. Thus, a possibility that androgen ablation therapy leads to EMT thus facilitating tumor progression has to be discussed. Novel therapy agents, such as the anti-diabetic drug metformin or selective estrogen receptor modulator ormeloxifene were used in pre-clinical studies to inhibit EMT in prostate cancer. Taken together, the results of pre-clinical and clinical studies in breast cancer may be helpful in the process of drug development and identify potential risk during the early stage of that process.

MICAL-L2 potentiates Cdc42-dependent EGFR stability and promotes gastric cancer cell migration

Enhanced migration potential is a common characteristic of cancer cells induced by mechanisms that are incompletely defined. The present study was designed to investigate relationship of a new discovered cytoskeleton regulator MICAL‐L2 and the endogenous epidermal growth factor receptor (EGFR) signalling pathways in gastric cancer cell migration. Increased expression of MICAL‐L2 in gastric cancer cells up‐regulated EGFR protein level, accompanied by the increase of cell migration, whereas silencing MICAL‐L2 down‐regulated EGFR and inhibited cell migration. Expression of MICAL‐L2 was also shown positively correlated with the activation of HSP27/cytoskeleton and HSP27/β‐catenin signalling pathways that provide key mechanisms controlling cell migration. The up‐regulating effect of MICAL‐L2 on EGFR is mediated through a transcription‐independent mechanism that involves inhibiting EGFR protein degradation in lysosome. Further analysis indicated that Cdc42 activation contributed in maintaining the effect of MICAL‐L2 on EGFR stability. Furthermore analysis of clinic specimens revealed increased expression of MICAL‐L2 in carcinoma tissues and a positive correlation between MICAL‐L2 and EGFR expression levels. The above results indicate that MICAL‐L2 potentiates gastric cell migration via inhibiting EGFR degradation in lysosome via a Cdc42‐dependent manner that leads to the activation of EGFR/HSP27 signalling pathways.

FAM46B inhibits cell proliferation and cell cycle progression in prostate cancer through ubiquitination of β-catenin

FAM46B is a member of the family with sequence similarity 46. Little is known about the expression and functional role(s) of FAM46B in prostate cancer (PC). In this study, the expression of FAM46B expression in The Cancer Genome Atlas, GSE55945, and an independent hospital database was measured by bioinformatics and real-time PCR analysis. After PC cells were transfected with siRNA or a recombinant vector in the absence or presence of a β-catenin signaling inhibitor (XAV-939), the expression levels of FAM46B, C-myc, Cyclin D1, and β-catenin were measured by western blot and real-time PCR. Cell cycle progression and cell proliferation were measured by flow cytometry and the CCK-8 assay. The effects of FAM46B on tumor growth and protein expression in nude mice with PC tumor xenografts were also measured. Our results showed that FAM46B was downregulated but that β-catenin was upregulated in patients with PC. FAM46B silencing promoted cell proliferation and cell cycle progression in PC, which were abrogated by XAV-939. Moreover, FAM46B overexpression inhibited PC cell cycle progression and cell proliferation in vitro and tumor growth in vivo. FAM46B silencing promoted β-catenin protein expression through the inhibition of β-catenin ubiquitination. Our data clearly show that FAM46B inhibits cell proliferation and cell cycle progression in PC through ubiquitination of β-catenin.

A little-studied protein may help in early diagnosis and treatment of prostate cancer (PC), one of the most common cancers in men. Because early-stage PC causes few symptoms, many patients are not diagnosed until later stages, when treatment options are limited. New methods for early diagnosis and treatment are actively sought. Proteins in the FAM46 family are known to be involved in many types of cancer. Dongliang Yan at Shanghai Sixth People’s Hospital East and co-workers investigated what role one protein in this family, FAM46B, might play in PC. Analysis of tumor samples showed that FAM46B levels were much lower in PC than in healthy tissues. These changes were linked to another tumor-associated protein, β-catenin. In further tests in mice, artificially increasing FAM46B levels decreased tumor size. These results could improve treatments for PC.

Hsp27 regulates epithelial mesenchymal transition, metastasis and proliferation in colorectal carcinoma

The primary factor associated with poor survival rate in patients with colorectal carcinoma (CRC) is the presence of metastasis. The underlying molecular mechanisms of CRC metastasis are yet to be fully elucidated. The present study investigated the function of heat shock protein 27 (Hsp27) on the invasion and proliferation of CRC cells. The clinical significance of Hsp27 was evaluated using tissue microarray analysis (n=81). Invasion and metastasis assays were used to determine the function of Hsp27 in CRC metastasis in vitro and in vivo using RNA interference and the ectopic expression of Hsp27. The upregulation of Hsp27 has been frequently identified in CRC tissues. Patients with CRC and a high expression level of Hsp27 have a reduced overall survival rate. Silencing Hsp27 inhibited the growth and invasion of CRC cells in vitro and in vivo, whereas ectopic overexpression of Hsp27 promoted the proliferation and invasion of CRC cells in vitro. Furthermore, depletion of Hsp27 expression inhibited the epithelial-to-mesenchymal transition (EMT), whilst ectopic overexpression of Hsp27 induced EMT. The results of the present study indicated that Hsp27 serves an important function in the aggressiveness of CRC through inducing EMT. Hsp27 suppression may represent a potential therapeutic option for the suppression of CRC progression.

A hnRNP K⁻AR-Related Signature Reflects Progression toward Castration-Resistant Prostate Cancer

The major challenge in castration-resistant prostate cancer (CRPC) remains the ability to predict the clinical responses to improve patient selection for appropriate treatments. The finding that androgen deprivation therapy (ADT) induces alterations in the androgen receptor (AR) transcriptional program by AR coregulators activity in a context-dependent manner, offers the opportunity for identifying signatures discriminating different clinical states of prostate cancer (PCa) progression. Gel electrophoretic analyses combined with western blot showed that, in androgen-dependent PCa and CRPC in vitro models, the subcellular distribution of spliced and serine-phosphorylated heterogeneous nuclear ribonucleoprotein K (hnRNP K) isoforms can be associated with different AR activities. Using mass spectrometry and bioinformatic analyses, we showed that the protein sets of androgen-dependent (LNCaP) and ADT-resistant cell lines (PDB and MDB) co-immunoprecipitated with hnRNP K varied depending on the cell type, unravelling a dynamic relationship between hnRNP K and AR during PCa progression to CRPC. By comparing the interactome of LNCaP, PDB, and MDB cell lines, we identified 51 proteins differentially interacting with hnRNP K, among which KLK3, SORD, SPON2, IMPDH2, ACTN4, ATP1B1, HSPB1, and KHDRBS1 were associated with AR and differentially expressed in normal and tumor human prostate tissues. This hnRNP K–AR-related signature, associated with androgen sensitivity and PCa progression, may help clinicians to better manage patients with CRPC.

HSP27 is a partner of JAK2-STAT5 and a potential therapeutic target in myelofibrosis

Heat shock protein 27 (HSP27/HSPB1) is a stress-inducible chaperone that facilitates cancer development by its proliferative and anti-apoptotic functions. The OGX-427 antisense oligonucleotide against HSP27 has been reported to be beneficial against idiopathic pulmonary fibrosis. Here we show that OGX-427 is effective in two murine models of thrombopoietin- and JAKV617F-induced myelofibrosis. OGX-427 limits disease progression and is associated with a reduction in spleen weight, in megakaryocyte expansion and, for the JAKV617F model, in fibrosis. HSP27 regulates the proliferation of JAK2V617F-positive cells and interacts directly with JAK2/STAT5. We also show that its expression is increased in both CD34⁺ circulating progenitors and in the serum of patients with JAK2-dependent myeloproliferative neoplasms with fibrosis. Our data suggest that HSP27 plays a key role in the pathophysiology of myelofibrosis and represents a new potential therapeutic target for patients with myeloproliferative neoplasms.

Myelofibrosis is a chronic degenerative disorder characterized by progressive bone marrow fibrosis. Here, the authors show that the chaperone HSP27 contributes to myelofibrosis via regulation of the JAK2/STAT5 pathway, and that antisense oligonucleotides targeting HSP27 are effective in two mouse models of the disease

Effect of liposome‑mediated HSP27 transfection on collagen synthesis in alveolar type II epithelial cells

To investigate the effect of liposome Lipofectamine® 2000‑mediated HSP27 plasmid transfection in A549 human alveolar type II epithelial cell line on collagen synthesis during transforming growth factor‑β1 (TGF‑β1)‑induced type II epithelial cell transition to myofibroblasts. Cells were transfected with varying ratios of the Lipofectamine® 2000‑mediated heat shock protein 27 (HSP27) plasmid and the transfection efficiency was determined using flow cytometry. The maximum transfection efficacy was confirmed by laser confocal microscopy. HSP gene expression and the most efficient HSP27 plasmid were determined using reverse transcription‑quantitative polymerase chain reaction. Western blot analysis was used to examine HSP27 and collagen expression levels. With a transfection efficiency of 83%, the 8 µg:20 µl ratio of liposome: Plasmid had the highest transfection levels. Among the four different interference sequences in the HSP27 plasmid, the D sequence had the highest interference effect with 70% silencing of the HSP27 gene. The expression of type I and III collagen in TGF‑β1‑induced transition of A549 human alveolar type II epithelial cell line to myofibroblasts was significantly downregulated by the successful transfection with HSP27‑interfering plasmid. The expression of type I and III collagen in the TGF‑β1‑induced transition of A549 cells to myofibroblasts was significantly downregulated by transfection of A549 cells with HSP27 plasmid D‑interfering sequence and optimal ratio of Lipofectamine® 2000 and HSP27 plasmid.

Hsp60 exerts a tumor suppressor function by inducing cell differentiation and inhibiting invasion in hepatocellular carcinoma

Heat shock protein 60 (Hsp60), a typical mitochondrial chaperone, is associated with progression of various cancers. However, its expression and significance in hepatocellular carcinoma (HCC) remain largely unclear. In the present study, the mRNA and protein expression of Hsp60 in HCC tissues were detected by quantitative RT-PCR (n=24), western blot (n=7), and immunohistochemical staining (n=295), respectively. The correlation between Hsp60 expression and clinicopathological characteristics of HCC patient was also analyzed. Meanwhile, the influence of Hsp60 on malignant phenotype of HCC cells was further investigated. We found that expression of Hsp60 was significantly downregulated in HCC tissues compared to peritumor tissues. Hsp60 expression was significantly correlated with serum alpha -foetoprotein (AFP) level and tumor differentiation grade. Moreover, high Hsp60 expression cancer/pericancer (C/P) ratio was associated with a better overall survival rate (P=0.035, n=295). The prognostic implication of Hsp60 in HCC was further confirmed in another cohort of 107 HCC patients (P=0.027). Up-regulation of Hsp60 remarkably induced the cell differentiation and inhibited the invasive potential of HCC in vitro and in vivo. Intriguingly, the down-regulation of Hsp60 significantly impaired mitochondrial biogenesis. Although more data are required to clarify the underling mechanism responsible for function of Hsp60, our results suggested that the effect of Hsp60 on differentiation and invasion of HCC cells might be associated with mitochondrial biogenesis. Collectively, our findings indicated that Hsp60 exerted a tumor suppressor function, and might serve as a potential therapeutic target in the treatment of HCC.

Epithelial-mesenchymal transition in prostate cancer: an overview

Prostate cancer is a main urological disease associated with significant morbidity and mortality. Radical prostatectomy and radiotherapy are potentially curative for localized prostate cancer, while androgen deprivation therapy is the initial systemic therapy for metastatic prostate disease. However, despite temporary response, most patients relapse and evolve into castration resistant cancer.

Epithelial-mesenchymal transition (EMT) is a complex gradual process that occurs during embryonic development and/or tumor progression. During this process, cells lose their epithelial characteristics and acquire mesenchymal features. Increasing evidences indicate that EMT promotes prostate cancer metastatic progression and it is closely correlated with increased stemness and drug resistance.

In this review, we discuss the main molecular events that directly or indirectly govern the EMT program in prostate cancer, in order to better define the role and the mechanisms underlying this process in prostate cancer progression and therapeutic resistance.

The clinicopathological and prognostic value of HSP27 in hepatocellular carcinoma: a systematic review and meta-analysis

Background

In the recent past, there is increasing evidence demonstrating that HSP27 plays a key role in tumor progression. However, the relationship between HSP27 expression and the clinicopathological features of hepatocellular carcinoma (HCC), as well as its prognostic value in HCC patients remain controversial. Accordingly, we conducted a meta-analysis to assess the correlation between HSP27 expression and HCC, and determine the prognostic value of HSP27 in HCC.

Methods

The data included clinicopathological features and survival information extracted from the published literature in the databases PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, and Wan Fang. The pooled odds ratios and hazard ratios with 95% CIs were calculated using Forest plot analysis.

Results

The meta-analysis results indicated that the positive HSP27 expression was significantly correlated with HCC incidence, tumor differentiation, and α-fetoprotein level in patients with HCC. However, the expression of HSP27 was not associated with metastasis, hepatitis B virus surface antigen, gender, tumor size, TNM stage, and vascular invasion. Additionally, HSP27 expression indicated a poor overall survival rate, but it was not related to disease-free survival rate.

Conclusion

This meta-analysis revealed that HSP27 may play a key role in the development of HCC and could be a reliable biomarker for the prognosis of patients with HCC. However, additional high-quality research is needed to support the results.

EGF induces epithelial-mesenchymal transition and cancer stem-like cell properties in human oral cancer cells via promoting Warburg effect

"Warburg effect", the enhanced glycolysis or aerobic glycolysis, confers cancer cells the ability to survive and proliferate even under stressed conditions. In this study, we explored the role of epidermal growth factor (EGF) in orchestrating Warburg effect, the epithelial-mesenchymal transition (EMT) process, and the acquisition of cancer stem-like cell properties in human oral squamous cell carcinoma (OSCC) cells. Our results showed that EGF induces EMT process in OSCC cells, which correlates with the acquisition of cancer stem-like properties, including the enrichment of CD44+/CD24- population of cancer cells and an increased expression of CSC-related genes, aldehyde dehydrogenase-1 (ALDH1) and Bmi-1. We also showed that EGF concomitantly enhanced L-lactate production, while blocking glycolysis by 2-deoxy-D-glucose (2-DG) robustly reversed EGF-induced EMT process and CSC-like properties in OSCC cells. Mechanistically, we demonstrated that EGF promoted EMT process and CSC generation through EGFR/PI3K/HIF-1α axis-orchestrated glycolysis. Using an orthotopic tumor model of human OSCC (UM-SCC1) injected in the tongue of BALB/c nude mice, we showed that treatment with 2-DG in vivo significantly inhibited the metastasis of tumor cells to the regional cervical lymph nodes and reduced the expression of ALDH1 and vimentin in both in situ tumors and tumor cell-invaded regional lymph nodes. Taken together, these findings have unveiled a new mechanism that EGF drives OSCC metastasis through induction of EMT process and CSC generation, which is driven by an enhanced glycolytic metabolic program in OSCC cells.

Role of Krüppel-like factor 4 and heat shock protein 27 in cancer of the larynx

Late detection and lack of standard treatment strategies in larynx cancer patients result in high levels of mortality and poor prognosis. Prognostic stratification of larynx cancer patients based on molecular prognostic tumor biomarkers may lead to more efficient clinical management. Krüppel-like factor 4 (KLF4) and Heat Shock Protein 27 (HSP27) have an important role in tumorigenesis and are considered promising candidate biomarkers for various types of cancer. However, their role in larynx carcinoma remains to be elucidated. The present study aimed to determine KLF4 and HSP27 expression profiles in laryngeal tumors. The protein and mRNA expression levels of KLF4 and HSP27 were evaluated by immunohistochemical and reverse transcription-polymerase chain reaction analyses in 44 larynx carcinoma samples and 21 normal tissue samples, and then correlated with clinical characteristics. A differential expression of KLF4 and HSP27 was observed between normal and tumor tissues. The protein and mRNA expression levels of KLF4 were significantly decreased in larynx squamous cell carcinoma (LSCC) compared with normal tissue, whereas HSP27 was significantly overexpressed in tumor tissues compared with normal tissues, at the protein and mRNA levels. KLF4 expression decreased gradually with tumor progression whereas HSP27 expression increased. A significant difference was observed between stages I and IV. KLF4 and HSP27 exhibit opposite functions and roles in the carcinogenic process of LSCC. Their role in laryngeal cancer initiation and progression emphasizes their use as potential future targets for prognosis and treatment. KLF4 and HSP27 expression levels may act as potential biomarkers in patients with cancer of the larynx.

Expression of Heat Shock Protein-27 (Hsp27) and P38MAPK in Esophageal Squamous Cell Carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is a worldwide concern. This study looked at the relationship between the expression of differential proteins and the clinicopathological data and survival rate of ESCC patients to identify potential tumor markers for the growth and metastasis of ESCC.

Material/Methods

This study included 162 patients who underwent surgical excision for management of ESCC. Fresh ESCC tissue and adjacent normal tissue specimens were collected. Protein expressions were detected by western blotting. The expression of Hsp27 and P38MAPK were detected by immunohistochemistry in formalin-fixed paraffin embedded primary tissue specimens.

Results

The rate of positive Hsp27 and P38MAPK expression in ESCC tissue were higher than in normal esophageal tissue (p<0.05). The expression of P38MAPK was related to the depth of infiltration (p<0.05). The expression of Hsp27 was correlated with lymph node metastasis (p<0.05), but not with age, depth of infiltration, or tumor size. ROC were plotted to estimate the significance of the diagnosis: for Hsp27, AUC=0.735 (p<0.05), for P38MAPK, AUC=0.882 (p<0.05).

Conclusions

The expression of Hsp27 and P38MAPK plays a role in ESCC development. Hsp27 and P38MAPK could be used as prognostic factors in ESCC.

EGF-induced urokinase plasminogen activator receptor promotes epithelial to mesenchymal transition in human gastric cancer cells

Epidermal growth factor (EGF) signaling has been shown to induce epithelial to mesenchymal transition (EMT) in many types of cancer cells. However, the molecular mechanism of EGF-induced EMT in gastric cancer remains largely unknown. In the present study, we found that human gastric cancer cell lines SGC-7901 and BGC-823 underwent EMT phenotypic changes upon exposure to EGF. The induction of EMT was consistent with aggressive characteristics such as increased cell migration, invasion and clonogenic growth. Additionally, EGF stimulation also led to the upregulation of urokinase plasminogen activator receptor (uPAR) both at mRNA and protein levels. Knockdown of uPAR by siRNA significantly attenuated EMT induction by EGF in SGC-7901 and BGC-823 cells. Furthermore, EGF increased ERK1/2 activity and blocking ERK1/2 signaling with its inhibitor, U0126, markedly inhibited EGF-induced uPAR expression and consequently EMT. Collectively, the present study demonstrated that EGF induced aggressiveness of gastric cancer cells by activating EMT, which involved the activation of the ERK1/2 pathway and, subsequently, uPAR expression.

Exposure to febrile-range hyperthermia potentiates Wnt signalling and epithelial-mesenchymal transition gene expression in lung epithelium

BACKGROUND

As environmental and body temperatures vary, lung epithelial cells experience temperatures significantly different from normal core temperature. Our previous studies in human lung epithelium showed that: (i) heat shock accelerates wound healing and activates profibrotic gene expression through heat shock factor-1 (HSF1); (ii) HSF1 is activated at febrile temperatures (38-41 °C) and (iii) hypothermia (32 °C) activates and hyperthermia (39.5 °C) reduces expression of a subset of miRNAs that target protein kinase-Cα (PKCα) and enhance proliferation.

METHODS

We analysed the effect of hypo- and hyperthermia exposure on Wnt signalling by exposing human small airway epithelial cells (SAECs) and HEK293T cells to 32, 37 or 39.5 °C for 24 h, then analysing Wnt-3a-induced epithelial-mesenchymal transition (EMT) gene expression by qRT-PCR and TOPFlash reporter plasmid activity. Effects of miRNA mimics and inhibitors and the HSF1 inhibitor, KNK437, were evaluated.

RESULTS

Exposure to 39.5 °C for 24 h increased subsequent Wnt-3a-induced EMT gene expression in SAECs and Wnt-3a-induced TOPFlash activity in HEK293T cells. Increased Wnt responsiveness was associated with HSF1 activation and blocked by KNK437. Overexpressing temperature-responsive miRNA mimics reduced Wnt responsiveness in 39.5 °C-exposed HEK293T cells, but inhibitors of the same miRNAs failed to restore Wnt responsiveness in 32 °C-exposed HEK293T cells.

CONCLUSIONS

Wnt responsiveness, including expression of genes associated with EMT, increases after exposure to febrile-range temperature through an HSF1-dependent mechanism that is independent of previously identified temperature-dependent miRNAs. This process may be relevant to febrile fibrosing lung diseases, including the fibroproliferative phase of acute respiratory distress syndrome (ARDS) and exacerbations of idiopathic pulmonary fibrosis (IPF).

Targeting Lyn regulates Snail family shuttling and inhibits metastasis

The acquisition of an invasive phenotype by epithelial cells occurs through a loss of cellular adhesion and polarity, heralding a multistep process that leads to metastatic dissemination. Since its characterization in 1995, epithelial-mesenchymal transition (EMT) has been closely linked to the metastatic process. As a defining aspect of EMT, loss of cell adhesion through downregulation of E-cadherin is carried out by several transcriptional repressors; key among them the SNAI family of transcription factors. Here we identify for the first time that Lyn kinase functions as a key modulator of SNAI family protein localization and stability through control of the Vav-Rac1-PAK1 (Vav-Rac1-p21-activated kinase) pathway. Accordingly, targeting Lyn in vitro reduces EMT and in vivo reduces metastasis of primary tumors. We also demonstrate the clinical relevance of targeting Lyn as a key player controlling EMT; patient samples across many cancers revealed a strong negative correlation between Lyn and E-cadherin, and high Lyn expression in metastatic tumors as well as metastasis-prone primary tumors. This work reveals a novel pancancer mechanism of Lyn-dependent control of EMT and further underscores the role of this kinase in tumor progression.

Heat shock protein 27 is a potential indicator for response to YangZheng XiaoJi and chemotherapy agents in cancer cells

Heat shock protein 27 (HSP27) is a member of the heat shock protein family which has been linked to tumour progression and, most interestingly, to chemotherapy resistance in cancer patients. The present study examined the potential interplay between HSP27 and YangZheng XiaoJi, a traditional Chinese medicine used in cancer treatment. A range of cell lines from different tumour types including pancreatic, lung, gastric, colorectal, breast, prostate and ovarian cancer (both wild-type and resistant) were used. Levels and activation of HSP27 and its potential associated signalling pathways were evaluated by protein array and western blotting. Knockdown of HSP27 in cancer cells was achieved using siRNA. Localisation and co-localisation of HSP27 and other proteins were carried out by immunofluorescence. Cell growth and migration were evaluated in their response to a range of chemotherapeutic agents. The present study first identified, by way of protein array, that YangZheng XiaoJi was able to inhibit the phosphorylation of HSP27 protein in cancer cells. We further demonstrated that HSP27, which is co-localised with caspase-9, can be blocked from localising in focal adhesions and co-localising with caspase-9 by YangZheng XiaoJi. The study also demonstrated that YangZheng XiaoJi was able to sensitise cancer cells including those cells that were resistant to chemotherapy, to chemotherapeutic agents. Finally, knocking down HSP27 markedly reduced the migration of cancer cells and increased the sensitivity of cancer cells to the inhibitory effect on cellular migration by YangZheng XiaoJi. YangZheng XiaoJi can act as an agent in first sensitising cancer cells to chemotherapy and secondly to overcome, to some degree, chemoresistance when used in an appropriate fashion in patients who have active HSP27.

Molecular chaperone Hsp27 regulates the Hippo tumor suppressor pathway in cancer

Heat shock protein 27 (Hsp27) is a molecular chaperone highly expressed in aggressive cancers, where it is involved in numerous pro-tumorigenic signaling pathways. Using functional genomics we identified for the first time that Hsp27 regulates the gene signature of transcriptional co-activators YAP and TAZ, which are negatively regulated by the Hippo Tumor Suppressor pathway. The Hippo pathway inactivates YAP by phosphorylating and increasing its cytoplasmic retention with the 14.3.3 proteins. Gain and loss of function experiments in prostate, breast and lung cancer cells showed that Hsp27 knockdown induced YAP phosphorylation and cytoplasmic localization while overexpression of Hsp27 displayed opposite results. Mechanistically, Hsp27 regulates the Hippo pathway by accelerating the proteasomal degradation of ubiquitinated MST1, the core Hippo kinase, resulting in reduced phosphorylation/activity of LATS1 and MOB1, its downstream effectors. Importantly, our in vitro results were supported by data from human tumors; clinically, high expression of Hsp27 in prostate tumors is correlated with increased expression of YAP gene signature and reduced phosphorylation of YAP in lung and invasive breast cancer clinical samples. This study reveals for the first time a link between Hsp27 and the Hippo cascade, providing a novel mechanism of deregulation of this tumor suppressor pathway across multiple cancers.

Regulation of epithelial-mesenchymal transition through epigenetic and post-translational modifications

The epithelial to mesenchymal transition (EMT) is a biological process in which a non-motile epithelial cell changes to a mesenchymal phenotype with invasive capacities. This phenomenon has been well documented in multiple biological processes including embryogenesis, fibrosis, tumor progression and metastasis. The hallmark of EMT is the loss of epithelial surface markers, most notably E-cadherin, and the acquisition of mesenchymal markers including vimentin and N-cadherin. The downregulation of E-cadherin during EMT can be mediated by its transcriptional repression through the binding of EMT transcription factors (EMT-TFs) such as SNAIL, SLUG and TWIST to E-boxes present in the E-cadherin promoter. Additionally, EMT-TFs can also cooperate with several enzymes to repress the expression of E-cadherin and regulate EMT at the epigenetic and post- translational level. In this review, we will focus on epigenetic and post- translational modifications that are important in EMT. In addition, we will provide an overview of the various therapeutic approaches currently being investigated to undermine EMT and hence, the metastatic progression of cancer as well.

A Targetable Molecular Chaperone Hsp27 Confers Aggressiveness in Hepatocellular Carcinoma

Heat shock protein 27 (Hsp27) is an ATP-independent molecular chaperone and confers survival advantages and resistance to cancer cells under stress conditions. The effects and molecular mechanisms of Hsp27 in HCC invasion and metastasis are still unclear. In this study, hepatocellular carcinoma (HCC) tissue array (n = 167) was used to investigate the expression and prognostic relevance of Hsp27 in HCC patients. HCC patients with high expression of Hsp27 exhibited poor prognosis. Overexpression of Hsp27 led to the forced invasion of HCC cells, whereas silencing Hsp27 attenuated invasion and metastasis of HCC cells in vitro and in vivo. We revealed that Hsp27 activated Akt signaling, which in turn promoted MMP2 and ITGA7 expression and HCC metastasis. We further observed that targeting Hsp27 using OGX-427 obviously suppressed HCC metastasis in two metastatic models. These findings indicate that Hsp27 is a useful predictive factor for prognosis of HCC and it facilitates HCC metastasis through Akt signaling. Targeting Hsp27 with OGX-427 may represent an attractive therapeutic option for suppressing HCC metastasis.