Inhibition of heat shock protein 90 with AUY922 represses tumor growth in a transgenic mouse model of islet cell neoplasms

A novel combination therapy targets sonic hedgehog signaling by the dual inhibition of HMG-CoA reductase and HSP90 in rats with non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is characterized by liver inflammation, fat accumulation, and collagen deposition. Due to the limited availability of effective treatments, there is a pressing need to develop innovative strategies. Given the complex nature of the disease, employing combination approaches is essential. Hedgehog signaling has been recognized as potentially promoting NASH, and cholesterol can influence this signaling by modifying the conformation of PTCH1 and SMO activity. HSP90 plays a role in the stability of SMO and GLI proteins. We revealed significant positive correlations between Hedgehog signaling proteins (Shh, SMO, GLI1, and GLI2) and both cholesterol and HSP90 levels. Herein, we investigated the novel combination of the cholesterol-lowering agent lovastatin and the HSP90 inhibitor PU-H71 in vitro and in vivo. The combination demonstrated a synergy score of 15.09 and an MSA score of 22.85, as estimated by the ZIP synergy model based on growth inhibition rates in HepG2 cells. In a NASH rat model induced by thioacetamide and a high-fat diet, this combination therapy extended survival, improved liver function and histology, and enhanced antioxidant defense. Additionally, the combination exhibited anti-inflammatory and anti-fibrotic potential by influencing the levels of TNF-α, TGF-β, TIMP-1, and PDGF-BB. This effect was evident in the suppression of the Col1a1 gene expression and the levels of hydroxyproline and α-SMA. These favorable outcomes may be attributed to the combination's potential to inhibit key Hedgehog signaling molecules. In conclusion, exploring the applicability of this combination contributes to a more comprehensive understanding and improved management of NASH and other fibrotic disorders.

Heat-activated nanomedicine formulation improves the anticancer potential of the HSP90 inhibitor luminespib in vitro

The heat shock protein 90 inhibitor, luminespib, has demonstrated potent preclinical activity against numerous cancers. However, clinical translation has been impeded by dose-limiting toxicities that have necessitated dosing schedules which have reduced therapeutic efficacy. As such, luminespib is a prime candidate for reformulation using advanced drug delivery strategies that improve tumor delivery efficiency and limit off-target side effects. Specifically, thermosensitive liposomes are proposed as a drug delivery strategy capable of delivering high concentrations of drug to the tumor in combination with other chemotherapeutic molecules. Indeed, this work establishes that luminespib exhibits synergistic activity in lung cancer in combination with standard of care drugs such as cisplatin and vinorelbine. While our research team has previously developed thermosensitive liposomes containing cisplatin or vinorelbine, this work presents the first liposomal formulation of luminespib. The physico-chemical properties and heat-triggered release of the formulation were characterized. Cytotoxicity assays were used to determine the optimal drug ratios for treatment of luminespib in combination with cisplatin or vinorelbine in non-small cell lung cancer cells. The formulation and drug combination work presented in this paper offer the potential for resuscitation of the clinical prospects of a promising anticancer agent.

HSP90 and Co-chaperones: Impact on Tumor Progression and Prospects for Molecular-Targeted Cancer Therapy

Heat shock protein 90 (HSP90), a highly and unique chaperone, presents as a double-edged sword. It plays an essential role in many physiological and pathological processes, including tumor development. The current review highlights a recent understanding of the roles of HSP90 in molecular mechanisms underlying cancer survival and progression. HSP90 and its client proteins through the regulation of oncoproteins including signaling proteins, receptors, and transcriptional factors involved in tumorigenesis. It also has potential clinical application as diagnostic and prognostic biomarkers for assessing cancer progression. In this way, using HSP90 to develop new anticancer therapeutic agents including HSP90 inhibitors, anti-HSP90 antibody, and HSP90-based vaccines has been promising.

Epigenetic Alterations of Heat Shock Proteins (HSPs) in Cancer

Heat shock proteins (HSPs) are associated with various physiological processes (protein refolding and degradation) involved in the responses to cellular stress, such as cytotoxic agents, high temperature, and hypoxia. HSPs are overexpressed in cancer cells and play roles in their apoptosis, invasion, proliferation, angiogenesis, and metastasis. The regulation or translational modification of HSPs is recognized as a therapeutic target for the development of anticancer drugs. Among the regulatory processes associated with HSP expression, the epigenetic machinery (miRNAs, histone modification, and DNA methylation) has key functions in cancer. Moreover, various epigenetic modifiers of HSP expression have also been reported as therapeutic targets and diagnostic markers of cancer. Thus, in this review, we describe the epigenetic alterations of HSP expression in cancer cells and suggest that HSPs be clinically applied as diagnostic and therapeutic markers in cancer therapy via controlled epigenetic modifiers.

Genetic and pharmacologic abrogation of Snail1 inhibits acinar-to-ductal metaplasia in precursor lesions of pancreatic ductal adenocarcinoma and pancreatic injury

Pancreatic cancer (PDAC) is one of the most dismal of human malignancies. Inhibiting or delaying the progression of precursor lesions of PDAC, pancreatic intraepthial neoplasia (PanINs), to invasive cancer, would be a major step. In the present study, we used a transgenic murine model of pancreatic cancer to evaluate the impact of a conditional knockout of the transcription factor Snail1, a major factor in epithelial-to-mesenchymal transition, on acinar-to-ductal formation and on PanIN progression. By interbreeding conditional LsL-Snail ^floxf/wt ; LsL-Kras ^G12D and Pdx1-Cre strains, we obtained LsL-Kras ^G12D ;Pdx1-Cre(KP) mice, Snail1 heterozygous knockout LsL-Kras ^G12D ; LsL-Snail ^flox/- ;Pdx1-Cre(KPS^het) mice or Snail1 homozygous knockout LsL-Kras ^G12D ;LsL-Snail ^flox/flox ;Pdx1-Cre(KPS) mice. Mice were then followed in a longitudinal study for 2, 4, 6, 8, 10, and 12 months. Furthermore, in mice with a genetic or pharmacological inhibition of Snail1, using the Snail1 inhibitor GN25, a model of pancreatic injury by administration of cerulein was introduced to evaluate ADM formation in this setting. A translational approach with a tissue microarray (TMA) of human PanINs and an in vivo nude mouse platform to test GN25 in human pancreatic adenocarcinoma was then adopted. Quantification of PanINs showed delayed initiation and progression of PanIN lesions at all ages in both homozygous and heterozygous Snail^del1;Pdx-1-Cre;LSL-Kras^G12D/+-Mice. PanINs at TMA revealed snail expression in the majority of cases. GN25 showed growth inhibition in 2/2 human pancreatic adenocarcinomas using a nude mice in vivo platform. Genetic and pharmacologic abrogation of Snail1 signaling in exocrine pancreas impairs development of acinar-to-ductal metaplasia following cerulein-mediated pancreatic injury. The present study suggests a fundamental new approach to delay the progression of PDAC.

WOMEN IN CANCER THEMATIC REVIEW: Systemic therapies in neuroendocrine tumors and novel approaches toward personalized medicine

Neuroendocrine tumors (NETs) are a group of heterogenous neoplasms. Evidence-based treatment options for antiproliferative therapy include somatostatin analogues, the mTOR inhibitor everolimus, the multiple tyrosine kinase inhibitor sunitinib and peptide receptor radionuclide therapy with 177-Lu-octreotate. In the absence of definite predictive markers, therapeutic decision making follows clinical and pathological criteria. As objective response rates with targeted drugs are rather low, and response duration is limited in most patients, numerous combination therapies targeting multiple pathways have been explored in the field. Upfront combination of drugs, however, is associated with increasing toxicity and has shown little benefit. Major advancements in the molecular understanding of NET based on genomic, epigenomic and transcriptomic analysis have been achieved with prognostic and therapeutic impact. New insight into molecular alterations has paved the way to biomarker-driven clinical trials and may facilitate treatment stratification toward personalized medicine in the near future. However, an improved understanding of the complexity of pathway interactions is required for successful treatment. A systems biology approach is one of the tools that may help to achieve this endeavor.

Advances in clinical and basic research of gastroentero-pancreatic neuroendocrine neoplasms

Gastroentero-pancreatic neuroendocrine neoplasms (GEP-NENs) are a group of relatively rare tumors, which mainly originate from the peptidergic neuron and neuroendocrine cells of the gastroentero-pancreatic system. They are characterized by secretion of peptide hormones and neuroendocrine markers (such as synaptic vesicle proteins and chromaffin granule A). Surgery is the most effective therapy for GEP-NENs at early stages. For GEP-NENs at progressive stages, biological target therapies have aroused great interest. Current studies about the molecular basis of biological target therapies have focused on the GEP-NEN gene mutations and related signaling pathways. These studies have led to the clinical application with significant progress in GEP-NEN treatment. In this paper, we review the recent advances in the clinical and basic research of GEP-NENs.

The role of heat shock proteins in cancer

Heat shock proteins (HSPs) are an evolutionary family of proteins that act as molecular chaperones. According to their size they have been classified into the following families; HSP90, HSP70, HSP60, HSP40 and HSP27. They prevent the formation of nonspecific protein aggregates and they assist proteins in the acquisition of their normal architecture. Moreover, HSPs are likely to have anti-apoptotic properties and are actively involved in various processes as tumor cell proliferation, invasion, metastases and death. Notably, these proteins have been reported to be significantly elevated in a plethora of human cancers. Their over-expression has been robustly associated with therapeutic resistance and poor survival. In this way, HSPs may have important therapeutic implications and they can be targeted by specific drugs. In this review, we discuss the influence of HSP27, HSP40, HSP60, HSP70 and HSP90 on human cancers. In addition, we report the existing scientific data on this issue with an effort to highlight the possible future implication of HSPs as tumor biomarkers or drug targets for improving prognosis and treatment of cancer patients around the world.