Combining HSP70 and HSF1 inhibitors may be a promising anti-cancer strategy, offering a potential solution to overcome the negative feedback mechanism and enhance anti-cancer effects.

Inhibition of Hsp70 upregulation by mEHT was also supported by qPCR and IHC. In conclusion, we suggest that mEHT-therapy combined with HSF1 inhibition can be a possible new strategy of TNBC treatment with great translational potential.

P1, N=7, Terminated, Roswell Park Cancer Institute | N=36 --> 7 | Trial completion date: Aug 2024 --> Jan 2024 | Recruiting --> Terminated | Trial primary completion date: Aug 2024 --> Jan 2024; low accrual

Furthermore, the combination treatment inhibits tumor growth and AKT signaling in the xenograft mouse model, increases levels of the tumor tissue oxidation product malondialdehyde (MDA), and induces DNA damage. To summarize, a potential therapeutic approach for NSCLC may involve dual inhibition of AURK and HSF1, resulting in the downregulation of the PI3K/AKT signaling pathway, and the activation of ROS-mediated mitochondrial and DNA damage pathways.

With its important roles in tumorigenesis and tumor progression, targeting HSF1 offers a novel cancer treatment strategy. In this article, we examine the basic function of HSF1 and its regulatory mechanisms, focus on the mechanisms involved in HSF1's roles in different cancer types, and examine current HSF1 inhibitors as novel therapeutics to treat cancers.

HSF1 suppressed expression of CCL5, a chemokine for CD8+ T cells, and upregulation of CCL5 upon HSF1 loss significantly contributed to the recruitment of CD8+ T cells. These findings indicate that HSF1 suppresses antitumor immune activity by reducing CCL5 to limit CD8+ T cell homing to breast tumors and prevent immune-mediated destruction, which has implications for the lack of success of immune modulatory therapies in breast cancer.

No abstract available

Immunohistochemistry confirmed the molecular data. Combined therapy of mEHT and KRIBB11 significantly reduced tumor weight (160.3 mg ± 33.26 mg) further compared to monotherapy (mEHT: 236.8 mg ± 46.42 mg; KRIBB11: 312.3 mg ± 41.45 mg).ConclusionCombined mEHT-therapy with HSF1 inhibition can be a possible new strategy of treating TNBC with a great translational potential.

Further multiparameter optimization led to the design of the clinical candidate, CCT361814/NXP800 22, a potent and orally bioavailable fluorobisamide, which caused tumor regression in a human ovarian adenocarcinoma xenograft model with on-pathway biomarker modulation and a clean in vitro safety profile. Following its favorable dose prediction to human, 22 has now progressed to phase 1 clinical trial as a potential future treatment for refractory ovarian cancer and other malignancies.

P1, N=61, Recruiting, Nuvectis Pharma, Inc. | N=17 --> 61 | Trial completion date: Apr 2023 --> Jun 2025 | Trial primary completion date: Jan 2023 --> Dec 2024

Using an siRNA approach to determine if activation of the ISR components was contributing to growth inhibition following NXP800 exposure, we found that blocking the induction of ATF4 reduced the response of NXP800-sensitive SK-OV-3 human ovarian carcinoma cells to NXP800 treatment.In summary, NXP800 acts on cancer cells to induce activation of the ISR pathway via GCN2, which then leads to inhibition of HSF1 activation. Further studies are underway to determine the precise molecular target of NXP800 and the mechanism of HSF1 pathway inhibition.

NXP800, a HSF1 inhibitor, demonstrated significant therapeutic activity in a cholangiocarcinoma PDX. Further studies are needed and being performed to determine the role of HSF1 inhibition in human cholangiocarcinoma.

Furthermore, targeting the DYRK2-HSF1 axis induces death in proteasome inhibitor resistant cells and reduces triple-negative breast cancer burden in ectopic and orthotopic xenograft models. Together the data indicate that co-targeting of kinase DYRK2 and its substrate HSF1 could prove to be a beneficial strategy in perturbing neoplastic malignancies.

Planned phase 1b expansion cohorts will include ovarian clear cell carcinoma and ovarian endometrioid carcinoma patients with ARID1A mutation. Legal entity responsible for the study The authors.

Importantly, the growth and engraftment of human AML cells are suppressed by HSF1 inhibition. Our data provide a rationale for developing efficacious small molecules to specifically target HSF1 in AML.

Conclusions A Phase 1 trial (NCT05226507) of NXP800 is underway, incorporating the validated predictive, PK and PD biomarkers that constitute a Pharmacological Audit Trail. Future expansion cohorts will include patients with ARID1A mutation, including ovarian clear cell carcinoma and ovarian endometrioid carcinoma.

P1/2, N=38, Active, not recruiting, Children's Oncology Group | Recruiting --> Active, not recruiting

Our study reveals a novel mechanism in which HSF1 promotes the chemoresistance of pancreatic cancer to gemcitabine by modulating CSC-like properties. Targeting HSF1 could be thus a rational strategy to improve treatment outcomes.

P1/2, N=38, Recruiting, Children's Oncology Group | Not yet recruiting --> Recruiting | Trial primary completion date: Feb 2026 --> Dec 2026

HSF1 can interact with GLS1 and elevate the expression of GLS1. GLS1 can partially abolish the suppressive effect of miR-455-3p in NSCLC cells.miR-455-3p can bind HSF1 to suppress the GLS1 in NSCLC cells, therefore suppressing EMT progression and angiogenesis of NSCLC cells.

P1/2, N=38, Not yet recruiting, Children's Oncology Group | Trial primary completion date: Dec 2026 --> Feb 2026

FTO inhibition, especially when combined with bortezomib treatment, synergistically inhibited myeloma bone tumor formation and extramedullary spread in NOD-Prkdcil2rg/Nju (NCG) mice. We demonstrated the functional importance of mA demethylase FTO in MM progression, especially in promoting extramedullary myeloma formation and proposed the FTO-HSF1/HSP axis as a potential novel therapeutic target in MM.

High expression of PLOD1 can increase the proliferation and colony formation of U87 cells by activating the HSF1 signaling pathway. This study suggested PLOD1/HSF1 as an effective therapeutic target for gliomas.

We suggest an involvement of HSP70/HSF1 axis in controlling resistance to ibrutinib in CLL cells, since their inhibition is effective in inducing in vitro apoptosis in cells from ibrutinib refractory patients. The targeting of HSP70/HSF1 axis could represent a novel rational therapeutic strategy for CLL, also for relapsing patients.

NCT-58 treatment suppressed growth and angiogenesis in a trastuzumab-resistant xenograft model, concomitant with downregulation of ICD-HER2 and HSF-1/HSP70/HSP90. These findings warrant further investigation of NCT-58 to address trastuzumab resistance in heterogeneous HER2-positive cancers.

P1/2, N=38, Not yet recruiting, Children's Oncology Group | Initiation date: Sep 2021 --> Dec 2021

In conclusion, stabilization of MULE upon KRIBB11 treatment is apparently an essential step for degradation of MCL-1 and the subsequent induction of apoptosis in A172 cells. Our results have expanded the knowledge on molecular pathways controlled by KRIBB11 and could be potentially effective for developing an inhibitory therapeutic strategy for glioblastoma.

Pifithrin-μ (PFTμ, HSP70 inhibitor) decreased or removed the effects of peptide in increasing the sensitivity of ovarian cancer cells to DDP. This suggests that PGPIPN enhanced the sensitivity of ovarian cancer cells to DDP partially via reducing the activity of HSF1/HSP70 signaling pathway, thus inducing cell apoptosis and decreasing repairment of DNA damage.

Furthermore, EAS significantly increased progesterone synthesis. Thus, EAS improves HSP70-mediated redox balance and cell function in bovine CG cells.

VLX1570 increased the amount of high molecular weight polyubiquitinated proteins and the expression of HSP70 as the result of the suppression of ubiquitine proteasome system, the expression of heme oxygenase-1 and the amount of phosphorylation in JNK and p38 associated with the generation of reactive oxygen species (ROS) induced apoptosis and the amount of phosphorylation in eIF2α, inducing the expression of ATF4 and endoplasmic reticulum (ER) stress dependent apoptosis protein, CHOP and the amount of phosphorylation slightly in IRE1α, leading to increased expression of XBP-1s in leukemia cell lines. In the present study, we demonstrate that VLX1570 induces apoptosis and exerts a potential anti-leukemic effect through the generation of ROS and induction of ER stress in leukemia cell lines.

Functionally, an inhibition of LDH causes a generalized reduction of cytosolic and membrane-bound HSPs in tumor cells and significantly increases the radiosensitivity, which is associated with a G2/M arrest. We demonstrate that targeting of the lactate/pyruvate metabolism breaks the radioresistance by impairing the stress response.

Thus, Cinnamaldehyde induced apoptosis and decreased growth in 5637 cells by reducing ErbB2-HSF1-LDHA pathway.

Furthermore, PES suppressed EMT features, cell motility, and expression of specific transcription factors. In conclusion, the Hsp70 chaperone machine efficiently protects mechanisms of the EMT, and the safe inhibitors of the chaperone are needed to hamper metastasis at its initial stage.

In p53 tumors WTp53 activation by constitutive stress represses MLK3, thereby weakening the MAPK-HSF1 response necessary for tumor survival. This creates selection pressure for p53LOH which eliminates the repressive WTp53-MAPK-HSF1 axis and unleashes tumor-promoting HSF1 functions, inducing mutp53 stabilization enabling invasion.

The formation of HiNoCo body is reversible and independent of heat shock factor 1, the master transcription regulator of the heat-shock response. Our results suggest the HiNoCo body participates in heat shock factor 1-independent heat-shock responses in mammalian cells.

We generated erlotinib-resistant HCC827-ErlR cells, which showed resistance to erlotinib, gefitinib, osimertinib, and doxorubicin. Finally, we demonstrated the efficacy of the HSF1 inhibitor on PC9-ErlR cells expressing mutant EGFR (T790M) in vivo. Collectively, these findings support a targetable HSF1-(HSP90/HSP70/BAG3)-(BCL2/MCL1/EGFR/MET/AXL) pathway to overcome multiple mechanisms of EGFR-TKI resistance.

Combined inhibition of AURKA and HSF1 shows an excellent anti-tumor effect on HCC cells in vitro and in vivo, which may be mediated by ERS. These findings suggest that both AURKA and HSF1 may serve as targets for HCC treatment.

These results indicated that miR-135b-5p upregulation in colorectal cancer could induce protective autophagy through the MUL1/ULK1 signaling pathway and promote oxaliplatin resistance. Targeting miR-135b-5p may provide a new treatment strategy for reversing oxaliplatin resistance in CRC.

Consistently, the combination of RHT and FLT3 inhibitors was highly synergistic in primary FLT3-mutated AML cells. Our results provide a novel therapeutic rationale for co-targeting eIF4A and FLT3 to address the clinical challenge of treating FLT3-mutant AML.