Molecular chaperones in DNA repair mechanisms: Role in genomic instability and proteostasis in cancer

Disrupting the Hsp90-Cdc37 axis: a selective strategy for targeting oncogenic kinases in cancer

Heat shock protein 90 (Hsp90) is a crucial molecular chaperone responsible for the maturation and stabilization of a wide range of client proteins, many of which are key drivers of oncogenic signaling. While traditional Hsp90 inhibitors targeting its ATPase activity have demonstrated antitumor potential, their clinical progress has been limited by issues such as low selectivity, toxicity, and the induction of cytoprotective heat shock responses. An alternative strategy focuses on disrupting the specific protein-protein interaction between Hsp90 and its kinase-specific co-chaperone, cell division cycle 37 (Cdc37), thereby selectively destabilizing oncogenic kinases without broadly impairing chaperone function. This review discusses the structural insights into the Hsp90-Cdc37 interface, recent advances in the discovery of small molecule inhibitors, peptides, peptidomimetics, and natural products such as celastrol, platycodin D, and withaferin A that effectively disrupt this interaction. Mechanistic studies reveal that disruption leads to targeted degradation of kinase clients, inhibition of key survival pathways including AKT and ERK signaling, induction of apoptosis, and sensitization to other therapeutic agents, all while minimizing activation of the heat shock response. Despite challenges related to targeting dynamic PPI surfaces, optimizing drug-like properties, and validating clinical biomarkers, the therapeutic advantages of this strategy are significant. Hsp90-Cdc37 disruptors represent a promising frontier in precision oncology, offering a refined, selective, and less toxic approach to targeting cancer cell survival networks. Continued multidisciplinary research is expected to drive these agents toward successful clinical translation.

Role of HSP40 proteins in genome maintenance, insulin signaling and cancer therapy

The DnaJ heat shock protein family (HSP40) is the biggest chaperone family in mammalian cells, mainly functioning as cochaperone of HSP70 to maintain proteostasis and cellular homeostasis under both normal and stressful conditions. Although the functions of HSP70s have been extensively studied in diverse biological pathways and senesces including genome maintenance, HSP40s' biological functions at basal state or in response to exogenous insults remain largely under-investigated. Emerging evidence shows that HSP40 proteins participate in genome maintenance pathways and modulate cancer therapy efficacy. This review aims to summarize recent progresses regarding HSP40's functions in genome maintenance and cancer therapy, and provides hints for future studies in the field.

The function of chaperones in the radioresistance of glioblastoma: a new insight into the current knowledge

Radiotherapy remains a cornerstone of brain tumor treatment; however, its effectiveness is frequently undermined by the development of radioresistance. This review highlights the pivotal role of molecular chaperones in promoting radioresistance and explores the potential to increase radioresistance in brain cancers, particularly glioblastoma (GBM). Among chaperones, heat shock proteins (HSPs), such as HSP70 and HSP90, have been identified as key contributors to radioresistance, acting through mechanisms that include the maintenance of protein homeostasis, enhancement of DNA repair processes, and protection of cancer stem cells. Specifically, HSP70 and HSP90 are crucial in stabilizing oncogenic proteins and preventing apoptosis, thus enabling tumor survival during radiotherapy. Also, HSP27 and GRP78 are involved in the radioresistance of brain tumors mainly by suppressing cell death and enhancing tumor stem cell propagation. Emerging evidence also suggests that targeting these chaperones, in combination with radiotherapy, can enhance tumor radiosensitivity, offering promising therapeutic strategies. Recent studies have revealed novel aspects of chaperone-mediated autophagy and interaction with non-coding RNAs, providing deeper insights into the molecular mechanisms underlying radioresistance. This review also addresses the potential of combining chaperone-targeted therapies, such as HSP90 inhibitors, with radiotherapy to overcome resistance. Ultimately, understanding these mechanisms may pave the way for innovative clinical applications and personalized therapeutic approaches in brain tumor treatment.

Proteomics for Biomarker Discovery in Gynecological Cancers: A Systematic Review

The present study aims to summarize the current biomarker landscape in gynecological cancers (GCs) and incorporate bioinformatics analysis to highlight specific biological processes. The literature was retrieved from PubMed, Web of Science, Embase, Scopus, Ovid Medline, and Cochrane Library. The final search was conducted on December 7, 2022. Prospective registration was completed with the PROSPERO with registration number CRD42023477145. This systematic review covered proteomic research on biomarkers for cervical, endometrial, and ovarian cancers. The PANTHER classification system was used to classify the shortlisted candidate biomarkers (CBs), and the STRING database was utilized to visualize protein-protein interaction networks. A total of 23 articles were included in this systematic review. Consistently regulated CBs in the GCs include collagen alpha-2(I) chain, collagen alpha-1(III) chain, collagen alpha-2(V) chain, calreticulin, protein disulfide-isomerase A3, heat shock protein family A (Hsp70) member 5, prolyl 4-hydroxylase, beta polypeptide, fibrinogen alpha chain, fibrinogen gamma chain, apolipoprotein B-100, apolipoprotein C-IV, and apolipoprotein M. In conclusion, collagens, fibrinogens, chaperones, and apolipoproteins were revealed to be replicated in GCs and to be regulated consistently. These CBs contribute to GC etiology and physiology by participating in collagen fibril organization, blood coagulation, protein folding in endoplasmic reticulum, and lipid transporter activity.

Dissecting the functional significance of HSP90AB1 and other heat shock proteins in countering glioblastomas and ependymomas using omics analysis and drug prediction using virtual screening

Heat shock proteins (HSPs) are the evolutionary family of proteins that are highly conserved and present widely in various organisms and play an array of important roles and cellular functions. Currently, very few or no studies are based on the systematic analysis of the HSPs in Glioblastoma (GBMs) and ependymomas. We performed an integrated omics analysis to predict the mutual regulatory differential HSP signatures that were associated with both glioblastoma and ependymomas. Further, we explored the various common dysregulated biological processes operating in both the tumors, and were analyzed using functional enrichment, gene ontology along with the pathway analysis of the predicted HSPs. We established an interactome network of protein-protein interaction (PPIN) to identify the hub HSPs that were commonly associated with GBMs and ependymoma. To understand the mutual molecular mechanism of the HSPs in both malignancies, transcription factors, and miRNAs overlapping with both diseases were explored. Moreover, a transcription factor-miRNAs-HSPs coregulatory network was constructed along with the prediction of potential candidate drugs that were based on perturbation-induced gene expression analysis. Based on the RNA-sequencing data, HSP90AB1 was identified as the most promising target among other predicted HSPs. Finally, the ranking of the drugs was arranged based on various drug scores. In conclusion, this study gave a spotlight on the mutual targetable HSPs, biological pathways, and regulatory signatures associated with GBMs and ependymoma with an improved understanding of crosstalk involved. Additionally, the role of therapeutics was also explored against HSP90AB1. These findings could potentially be able to explain the interplay of HSP90AB1 and other HSPs within these two malignancies.

Targeting Heat Shock Proteins in Malignant Brain Tumors: From Basic Research to Clinical Trials

Heat shock proteins (HSPs) are conservative and ubiquitous proteins that are expressed both in prokaryotic and eukaryotic organisms and play an important role in cellular homeostasis, including the regulation of proteostasis, apoptosis, autophagy, maintenance of signal pathways, protection from various stresses (e.g., hypoxia, ionizing radiation, etc.). Therefore, HSPs are highly expressed in tumor cells, including malignant brain tumors, where they also associate with cancer cell invasion, metastasis, and resistance to radiochemotherapy. In the current review, we aimed to assess the diagnostic and prognostic values of HSPs expression in CNS malignancies as well as the novel treatment approaches to modulate the chaperone levels through the application of inhibitors (as monotherapy or in combination with other treatment modalities). Indeed, for several proteins (i.e., HSP10, HSPB1, DNAJC10, HSPA7, HSP90), a direct correlation between the protein level expression and poor overall survival prognosis for patients was demonstrated that provides a possibility to employ them as prognostic markers in neuro-oncology. Although small molecular inhibitors for HSPs, particularly for HSP27, HSP70, and HSP90 families, were studied in various solid and hematological malignancies demonstrating therapeutic potential, still their potential was not yet fully explored in CNS tumors. Some newly synthesized agents (e.g., HSP40/DNAJ inhibitors) have not yet been evaluated in GBM. Nevertheless, reported preclinical studies provide evidence and rationale for the application of HSPs inhibitors for targeting brain tumors.