Protection of stromal cell-derived factor 2 by heat shock protein 72 prevents oxaliplatin-induced cell death in oxaliplatin-resistant human gastric cancer cells

Heat shock protein paradigms in cancer progression: future therapeutic perspectives

Heat-shock proteins (HSPs), also known as stress proteins, are ubiquitously present in all forms of life. They play pivotal roles in protein folding and unfolding, the formation of multiprotein complexes, the transportation and sorting of proteins into their designated subcellular compartments, the regulation of the cell cycle, and signalling processes. These HSPs encompass HSP27, HSP40, HSP70, HSP60, and HSP90, each contributing to various cellular functions. In the context of cancer, HSPs exert influence by either inhibiting or activating diverse signalling pathways, thereby impacting growth, differentiation, and cell division. This article offers an extensive exploration of the functions of HSPs within the realms of pharmacology and cancer biology. HSPs are believed to play substantial roles in the mechanisms underlying the initiation and progression of cancer. They hold promise as valuable clinical markers for cancer diagnosis, potential targets for therapeutic interventions, and indicators of disease progression. In times of cellular stress, HSPs function as molecular chaperones, safeguarding the structural and functional integrity of proteins and aiding in their proper folding. Moreover, HSPs play a crucial role in cancer growth, by regulating processes such as angiogenesis, cell proliferation, migration, invasion, and metastasis.

Identification of novel tumor microenvironment-associated genes in gastric cancer based on single-cell RNA-sequencing datasets

Tumor microenvironment and heterogeneity play vital roles in the development and progression of gastric cancer (GC). In the past decade, a considerable amount of single-cell RNA-sequencing (scRNA-seq) studies have been published in the fields of oncology and immunology, which improve our knowledge of the GC immune microenvironment. However, much uncertainty still exists about the relationship between the macroscopic and microscopic data in transcriptomics. In the current study, we made full use of scRNA-seq data from the Gene Expression Omnibus database (GSE134520) to identify 25 cell subsets, including 11 microenvironment-related cell types. The MIF signaling pathway network was obtained upon analysis of receptor–ligand pairs and cell–cell interactions. By comparing the gene expression in a wide variety of cells between intestinal metaplasia and early gastric cancer, we identified 64 differentially expressed genes annotated as immune response and cellular communication. Subsequently, we screened these genes for prognostic clinical value based on the patients’ follow-up data from The Cancer Genome Atlas. TMPRSS15, VIM, APOA1, and RNASE1 were then selected for the construction of LASSO risk scores, and a nomogram model incorporating another five clinical risk factors was successfully created. The effectiveness of least absolute shrinkage and selection operator risk scores was validated using gene set enrichment analysis and levels of immune cell infiltration. These findings will drive the development of prognostic evaluations affected by the immune tumor microenvironment in GC.

DNAJB8 in small extracellular vesicles promotes Oxaliplatin resistance through TP53/MDR1 pathway in colon cancer

Chemotherapy is one of the most frequently used therapies for the treatment of colon cancer (COAD). However, Oxaliplatin (L-OHP) resistance is a major obstacle to the effective treatment of COAD. Here, we investigated whether DNAJB8, a heat shock protein 40 (HSP40) family protein, could be used for the prognosis and therapy of L-OHP resistance in COAD. Treatment with small interfering RNA targeting DNAJB8 could restore the response to L-OHP in vitro and in vivo. On the mechanism, we demonstrated that DNAJB8 could interact with TP53 and inhibit the ubiquitination degradation of TP53, leading to MDR1 upregulation which promotes colon cancer L-OHP resistance. We found that small extracellular vesicle (sEV)-mediated transfer of DNAJB8 from L-OHP-resistant COAD cells to sensitive cells contributed to L-OHP resistance. A prognostic signature based on the DNAJB8 levels in both tissue and serum showed that COAD patients with high-risk scores exhibited significantly worse overall survival and disease-free survival than patients with low-risk scores. These results indicate that DNAJB8 levels in serum sEVs may serve as a biomarker for COAD. DNAJB8 from sEVs might be a promising therapeutic target for L-OHP resistance and a prognostic predictor of clinical response.

Location, function and role of stromal cell‑derived factors and possible implications in cancer (Review)

Despite improvements in therapy and management, cancer represents and remains a major cause of mortality and morbidity worldwide. Although genetics serve an important role in tumorigenesis and tumour progression, the tumour microenvironment (TME) in solid tumours is also important and has been indicated to contribute to these processes. Stromal cell‑derived factors (SDFs) represent an important family within the TME. The family includes SDF‑1, SDF‑2, SDF2‑like 1 (SDF2L1), SDF‑3, SDF‑4 and SDF‑5. SDF‑1 has been demonstrated to act as a positive regulator in a number of types of tumour, such as oesophago‑gastric, pancreatic, lung, breast, colorectal and ovarian cancer, while the biology and functions of other members of the SDF family, including SDF‑2, SDF2L1, SDF‑4 and SDF‑5, in cancer are different, complex and controversial, and remain mainly unknown. Full identification and understanding of the SDFs across multiple types of cancer is required to elucidate their function and establish potential key targets in cancer.

Generation of Rat Monoclonal Antibodies Specific for Human Stromal Cell-Derived Factor-2

Stromal cell-derived factor-2 (SDF-2) is reportedly involved in multiple endoplasmic reticulum (ER) functions, including the misfolded protein catabolic process, protein glycosylation, and ER protein quality control. However, the precise molecular and cellular functions of SDF-2 remain unknown. Previously, we discovered that SDF-2 mediates acquired resistance to oxaliplatin in human gastric cancer cells. In this study, we have generated SDF-2-specific monoclonal antibodies (mAbs), using the rat medial iliac lymph node method, as a tool to explore novel mechanisms of oxaliplatin resistance. The antibodies detected endogenous human SDF-2 in immunoblotting analyses. In addition, immunoprecipitation analyses revealed the availability of these antibodies for human SDF-2. Thus, these mAbs will be available to elucidate molecular and cellular functions of SDF-2 in 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.

The potential contribution of stromal cell-derived factor 2 (SDF2) in endoplasmic reticulum stress response in severe preeclampsia and labor-onset

Endoplasmic reticulum (ER) stress occurs when the protein folding machinery in the cell is unable to cope with newly synthesized proteins, which results in an accumulation of misfolded proteins in the ER lumen. In response, the cell activates a cellular signaling pathway known as the Unfolded Protein Response (UPR), aiming to restore cellular homeostasis. Activation and exacerbation of the UPR have been described in several human pathologies, including cancer and neurological disorders, and in some gestational diseases such as preeclampsia and gestational diabetes. This review explores the participation of stromal cell-derived factor 2 (SDF2) in UPR pathways, shows new information and discusses its exacerbation regarding protein expression in severe preeclampsia and labor, both of which are associated with ER stress.

HSP72 functionally inhibits the anti-neoplastic effects of HDAC inhibitors

BACKGROUND

The anticancer effects of histone deacetylase inhibitors (HDACi) vary between patients, and their molecular mechanisms remain poorly understood. Previously, we have identified heat shock 70 kDa protein 1A (HSPA1A, also known as HSP72) as the most overexpressed protein in valproic acid (VPA)-resistant cell lines. KNK437, an inhibitor of heat shock proteins, enhanced the cytotoxic effects of not only VPA but also vorinostat, another HDACi. However, the mechanisms underlying the role of HSP72 in resistance against HDACi remain largely unknown.

OBJECTIVE

The purpose of this study was to identify the mechanisms underlying the role of HSP72 in HDACi resistance.

METHODS

We established an HSP72-overexpressing Jurkat cell line and used it to assess the functional role of HSP72 following treatment with the HDACi vorinostat and VPA.

RESULTS

HDACi-induced apoptosis, assessed using annexin V assays, sub-G1 fraction analysis, and PARP cleavage, was significantly lower in HSP72-overexpressing cells than in control cells. The HDACi-induced upregulation in caspase-3, -8, and -9 activity, as well as the HDACi-induced reduction in mitochondrial membrane potential, were also suppressed following HSP72 overexpression. The basal expression levels of Bcl-2, phosphorylated Bad, and XIAP increased in HSP72-overexpressing cells, whereas HDACi-induced Bid truncation and the suppression of Bad expression. Furthermore, vorinostat-induced histone hyperacetylation was also diminished in HSP72-overexpressing cells.

CONCLUSION

These findings clearly demonstrate that HSP72 inhibits HDACi-induced apoptosis.

Comparative proteomic analysis of rats subjected to water immersion and restraint stress as an insight into gastric ulcers

In the present study, comparative proteomic analysis was performed in rats subjected to water immersion-restraint stress (WRS). A total of 26 proteins were differentially expressed and identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Among the 26 differentially expressed protein spots identified, 13 proteins were significantly upregulated under WRS, including pyruvate kinase and calreticulin, which may be closely associated with energy metabolism. In addition, 12 proteins were downregulated under WRS, including hemoglobin subunit β-2 and keratin type II cytoskeletal 8, which may be important in protein metabolism and cell death. Gene Ontology analysis revealed the cellular distribution, molecular function and biological processes of the identified proteins. The mRNA levels of certain differentially expressed proteins were analyzed using fluorescence quantitative polymerase chain reaction analysis. The results of the present study aimed to offer insights into proteins, which are differentially expressed in gastric ulcers in stress, and provide theoretical evidence of a radical cure for gastric ulcers in humans.

Heat Shock Proteins and Cancer

Heat shock proteins (HSPs) constitute a large family of proteins involved in protein folding and maturation whose expression is induced by heat shock or other stressors. The major groups are classified based on their molecular weights and include HSP27, HSP40, HSP60, HSP70, HSP90, and large HSPs. HSPs play a significant role in cellular proliferation, differentiation, and carcinogenesis. In this article we comprehensively review the roles of major HSPs in cancer biology and pharmacology. HSPs are thought to play significant roles in the molecular mechanisms leading to cancer development and metastasis. HSPs may also have potential clinical uses as biomarkers for cancer diagnosis, for assessing disease progression, or as therapeutic targets for cancer therapy.