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Objective To investigate the effects of Ganetespib and Pemetrexed on the proliferation, apoptosis and related signaling pathways of human lung adenocarcinoma cells in vitro. Methods Human lung adenocarcinoma cells HCC827, H1975, and A549 were divided into groups (Ganetespib group, pemetrexed group, combined treatment group), and a control group (DMSO 0.2%) was set up. After culturing for 48 hours, the Cell Titer-Glo (CTG) method was used to detect the inhibitory effects of cell proliferation in vitro, and Western blot was used to detect the expression levels of Akt, p-Akt, and Bcl-2 proteins in cells. The apoptosis experiment was used to detect the apoptosis rate, and RNA-seq was used to detect the effects of the two drugs on the transcription level of the HCC827 cell line. Results The inhibitory effects of cell proliferation were as follows: Ganetespib > pemetrexed (P < 0.001), and the inhibitory effect was enhanced when the two drugs were combined (P < 0.0001) ; the apoptosis rate was as follows: Ganetespib > pemetrexed (P < 0.05), and the apoptosis rate of HCC827 cells increased when the two drugs were combined; the phosphorylation level of Akt protein was lower in the Ganetespib group (P < 0.05), and the phosphorylation level of Akt protein was higher in the pemetrexed group (P < 0.05), and the results of the combined treatment group were similar to those of the Ganetespib group, and Bcl-2 protein was only downregulated in A549 cells (P < 0.01) ; the two drugs had an effect on the gene transcription level of the HCC827 cell line, with 102 upregulated differentially expressed genes and 27 downregulated genes in the Ganetespib group, 53 upregulated differentially expressed genes and 8 downregulated genes in the pemetrexed group. Conclusion The combination of Ganetespib and pemetrexed can significantly inhibit the proliferation of lung adenocarcinoma cells HCC827, H1975, and A549, induce cell apoptosis. The molecular mechanism may be through the inhibition of lung adenocarcinoma cell proliferation by protein phosphorylation in the PI3K/AKT signaling pathway. The transcriptome of HCC827 cells was affected by the combination therapy. The combined treatment can enhance the inhibition of lung adenocarcinoma cell proliferation to some extent, and the specific mechanism needs further research. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer cells secrete Hsp90, a protein that, inside of cells, regulates the function of hundreds of proteins, but outside of cells, extracellular Hsp90 (eHsp90) can activate a subset of proteins that promote invasion, the first step of metastasis. Blocking eHsp90 in mouse models inhibits metastasis, and we sought to understand how this occurs. Prior studies have predominantly focused on eHsp90 in cancer invasion within the immediate vicinity of the primary tumor, specifically its role in invading outside the epithelial compartment. However, eHsp90's role in cancer invasion across the extended connective tissue after the cells have crossed the boundary of the epithelial compartment remains unknown. We show here that eHsp90 directly binds to and aligns Collagen-1 fibers, a major structural component of connective tissues, which, when aligned, form highways that allow efficient cancer migration. Our study suggests that the Hsp90 dimer, in its open state, binds to Collagen-1 molecules to align the fibers, which results in enhanced breast cancer invasion through the Collagen-1 matrix. Knowing this could help us propose experiments to test eHsp90 inhibitors for therapeutically targeting metastatic breast cancer. Cancer cell-secreted eHsp90 binds and activates proteins in the tumor microenvironment crucial in cancer invasion. Therefore, targeting eHsp90 could inhibit invasion, preventing metastasis—the leading cause of cancer-related mortality. Previous eHsp90 studies have solely focused on its role in cancer invasion through the 2D basement membrane (BM), a form of extracellular matrix (ECM) that lines the epithelial compartment. However, its role in cancer invasion through the 3D Interstitial Matrix (IM), an ECM beyond the BM, remains unexplored. Using a Collagen-1 binding assay and second harmonic generation (SHG) imaging, we demonstrate that eHsp90 directly binds and aligns Collagen-1 fibers, the primary component of IM. Furthermore, we show that eHsp90 enhances Collagen-1 invasion of breast cancer cells in the Transwell assay. Using Hsp90 conformation mutants and inhibitors, we established that the Hsp90 dimer binds to Collagen-1 via its N-domain. We also demonstrated that while Collagen-1 binding and alignment are not influenced by Hsp90's ATPase activity attributed to the N-domain, its open conformation is crucial for increasing Collagen-1 alignment and promoting breast cancer cell invasion. These findings unveil a novel role for eHsp90 in invasion through the IM and offer valuable mechanistic insights into potential therapeutic approaches for inhibiting Hsp90 to suppress invasion and metastasis. [ABSTRACT FROM AUTHOR]

Through a unique genomics and drug screening platform with ~800 solid tumor cell lines, we have found a subset of SCLC cell lines are hypersensitive to venetoclax, an FDA-approved inhibitor of BCL-2. SCLC-A (ASCL1 positive) and SCLC-P (POU2F3 positive), which make up almost 80% of SCLC, frequently express high levels of BCL-2. We found that a subset of SCLC-A and SCLC-P showed high BCL-2 expression but were venetoclax-resistant. In addition, most of these SCLC cell lines have TP53 missense mutations, which make a single amino acid change. These mutants not only lose wild-type (WT) p53 tumor suppressor functions, but also acquire novel cancer-promoting activities (oncogenic, gain-of-function). A recent study with oncogenic mutant (Onc)-p53 knock-in mouse models of SCLC suggests gain-of-function activity can attenuate chemotherapeutic efficacy. Based on these observations, we hypothesize that Onc-p53 confers venetoclax resistance and that simultaneous inhibition of BCL-2 and Onc-p53 induces synergistic anticancer activity in a subset of SCLC-A and SCLC-P. We show here that (1) down-regulation of Onc-p53 increases the expression of a BH3-only pro-apoptotic BIM and sensitizes to venetoclax in SCLC-P cells; (2) targeting Onc-p53 by the HSP90 inhibitor, ganetespib, increases BIM expression and sensitizes to venetoclax in SCLC-P and SCLC-A cells. Although there are currently many combination studies for venetoclax proposed, the concept of simultaneous targeting of BCL-2 and Onc-p53 by the combination of venetoclax and HSP90 inhibitors would be a promising approach for SCLC treatment. [ABSTRACT FROM AUTHOR]

Heat-shock proteins are upregulated in cancer and protect several client proteins from degradation. Therefore, they contribute to tumorigenesis and cancer metastasis by reducing apoptosis and enhancing cell survival and proliferation. These client proteins include the estrogen receptor (ER), epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), human epidermal growth factor receptor 2 (HER-2), and cytokine receptors. The diminution of the degradation of these client proteins activates different signaling pathways, such as the PI3K/Akt/NF-κB, Raf/MEK/ERK, and JAK/STAT3 pathways. These pathways contribute to hallmarks of cancer, such as self-sufficiency in growth signaling, an insensitivity to anti-growth signals, the evasion of apoptosis, persistent angiogenesis, tissue invasion and metastasis, and an unbounded capacity for replication. However, the inhibition of HSP90 activity by ganetespib is believed to be a promising strategy in the treatment of cancer because of its low adverse effects compared to other HSP90 inhibitors. Ganetespib is a potential cancer therapy that has shown promise in preclinical tests against various cancers, including lung cancer, prostate cancer, and leukemia. It has also shown strong activity toward breast cancer, non-small cell lung cancer, gastric cancer, and acute myeloid leukemia. Ganetespib has been found to cause apoptosis and growth arrest in these cancer cells, and it is being tested in phase II clinical trials as a first-line therapy for metastatic breast cancer. In this review, we will highlight the mechanism of action of ganetespib and its role in treating cancer based on recent studies. [ABSTRACT FROM AUTHOR]

Sorafenib, a multikinase inhibitor, is a first-line treatment for advanced hepatocellular carcinoma, but its long-term effectiveness is limited by the emergence of resistance mechanisms. One such mechanism is the reduction of microvessel density and intratumoral hypoxia caused by prolonged sorafenib treatment. Our research has demonstrated that HSP90 plays a critical role in conferring resistance to sorafenib in HepG2 cells under hypoxic conditions and N-Nitrosodiethylamine-exposed mice as well. This occurs through the inhibition of necroptosis on the one hand and the stabilization of HIF-1α on the other hand. To augment the effects of sorafenib, we investigated the use of ganetespib, an HSP90 inhibitor. We found that ganetespib activated necroptosis and destabilized HIF-1α under hypoxia, thus enhancing the effectiveness of sorafenib. Additionally, we discovered that LAMP2 aids in the degradation of MLKL, which is the mediator of necroptosis, through the chaperone-mediated autophagy pathway. Interestingly, we observed a significant negative correlation between LAMP2 and MLKL. These effects resulted in a reduction in the number of surface nodules and liver index, indicating a regression in tumor production rates in mice with HCC. Furthermore, AFP levels decreased. Combining ganetespib with sorafenib showed a synergistic cytotoxic effect and resulted in the accumulation of p62 and inhibition of macroautophagy. These findings suggest that the combined therapy of ganetespib and sorafenib may offer a promising approach for the treatment of hepatocellular carcinoma by activating necroptosis, inhibiting macroautophagy, and exhibiting a potential antiangiogenic effect. Overall, continued research is critical to establish the full therapeutic potential of this combination therapy.

Among the various types of cancer, lung cancer accounts for the highest number of fatalities across the globe. A combination of different cancer chemotherapeutics is regarded as an effective strategy for clinical management of different cancers. Ganetespib (GAN) is a well-established hsp90 inhibitor with enhanced pharmacological properties in comparison with its first-generation counterparts. Previous preclinical studies have shown that GAN exerts significant effects against cancer cells; however, its therapeutic effects against non-small cell lung cancer (NSCLC) A549 cells, achieved by modulating the expression of the NF-κB/p65 signaling pathway, remains unexplored. In this study, the combinatorial effect of GAN and methotrexate (MTX) against lung carcinomas was investigated through both in silico and in vitro studies. A combinatorial treatment regimen of GAN/MTX exerted more significant cytotoxic effects (p < 0.001) against A549 cells than individual treatments. The GAN/MTX combination also instigated nuclear fragmentation followed by augmentation in intracellular ROS levels (p < 0.001). The elevated ROS in A549 cells upon exposure to GAN/MTX combinatorial regimen was concomitantly accompanied with a remarkable reduction in mitochondrial viability. In addition, it was observed that the GAN/MTX combination succeeded in elevating caspase-3 activity and downregulating the expression levels of anti-apoptotic mediators Bcl2 and survivin in NSCLC A549 cells. Most importantly, the GAN/MTX combinatorial regimen impeded the activation of the NF-kB/p65 signaling pathway via repression of the expression of E-cadherin and N-cadherin, which was confirmed by molecular docking studies. Collectively, these findings demonstrated the synergistic effect of the GAN/MTX combinatorial regimen in suppressing the growth of A549 cells by modulating the NF-κB/p65 signaling pathway. [ABSTRACT FROM AUTHOR]

Abstract Objective Hypersensitivity towards proton versus photon irradiation was demonstrated in homologous recombination repair (HRR)-deficient cell lines. Hence, combined treatment concepts targeting HRR provide a rational for potential pharmaceutical exploitation. The HSP90 inhibitor ganetespib (STA-9090) downregulates a multitude of HRR-associated proteins and sensitizes for certain chemotherapeutics. Thus, the radiosensitizing effect of HSP90-inhibiting ganetespib was investigated for reference photon irradiation and proton irradiation at a proximal and distal position in a spread-out Bragg peak (SOBP). Methods A549 and FaDu cells were treated with low-dose (2 nM resp. 1 nM) ganetespib and irradiated with 200 kV photons. Proton irradiation was performed at a proximal and a distal position within a SOBP, with corresponding dose-averaged linear-energy transfer (LETD) values of 2.1 and 4.5 keV/µm, respectively. Cellular survival data was fitted to the linear-quadratic model to calculate relative biological effectiveness (RBE) and the dose-modifying factor (DMF). Additionally, A549 cells were treated with increasing doses of ganetespib and investigated by flow cytometry, immunoblotting, and immunofluorescence microscopy to investigate cell cycle distribution, Rad51 protein levels, and γH2AX foci, respectively. Results Low-dosed ganetespib significantly sensitized both cancer cell lines exclusively for proton irradiation at both investigated LETD, resulting in increased RBE values of 10–40%. In comparison to photon irradiation, the fraction of cells in S/G2/M phase was elevated in response to proton irradiation with 10 nM ganetespib consistently reducing this population. No changes in cell cycle distribution were detected in unirradiated cells by ganetespib alone. Protein levels of Rad51 are downregulated in irradiated A549 cells by 10 nM and also 2 nM ganetespib within 24 h. Immunofluorescence staining demonstrated similar induction and removal of γH2AX foci, irrespective of irradiation type or ganetespib administration. Conclusion Our findings illustrate a proton-specific sensitizing effect of low-dosed ganetespib in both employed cell lines and at both investigated SOBP positions. We provide additional experimental data on cellular response and a rational for future combinatorial approaches with proton radiotherapy.

Simple Summary: Hyperthermia boosts the effects of radio- and chemotherapy regimens, but its clinical potential is hindered by the ability of (cancer) cells to activate a protective mechanism known as the heat stress response. Strategies that inhibit its activation or functions have the potential, therefore, to improve the overall efficacy of hyperthermia-based treatments. In this study, we evaluated the efficacy of the HSP90 inhibitor ganetespib in promoting the effects of radiotherapy or cisplatin combined with hyperthermia in vitro and in a cervix cancer mouse model. Hyperthermia is being used as a radio- and chemotherapy sensitizer for a growing range of tumor subtypes in the clinic. Its potential is limited, however, by the ability of cancer cells to activate a protective mechanism known as the heat stress response (HSR). The HSR is marked by the rapid overexpression of molecular chaperones, and recent advances in drug development make their inhibition an attractive option to improve the efficacy of hyperthermia-based therapies. Our previous in vitro work showed that a single, short co-treatment with a HSR (HSP90) inhibitor ganetespib prolongs and potentiates the effects of hyperthermia on DNA repair, enhances hyperthermic sensitization to radio- and chemotherapeutic agents, and reduces thermotolerance. In the current study, we first validated these results using an extended panel of cell lines and more robust methodology. Next, we examined the effects of hyperthermia and ganetespib on global proteome changes. Finally, we evaluated the potential of ganetespib to boost the efficacy of thermo-chemotherapy and thermo-radiotherapy in a xenograft murine model of cervix cancer. Our results revealed new insights into the effects of HSR inhibition on cellular responses to heat and show that ganetespib could be employed to increase the efficacy of hyperthermia when combined with radiation. [ABSTRACT FROM AUTHOR]

Salivary gland tumors represent a serious medical problem and new tools for differential diagnosis and patient monitoring are needed. Here, we present data and discuss the potential of molecular chaperones as biomarkers and therapeutic targets, focusing on Hsp10 and Hsp90. The salivary glands are key physiological elements but, unfortunately, the information and the means available for the management of their pathologies, including cancer, are scarce. Progress in the study of carcinogenesis has occurred on various fronts lately, one of which has been the identification of the chaperone system (CS) as a physiological system with presence in all cells and tissues (including the salivary glands) that plays a role in tumor-cell biology. The chief components of the CS are the molecular chaperones, some of which belong to families of evolutionarily related molecules named heat shock protein (Hsp). We are quantifying and mapping these molecular chaperones in salivary glands to determine their possible role in the carcinogenetic mechanisms in these glands and to assess their potential as diagnostic biomarkers and therapeutic targets. Here, we report recent findings on Hsp10 and Hsp90 and show that the quantitative and topographic patterns of tissue Hsp90 are distinctive of malignant tumors and differentiate benign from malignant lesions. The Hsp90 results show a correlation between quantity of chaperone and tumor progression, which in turn calls for negative chaperonotherapy, namely, elimination/inhibition of the chaperone to stop the tumor. We found that in vitro, the Hsp90 inhibitor Ganetespib is cytotoxic for the salivary gland UM-HACC-2A cell line. The drug, by interfering with the pro-survival NF-κB pathway, hampers cellular proliferation and migration, and favors apoptosis, and can, therefore, be considered a suitable candidate for future experimentation to develop a treatment for salivary gland tumors. [ABSTRACT FROM AUTHOR]

Mantle cell lymphoma (MCL) is a highly aggressive and heterogeneous B-cell lymphoma. Though Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has shown great efficacy as a single agent for MCL treatment, the real-world use of ibrutinib is still subject to limitations. Our previous study has shown the treatment with HSP90 inhibitor ganetespib can attack major targets of MCL, luckily complementary to ibrutinib's targets. In this study, transient ganetespib treatment sensitizes MCL cells to ibrutinib as manifested by the significant decrease of IC50 values, percentages of EdU (5-Ethynyl-2′-deoxyuridine) positive cells, and levels of p-AKT and NF-κB after combinational treatment. Additionally, pretreatment with ganetespib enhanced cell cycle arrest induced by ibrutinib at G0/G1 phase and significantly decreased levels of cell cycle promoting proteins CDK2, 4, and 6. Pretreatment with ganetespib also enhanced cell apoptosis induced by ibrutinib through the upregulation of cleaved-caspase 9 and downregulation of BCL-2 in MCL cells at the molecular level. The sequential administration of ganetespib and ibrutinib had similar effects on increasing DNA damage as the transient treatment with ganetespib as demonstrated by the improved percentage of γH2AX and 53BP1 foci. Furthermore, ganetespib significantly increased inhibition of tumor growth mediated by ibrutinib in vivo, confirmed by the changes of the expression levels of Ki-67 and BCL-2 through immunohistochemistry assays. This study indicates that HSP90 inhibitor ganetespib maybe ideal for the combinational use with BTK inhibitor ibrutinib to target major pathogenesis-associated signaling pathways for MCL treatment which may help identify new possibilities for clinical trials. [ABSTRACT FROM AUTHOR]

Mantle cell lymphoma (MCL) is a highly aggressive and heterogeneous B-cell lymphoma. Though Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib has shown great efficacy as a single agent for MCL treatment, the real-world use of ibrutinib is still subject to limitations. Our previous study has shown the treatment with HSP90 inhibitor ganetespib can attack major targets of MCL, luckily complementary to ibrutinib’s targets. In this study, transient ganetespib treatment sensitizes MCL cells to ibrutinib as manifested by the significant decrease of IC50 values, percentages of EdU (5-Ethynyl-2′-deoxyuridine) positive cells, and levels of p-AKT and NF-κB after combinational treatment. Additionally, pretreatment with ganetespib enhanced cell cycle arrest induced by ibrutinib at G0/G1 phase and significantly decreased levels of cell cycle promoting proteins CDK2, 4, and 6. Pretreatment with ganetespib also enhanced cell apoptosis induced by ibrutinib through the upregulation of cleaved-caspase 9 and downregulation of BCL-2 in MCL cells at the molecular level. The sequential administration of ganetespib and ibrutinib had similar effects on increasing DNA damage as the transient treatment with ganetespib as demonstrated by the improved percentage of γH2AX and 53BP1 foci. Furthermore, ganetespib significantly increased inhibition of tumor growth mediated by ibrutinib in vivo, confirmed by the changes of the expression levels of Ki-67 and BCL-2 through immunohistochemistry assays. This study indicates that HSP90 inhibitor ganetespib maybe ideal for the combinational use with BTK inhibitor ibrutinib to target major pathogenesis-associated signaling pathways for MCL treatment which may help identify new possibilities for clinical trials.

Heat-shock proteins are upregulated in cancer and protect several client proteins from degradation. Therefore, they contribute to tumorigenesis and cancer metastasis by reducing apoptosis and enhancing cell survival and proliferation. These client proteins include the estrogen receptor (ER), epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), human epidermal growth factor receptor 2 (HER-2), and cytokine receptors. The diminution of the degradation of these client proteins activates different signaling pathways, such as the PI3K/Akt/NF-κB, Raf/MEK/ERK, and JAK/STAT3 pathways. These pathways contribute to hallmarks of cancer, such as self-sufficiency in growth signaling, an insensitivity to anti-growth signals, the evasion of apoptosis, persistent angiogenesis, tissue invasion and metastasis, and an unbounded capacity for replication. However, the inhibition of HSP90 activity by ganetespib is believed to be a promising strategy in the treatment of cancer because of its low adverse effects compared to other HSP90 inhibitors. Ganetespib is a potential cancer therapy that has shown promise in preclinical tests against various cancers, including lung cancer, prostate cancer, and leukemia. It has also shown strong activity toward breast cancer, non-small cell lung cancer, gastric cancer, and acute myeloid leukemia. Ganetespib has been found to cause apoptosis and growth arrest in these cancer cells, and it is being tested in phase II clinical trials as a first-line therapy for metastatic breast cancer. In this review, we will highlight the mechanism of action of ganetespib and its role in treating cancer based on recent studies.

Objective: Hypersensitivity towards proton versus photon irradiation was demonstrated in homologous recombination repair (HRR)-deficient cell lines. Hence, combined treatment concepts targeting HRR provide a rational for potential pharmaceutical exploitation. The HSP90 inhibitor ganetespib (STA-9090) downregulates a multitude of HRR-associated proteins and sensitizes for certain chemotherapeutics. Thus, the radiosensitizing effect of HSP90-inhibiting ganetespib was investigated for reference photon irradiation and proton irradiation at a proximal and distal position in a spread-out Bragg peak (SOBP).Methods: A549 and FaDu cells were treated with low-dose (2 nM resp. 1 nM) ganetespib and irradiated with 200 kV photons. Proton irradiation was performed at a proximal and a distal position within a SOBP, with corresponding dose-averaged linear-energy transfer (LETD) values of 2.1 and 4.5 keV/µm, respectively. Cellular survival data was fitted to the linear-quadratic model to calculate relative biological effectiveness (RBE) and the dose-modifying factor (DMF). Additionally, A549 cells were treated with increasing doses of ganetespib and investigated by flow cytometry, immunoblotting, and immunofluorescence microscopy to investigate cell cycle distribution, Rad51 protein levels, and γH2AX foci, respectively.Results: Low-dosed ganetespib significantly sensitized both cancer cell lines exclusively for proton irradiation at both investigated LETD, resulting in increased RBE values of 10-40%. In comparison to photon irradiation, the fraction of cells in S/G2/M phase was elevated in response to proton irradiation with 10 nM ganetespib consistently reducing this population. No changes in cell cycle distribution were detected in unirradiated cells by ganetespib alone. Protein levels of Rad51 are downregulated in irradiated A549 cells by 10 nM and also 2 nM ganetespib within 24 h. Immunofluorescence staining demonstrated similar induction and removal of γH2AX foci, irrespective of irradiation type or ganetespib administration.Conclusion: Our findings illustrate a proton-specific sensitizing effect of low-dosed ganetespib in both employed cell lines and at both investigated SOBP positions. We provide additional experimental data on cellular response and a rational for future combinatorial approaches with proton radiotherapy. [ABSTRACT FROM AUTHOR]

Immunotherapy is blooming in recent years. However, this therapy needs to overcome off-target effects, cytokine release syndrome, and low responses in the 'cold' tumor environment. Herein, various combinations of immunotherapies and chemotherapies were proposed to transform 'cold' tumors into 'hot' tumors to enhance the efficacy of immunotherapies. In this study, we prepared a biocompatible ganetespib (GSP)-loaded PEGylated nanocarriers (NCs) with a thin-film method, which exhibited a small particle size (~220.6 nm), high drug loading (~5.8%), and good stability. We designed and produced the cluster of differentiation 3 (CD3)/programmed death ligand 1 (PD-L1)/methoxy-polyethylene glycol (mPEG) trispecific antibodies (TsAbs) as bispecific T-cell engagers (BiTEs) to non-covalently bind the GSP-NCs via anti-mPEG fragment and endowed the GSP-NCs with a targeting ability and immunotherapeutic potential to activate cytotoxic T cells. Decoration of the GSP-NCs with TsAbs (BiTEs-GSP-NCs) significantly promoted the cellular uptake and showed synergistic effects through respective anti-PD-L1 and anti-CD3 activation of T cell-mediated cytotoxicity. In vivo tumor-inhibition studies also showed that the BiTEs-GSP-NCs could inhibit tumor growth with the GSP chemodrug and increase T-cell infiltration. This study provides a promising drug delivery strategy for cancer immunochemotherapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Among the various types of cancer, lung cancer accounts for the highest number of fatalities across the globe. A combination of different cancer chemotherapeutics is regarded as an effective strategy for clinical management of different cancers. Ganetespib (GAN) is a well-established hsp90 inhibitor with enhanced pharmacological properties in comparison with its first-generation counterparts. Previous preclinical studies have shown that GAN exerts significant effects against cancer cells; however, its therapeutic effects against non-small cell lung cancer (NSCLC) A549 cells, achieved by modulating the expression of the NF-κB/p65 signaling pathway, remains unexplored. In this study, the combinatorial effect of GAN and methotrexate (MTX) against lung carcinomas was investigated through both in silico and in vitro studies. A combinatorial treatment regimen of GAN/MTX exerted more significant cytotoxic effects (p < 0.001) against A549 cells than individual treatments. The GAN/MTX combination also instigated nuclear fragmentation followed by augmentation in intracellular ROS levels (p < 0.001). The elevated ROS in A549 cells upon exposure to GAN/MTX combinatorial regimen was concomitantly accompanied with a remarkable reduction in mitochondrial viability. In addition, it was observed that the GAN/MTX combination succeeded in elevating caspase-3 activity and downregulating the expression levels of anti-apoptotic mediators Bcl2 and survivin in NSCLC A549 cells. Most importantly, the GAN/MTX combinatorial regimen impeded the activation of the NF-kB/p65 signaling pathway via repression of the expression of E-cadherin and N-cadherin, which was confirmed by molecular docking studies. Collectively, these findings demonstrated the synergistic effect of the GAN/MTX combinatorial regimen in suppressing the growth of A549 cells by modulating the NF-κB/p65 signaling pathway.

Salivary gland tumors represent a serious medical problem and new tools for differential diagnosis and patient monitoring are needed. Here, we present data and discuss the potential of molecular chaperones as biomarkers and therapeutic targets, focusing on Hsp10 and Hsp90. The salivary glands are key physiological elements but, unfortunately, the information and the means available for the management of their pathologies, including cancer, are scarce. Progress in the study of carcinogenesis has occurred on various fronts lately, one of which has been the identification of the chaperone system (CS) as a physiological system with presence in all cells and tissues (including the salivary glands) that plays a role in tumor-cell biology. The chief components of the CS are the molecular chaperones, some of which belong to families of evolutionarily related molecules named heat shock protein (Hsp). We are quantifying and mapping these molecular chaperones in salivary glands to determine their possible role in the carcinogenetic mechanisms in these glands and to assess their potential as diagnostic biomarkers and therapeutic targets. Here, we report recent findings on Hsp10 and Hsp90 and show that the quantitative and topographic patterns of tissue Hsp90 are distinctive of malignant tumors and differentiate benign from malignant lesions. The Hsp90 results show a correlation between quantity of chaperone and tumor progression, which in turn calls for negative chaperonotherapy, namely, elimination/inhibition of the chaperone to stop the tumor. We found that in vitro, the Hsp90 inhibitor Ganetespib is cytotoxic for the salivary gland UM-HACC-2A cell line. The drug, by interfering with the pro-survival NF-κB pathway, hampers cellular proliferation and migration, and favors apoptosis, and can, therefore, be considered a suitable candidate for future experimentation to develop a treatment for salivary gland tumors.

Sorafenib, a multikinase inhibitor, is a first-line treatment for advanced hepatocellular carcinoma, but its long-term effectiveness is limited by the emergence of resistance mechanisms. One such mechanism is the reduction of microvessel density and intratumoral hypoxia caused by prolonged sorafenib treatment. Our research has demonstrated that HSP90 plays a critical role in conferring resistance to sorafenib in HepG2 cells under hypoxic conditions and N-Nitrosodiethylamine-exposed mice as well. This occurs through the inhibition of necroptosis on the one hand and the stabilization of HIF-1α on the other hand. To augment the effects of sorafenib, we investigated the use of ganetespib, an HSP90 inhibitor. We found that ganetespib activated necroptosis and destabilized HIF-1α under hypoxia, thus enhancing the effectiveness of sorafenib. Additionally, we discovered that LAMP2 aids in the degradation of MLKL, which is the mediator of necroptosis, through the chaperone-mediated autophagy pathway. Interestingly, we observed a significant negative correlation between LAMP2 and MLKL. These effects resulted in a reduction in the number of surface nodules and liver index, indicating a regression in tumor production rates in mice with HCC. Furthermore, AFP levels decreased. Combining ganetespib with sorafenib showed a synergistic cytotoxic effect and resulted in the accumulation of p62 and inhibition of macroautophagy. These findings suggest that the combined therapy of ganetespib and sorafenib may offer a promising approach for the treatment of hepatocellular carcinoma by activating necroptosis, inhibiting macroautophagy, and exhibiting a potential antiangiogenic effect. Overall, continued research is critical to establish the full therapeutic potential of this combination therapy. • Necroptosis is attenuated in HCC cells under hypoxia. • HSP90 conferred resistance of HCC cells to sorafenib treatment under hypoxia. • In HCC, ganetespib/sorafenib decreased LAMP2 and inhibited MLKL degradation. • Ganetespib augmented sorafenib efficacy by inducing necroptosis in HCC cells. • In HCC, ganetespib/sorafenib suppressed CMA and macroautophagy. [ABSTRACT FROM AUTHOR]

Osteosarcoma is common childhood tumour type of the bone. Chemotherapy is the most important step in treatment of osteosarcoma. Despite advanced diagnosis methods and target specific cancer therapeutics, osteosarcoma has still a high mortality rate and a tendency to metastasize. Therefore, new therapeutic strategies are evaluated in osteosarcoma treatment in pre-clinical and clinical studies. In the last ten years, heat shock protein 90 (HSP90) has been important biological target to design target specific cancer drugs. HSP90 play vital roles in proper folding, stabilization and maintenance of oncogenic client proteins in tumorigenesis. Therefore, inhibition of HSP90 has been significant therapeutic aspects in cancer drug design. STA-9090 (ganetespib) is a second generation small molecule HSP90 inhibitor which blocks tumurogenesis in cancer cells. STA-9090 inhibited ATP hydrolysis and protein folding process of HSP90. In this study, STA-9090 decreased Saos-2 cell proliferation and IC 50 dose of STA-9090 was found out as 18.71 µM and 10.25 µM at 24 h and 48 h, respectively. STA-9090 inhibited HSP90 ATPase function and disrupted oncogenic client protein folding activity. Also, STA-9090 decreased protein level of the HSP90 in osteosarcoma cells. Expression analysis of osteosarcoma and bone metabolism related genes was performed by RT 2 Profiler PCR Array. This study has found the down-regulation of the expression levels of oncogenic genes: DKK1 , TWIST1 , WNT10B , WNT3A , RANK , RANKL , PTH , FGFR1 , FGFR2 , LTBP2 , IL6 , TGFβ1 , MMP2 and SPARC genes, in STA-9090 treated Saso-2 cells. Furthermore, expression levels of osteosarcoma related genes, OPG , ERα , ERβ , IL15 , BMP2 and BMP7 , were found to have increased significantly. Biological activities of STA-9090 on Saos-2 cell line show its potential as a target specific drug to inhibit osteosarcoma and its metastasis.