HSP90 inhibition acts synergistically with heat to induce a pro-immunogenic form of cell death in colon cancer cells

Abstract

Background: Sub-ablative heat induces pleiotropic biological effects in cancer cells, activating programmed cell death or survival processes. These processes decide the fate of the heated cell. This study investigates these and assesses whether heat, in combination with HSP90 inhibition, augments cell death and induces a pro-immune phenotype in these cells. Methods: HCT116 and HT29 cells were subjected to thermal doses (TID) of 60 and 120CEM 43 using a PCR thermal cycler. HSP90 was inhibited with NVP-AUY922. Viability was assessed using the MTT assay. Cellular ATP and HSP70 release were assessed using ATP and Enzyme-linked Immunosorbent assays, respectively. Flow cytometry and immunoblotting were used to study the regulation of biomarkers associated with the heat shock response, the cell cycle, and immunogenic and programmed cell death. Results: Exposure of HCT116 and HT29 cells to TIDs of 60 and 120CEM 43 decreased their viability. In addition, treatment with 120CEM 43 increased intracellular HSP70 and the percentage of HCT116/HT29 cells in the G2/M cell cycle phase, ATP release and Calreticulin/HSP70/HSP90 exposure in the plasma membrane, while downregulating CD47 compared to sham-exposed cells. When combined with NVP-AUY922, treatment of HCT116/HT29 cells with 120CEM 43 resulted in a synergistic decrease of cell viability associated with the induction of apoptosis. Also, the combined treatments increased Calreticulin exposure, CD47 downregulation, and HSP70 release compared to the sham-exposed cells. Conclusion: Sub-ablative heating can act synergistically with the clinically relevant HSP90 inhibitor NVP-AUY922 to induce a pro-immunogenic form of cell death in colon cancer cells.

Focused Ultrasound as Targeted Therapy for Colorectal Cancer: A Comprehensive Review

“…Combined with HSP90 inhibition, thermal doses led to synergistic decreases in cell viability and the induction of apoptosis, along with increased Calreticulin exposure, CD47 downregulation, and HSP70 release. These findings suggest that sub-ablative heating, in combination with HSP90 inhibition, can promote a pro-immunogenic form of cell death in colon cancer cells [78]. Some research studies evaluated the immunological response triggered by HIFU treatment in mice with colon adenocarcinoma tumors.…”

Latest Advances in the Use of Therapeutic Focused Ultrasound in the Treatment of Pancreatic Cancer

“…When focused ultrasound is applied in its continuous "thermal" mode (exposures lasting seconds), the tissue is subjected to frictional forces which are converted to heat [74]. Hyperthermia treatments (characterised by temperatures of 43-45 • C maintained for up to an hour) have been used to sensitise tumours to the effects of radiotherapy and chemotherapy [75][76][77][78][79][80][81][82][83][84][85][86][87]. At higher power, high-intensity focused ultrasound (HIFU) heats cells rapidly, to temperatures over 56 • C for a few seconds, resulting in thermal necrosis and instantaneous cell death.…”

“…Cancers 2022, 14, x FOR PEER REVIEW 4 of 25 temperatures of 43-45 °C maintained for up to an hour) have been used to sensitise tumours to the effects of radiotherapy and chemotherapy [75][76][77][78][79][80][81][82][83][84][85][86][87]. At higher power, highintensity focused ultrasound (HIFU) heats cells rapidly, to temperatures over 56 °C for a few seconds, resulting in thermal necrosis and instantaneous cell death.…”

“…The development of ultrasound and magnetic resonance imaging (MRI)-guided clinical systems capable of thermally ablating tissue led to the extensive investigation of the immunogenic effects of "thermal" focused ultrasound in preclinical and clinical studies (Table 2). In vitro heating of colon, lung and ovarian cells with ablative and sub-ablative thermal iso-effective doses (TID) have been shown to result in the induction of immunogenic cell death (ICD) and the release of damage-associated molecular patterns (DAMPs), including calreticulin ATP and HSP70 release, HSP70 and HSP90 exposure on the plasma membrane and CD47 downregulation (parameters: T = 45-56 • C, TID = 60 to >> 240 CEM 43 ) [80,114]. In vivo, treatment of murine hepatocellular tumours with "thermal" ablative focused ultrasound using a 2-cm-diameter transducer has doubled the cytotoxic activity of T cells, increased the secretion of IFNγ and TNFα [115] and produced a statistically significant maturation of DC and subsequent activation of T cytotoxic cells against the tumours (parameters: f = 9.5 MHz, Power = 5 W, exposure time = 220 s) [111].…”

Enhancing Magnetic Hyperthermia Efficacy through Targeted Heat Shock Protein 90 Inhibition: Unveiling Immune-Mediated Therapeutic Synergy in Glioma Treatment

“…This, along with increased antigen expression, can help recruit more T-cells to attack the tumor cells, resulting in a stronger antitumor immune response . This response has been observed to not only eliminate the primary tumor but also distant untreated metastatic tumors, known as the abscopal effect . A study by Huang et al has reported that HSP90 inhibition acts synergistically with subablative heat induced by the PCR thermal cycler to induce a pro-immunogenic form of cell death by increased calreticulin exposure on the plasma membrane, downregulation of CD47, and release of HSP70 in colon cancer cells grown as monolayers post-96 h of treatment .…”