HSF1 Inhibits Antitumor Immune Activity in Breast Cancer by Suppressing CCL5 to Block CD8+ T-cell Recruitment

Overcoming immunotherapy resistance in colorectal cancer through nano-selenium probiotic complexes and IL-32 modulation

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is a major global health burden, with immunotherapy often limited by immune tolerance and resistance. This study introduces an innovative approach using Selenium Nanoparticles-Loaded Extracellular Vesicles combined with Interleukin-32 and Engineered Probiotic Escherichia coli Nissle 1917 (SeNVs@NE-IL32-EcN) to enhance CD8+ T cell-mediated immune responses and overcome immunotherapy resistance.

METHODS

Single-cell RNA sequencing (scRNA-seq) and transcriptomic analyses were performed to identify key immune cells and regulators involved in CRC immunotherapy resistance, focusing on CD8+ T cells and the regulatory factor IL32. A humanized xenograft mouse model was used to evaluate the impact of IL32 and SeNVs@NE-IL32-EcN on tumor growth and immune responses. The SeNVs@NE-IL32-EcN complex was synthesized through a reverse micelle method and functionalized using extracellular vesicles. Its morphology, size, antioxidant activity, and safety were characterized using electron microscopy, dynamic light scattering (DLS), and in vitro co-culture assays.

RESULTS

Single-cell analyses revealed a significant reduction in CD8+ T cell infiltration in immunotherapy-resistant CRC patients. IL32 was identified as a key regulator enhancing CD8+ T cell cytotoxic activity through granzyme B and IFN-γ secretion. Treatment with SeNVs@NE-IL32-EcN significantly improved the proliferation and activity of CD8+ T cells and reduced tumor progression in humanized mouse models. In vitro and in vivo results demonstrated the complex's biocompatibility, antioxidant properties, and ability to enhance CRC immunotherapy while mitigating immune tolerance.

CONCLUSION

SeNVs@NE-IL32-EcN offers a novel nano-biomaterial strategy that integrates nanotechnology and probiotic therapy to enhance CD8+ T cell-mediated immunity and overcome CRC immunotherapy resistance. This study lays the foundation for future therapeutic applications in cancer treatment by advancing immune-modulating biomaterials.

The combination of flaxseed lignans and PD-1/ PD-L1 inhibitor inhibits breast cancer growth via modulating gut microbiome and host immunity

BACKGROUND

Patients with breast cancer (BC) who benefit from the PD-1/PD-L1 inhibitor (PDi) is limited, necessitating novel strategies to improve immunotherapy efficacy of BC. Here we aimed to investigate the inhibitory effects of flaxseed lignans (FL) on the biological behaviors of BC and evaluate the roles of FL in enhancing the anticancer effects of PDi.

METHODS

HPLC was used to detect the content of enterolactone (ENL), the bacterial transformation product of FL. Transcript sequencing was performed and identified CD38 as a downstream target gene of ENL. CD38-overexpressing cells were constructed and cell proliferation, colony formation, wound healing and transwell assays were used to assess the function of ENL/CD38 axis on BC cells in vitro. Multiplexed immunohistochemistry (mIHC) and CyTOF were used to detect the changes of the tumor immune microenvironment (TIM). 16S rDNA sequencing was used to explore the changes of gut microbiota in mice. A series of in vivo experiments were conducted to investigate the anticancer effects and mechanisms of FL and PDi.

RESULTS

FL was converted to ENL by gut microbiota and FL administration inhibited the progression of BC. ENL inhibited the malignant behaviors of BC by downregulating CD38, a key gene associated with immunosuppression and PD-1/PD-L1 blockade resistance. The mIHC assay revealed that FL administration enhanced CD3+, CD4+ and CD8+ cells and reduced F4/80+ cells in TIM. CyTOF confirmed the regulatory effects of FL and FL in combination with PDi (FLcPDi) on TIM. In addition, 16S rDNA analysis demonstrated that FLcPDi treatment significantly elevated the abundance of Akkermansia and, importantly, Akkermansia administration enhanced the response to PDi in mice treated with antibiotics.

CONCLUSIONS

The FL/ENL/CD38 axis inhibited BC progression. FL enhanced the anticancer effects of PDi by modulating gut microbiota and host immunity.

Amyloidogenesis promotes HSF1 activity enhancing cell survival during breast cancer metastatic colonization

Breast cancer is the most commonly diagnosed cancer among women and the second leading cause of cancer deaths in women. A majority of these breast cancer deaths are due to metastasis, which occurs when primary tumor cells invade into the blood stream to travel and colonize at distant organ sites. Metastatic colonization is the rate-limiting step of metastasis. Heat shock factor 1 (HSF1) is a transcription factor that has been shown to be involved in promoting malignancy with a function in metastatic dissemination due to its contribution to promoting epithelial-to-mesenchymal transition. The role of HSF1 in colonization is unclear. In this study, we observed that HSF1 was essential for metastatic colonization. Consistent with these findings, we also observed that HSF1 was more active in human metastatic tumors compared to primary tumors. HSF1 was also seen to be activated during in vitro colony formation, which was accompanied by increases in amyloid beta (Aβ) fibrils, which was also observed in human metastatic tumors. Aβ fibrils led to HSF1 activation and depletion or inhibition of HSF1 led to increases in Aβ fibrils. HSF1 inhibition with small molecule inhibitors suppressed in vitro colony formation and mammosphere growth of metastatic breast cancer cells. These results suggest that colonization increases Aβ fibril formation that subsequently activates HSF1 as a cell survival mechanism that is essential for metastatic initiation and outgrowth.

Harnessing the power of traceable system C-GAP: homologous-targeting to fire up T-cell immune responses with low-dose irradiation

While radiotherapy-induced immunogenic cell death (ICD) holds potential for enhancing cancer immunotherapy, the conventional high-dose irradiation often leads to an immunosuppressive microenvironment and systemic toxicity. Therefore, a biomimetic nanoplatform cell membrane coated-nitrogen-doped graphene quantum dots combined with Au nanoparticles (C-GAP) was developed in this study. Firstly, homologous and traceable targeting features of C-GAP enables tumor-selective accumulation, providing reference for the selection of the timing of radiotherapy. Secondly, radiosensitization by C-GAP with Low-dose irradiation (LDI) amplifies reactive oxygen species (ROS) generation to trigger potent ICD. Thirdly, remarkable immune remodeling induced by C-GAP enhances CD8+ T cell infiltration and effector function. Single-cell RNA sequencing revealed that C-GAP-LDI combination upregulates TNF and CCL signaling pathway expression in tumor-infiltrating CD8+ T cells which potentiates tumor eradication. Our findings present a novel approach for safe and effective radioimmunotherapy, where C-GAP sensitized LDI achieves therapeutic enhancement through precise ICD induction and systemic immune activation.

MYC and HSF1 Cooperate to Drive Sensitivity to Polo-like Kinase 1 Inhibitor Volasertib in High-grade Serous Ovarian Cancer

SIGNIFICANCE

We show that HSF1 and MYC genes are co-amplified in more than 30% of HGSOC and demonstrate that HSF1 and MYC functionally cooperate to drive the growth of HGSOC cells. This work provides the foundation for HSF1 and MYC co-amplification as a biomarker for treatment efficacy of the polo-like kinase 1 inhibitor volasertib in HGSOC.

Single-Cell Multiomics Identifies Glycan Epitope LacNAc as a Potential Cell-Surface Effector Marker of Peripheral T Cells in Bladder Cancer Patients

Cancer is a systemic disease continuously monitored and responded to by the human global immune system. Peripheral blood immune cells, integral to this surveillance, exhibit variable phenotypes during tumor progression. Glycosylation, as one of the most prevalent and significant post-translational modifications of proteins, plays a crucial role in immune system recognition and response. Glycan analysis has become a key method for biomarker discovery. LacNAc, a prominent glycosylation modification, regulates immune cell activity and function. Therefore, we applied our previously developed single-cell glycomic multiomics to analyze peripheral blood in cancer patients. This platform utilizes chemoenzymatic labeling with DNA barcodes for detecting and quantifying LacNAc levels at single-cell resolution without altering the transcriptional status of immune cells. For the first time, we systematically integrated single-cell transcriptome, T cell receptor (TCR) repertoire, and glycan epitope LacNAc analyses in tumor-patient-derived peripheral blood. Our integrated analysis reveals that lower-stage bladder cancer patients showed significantly higher levels of LacNAc in peripheral T cells, and peripheral T cells with high levels of cell-surface LacNAc exhibit higher cytotoxicity and TCR clonal expansion. In summary, we identified LacNAc as a potential cell-surface effector marker for peripheral T cells in bladder cancer patients, which enhances our understanding of peripheral immune cells and offers potential advancements in liquid biopsy.

Unveiling the HSF1 Interaction Network: Key Regulators of Its Function in Cancer

Heat shock factor 1 (HSF1) plays a central role in orchestrating the heat shock response (HSR), leading to the activation of multiple heat shock proteins (HSPs) genes and approximately thousands of other genes involved in various cellular functions. In cancer cells, HSPs play a particular role in coping with the accumulation of damaged proteins resulting from dysregulated translation and post-translational processes. This proteotoxic stress is a hallmark of cancer cells and causes constitutive activation of HSR. Beyond its role in the HSR, HSF1 regulates diverse processes critical for tumor cells, including proliferation, cell death, and drug resistance. Emerging evidence also highlights HSF1's involvement in remodeling the tumor immune microenvironment as well as in the maintenance of cancer stem cells. Consequently, HSF1 has emerged as an attractive therapeutic target, prompting the development of specific HSF1 inhibitors that have progressed to clinical trials. Importantly, HSF1 possesses a broad interactome, forming protein-protein interactions (PPIs) with components of signaling pathways, transcription factors, and chromatin regulators. Many of these interactors modulate HSF1's activity and HSF1-dependent gene expression and are well-recognized targets for cancer therapy. This review summarizes the current knowledge on HSF1 interactions with molecular chaperones, protein kinases, and other regulatory proteins. Understanding the key HSF1 interactions promoting cancer progression, along with identifying factors that disrupt these protein complexes, may offer valuable insights for developing innovative therapeutic strategies against cancer.

MATR3 promotes liver cancer progression by suppressing DHX58-mediated type I interferon response

MATR3 is a nuclear matrix protein implicated in various cancers; however, its specific role in tumor progression remains unclear. The study utilized the TCGA database to reveal that MATR3 expression is upregulated in liver cancer and is correlated with poor prognosis. Functionally, MATR3 promoted liver cancer cell proliferation and metastasis. Comprehensive RNA sequencing analysis showed that MATR3 significantly affected the type I IFN signaling pathway and DHX58 is a downstream target of MATR3. Further experiments showed that MATR3 bound to DHX58 mRNA through its RRM structural domain and recruited YTHDF2, an m6A reader, leading to degradation of DHX58 mRNA and suppression of the type I IFN signaling pathway. The knockout of MATR3 in liver cancer cells triggered a natural immune response that stimulated CD8+ T cells to eliminate liver cancer cells. This study demonstrated that MATR3 downregulates type I IFN signaling in liver cancer cells through m6A modification and inhibits immune cell infiltration within tumors. These findings expand our understanding of the role of MATR3 in liver cancer.

MYC and HSF1 Cooperate to Drive PLK1 inhibitor Sensitivity in High Grade Serous Ovarian Cancer

Ovarian cancer is a deadly female cancer with high rates of recurrence. The primary treatment strategy for patients is platinum-based therapy regimens that almost universally develop resistance. Consequently, new therapeutic avenues are needed to overcome the plateau that current therapies have on patient outcomes. We describe a gene amplification involving both HSF1 and MYC, wherein these two genes on chromosome 8q are co-amplified in over 7% of human tumors that is enriched to over 30% of patients with ovarian cancer. We further found that HSF1 and MYC transcriptional activity is correlated in human tumors and ovarian cancer cell lines, suggesting they may cooperate in ovarian cancer cells. CUT&RUN for HSF1 and MYC in co-amplified ovarian cancer cells revealed that HSF1 and MYC have overlapping binding at a substantial number of locations throughout the genome where their binding peaks are near identical. Consistent with these data, a protein-protein interaction between HSF1 and MYC was detected in ovarian cancer cells, implying these two transcription factors have a molecular cooperation. Further supporting their cooperation, growth of HSF1-MYC co-amplified ovarian cancer cells were found to be dependent on both HSF1 and MYC. In an attempt to identify a therapeutic target that could take advantage of this dependency on both HSF1 and MYC, PLK1 was identified as being correlated with HSF1 and MYC in primary human tumor specimens, consistent with a previously established effect of PLK1 on HSF1 and MYC protein levels. Targeting PLK1 with the compound volasertib (BI-6727) revealed a greater than 200-fold increased potency of volasertib in HSF1-MYC co-amplified ovarian cancer cells compared to ovarian cancer cells wild-type HSF1 and MYC copy number, which extended to several growth assays, including spheroid growth. Volasertib, and other PLK1 inhibitors, have not shown great success in clinical trials and this study suggests that targeting PLK1 may be viable in a precision medicine approach using HSF1-MYC co-amplification as a biomarker for response.

Prognostic and Predictive Potential of CCL5 Expression in Muscle-Invasive Bladder Cancer Patients

Bladder cancer (BC) is the 12th most commonly diagnosed cancer worldwide. Although there are several well-established molecular and immunological classifications, prognostic and predictive markers for tumor cells and immune cells are still needed. Using a tissue microarray, we analyzed the expression of the chemokine CC motif ligand 5 (CCL5) by immunohistochemistry (IHC) in 175 muscle-invasive BC samples. The application of a single cutoff for the staining status of tumor cells (TCs; positive vs. negative) and immune cells (ICs; positive vs. negative) revealed 75 patients (42.9%) and 123 patients (70.3%) with CCL5-positive TCs or ICs, respectively. IHC results were associated with prognostic and predictive data. Multivariate Cox regression analysis revealed that positive CCL5 staining in TCs was associated with significantly shorter disease-specific survival (DSS; RR = 1.51; p = 0.047), but CCL5-negative ICs were associated with significantly shorter overall survival (OS; RR = 1.66; p = 0.005), DSS (RR = 2.02; p = 0.001) and recurrence-free survival (RFS; RR = 1.94; p = 0.002). Adjuvant chemotherapy was favorable for patients with CCL5-negative ICs for OS (RR = 0.30; p = 0.006), DSS (RR = 0.36; p = 0.022) and RFS (RR = 0.41; p = 0.046) but not for patients with CCL5-positive ICs, except in the subgroup of N1 + N2 patients, where it was associated with better OS. We suggest that CCL5 expression can be a prognostic and predictive marker for muscle-invasive bladder cancer patients.

Immune Cell Migration to Cancer

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

NK cell transfer overcomes resistance to PD-(L)1 therapy in aged mice

BACKGROUND

Cancer is the leading cause of death among older adults. Although the integration of immunotherapy has revolutionized the therapeutic landscape of cancer, the complex interactions between age and immunotherapy efficacy remain incompletely defined. Here, we aimed to elucidate the relationship between aging and immunotherapy resistance.

METHODS

Flow cytometry was performed to evaluate the infiltration of immune cells in the tumor microenvironment (TME). In vivo T cell proliferation, cytotoxicity and migration assays were performed to evaluate the antitumor capacity of tumor antigen-specific CD8+ T cells in mice. Real-time quantitative PCR (qPCR) was used to investigate the expression of IFN-γ-associated gene and natural killer (NK)-associated chemokine. Adoptive NK cell transfer was adopted to evaluate the effects of NK cells from young mice in overcoming the immunotherapy resistance of aged mice.

RESULTS

We found that elderly patients with advanced non-small cell lung cancer (aNSCLC) aged ≥ 75 years exhibited poorer progression-free survival (PFS), overall survival (OS) and a lower clinical response rate after immunotherapy. Mechanistically, we showed that the infiltration of NK cells was significantly reduced in aged mice compared to younger mice. Furthermore, the aged NK cells could also suppress the activation of tumor antigen-specific CD8+ T cells by inhibiting the recruitment and activation of CD103+ dendritic cells (DCs). Adoptive transfer of NK cells from young mice to aged mice promoted TME remodeling, and reversed immunotherapy resistance.

CONCLUSION

Our findings revealed the decreased sensitivity of elderly patients to immunotherapy, as well as in aged mice. This may be attributed to the reduction of NK cells in aged mice, which inhibits CD103+ DCs recruitment and its CD86 expression and ultimately leads to immunotherapy resistance.

Comprehensive analysis of human tissues reveals unique expression and localization patterns of HSF1 and HSF2

Heat shock factors (HSFs) are the main transcriptional regulators of the evolutionarily conserved heat shock response. Beyond cell stress, several studies have demonstrated that HSFs also contribute to a vast variety of human pathologies, ranging from metabolic diseases to cancer and neurodegeneration. Despite their evident role in mitigating cellular perturbations, the functions of HSF1 and HSF2 in physiological proteostasis have remained inconclusive. Here, we analyzed a comprehensive selection of paraffin-embedded human tissue samples with immunohistochemistry. We demonstrate that both HSF1 and HSF2 display distinct expression and subcellular localization patterns in benign tissues. HSF1 localizes to the nucleus in all epithelial cell types, whereas nuclear expression of HSF2 was limited to only a few cell types, especially the spermatogonia and the urothelial umbrella cells. We observed a consistent and robust cytoplasmic expression of HSF2 across all studied smooth muscle and endothelial cells, including the smooth muscle cells surrounding the vasculature and the high endothelial venules in lymph nodes. Outstandingly, HSF2 localized specifically at cell-cell adhesion sites in a broad selection of tissue types, such as the cardiac muscle, liver, and epididymis. To the best of our knowledge, this is the first study to systematically describe the expression and localization patterns of HSF1 and HSF2 in benign human tissues. Thus, our work expands the biological landscape of these factors and creates the foundation for the identification of specific roles of HSF1 and HSF2 in normal physiological processes.

Knockdown of SQLE promotes CD8+ T cell infiltration in the tumor microenvironment

Cholesterol biosynthesis and metabolism are critical aspects that shape the process of tumor development and associated microenvironmental conditions owing to the ability of cholesterol to drive tumor growth and invasion. Squalene Epoxidase (SQLE) is the second rate-limiting enzyme involved in the synthesis of cholesterol. The functional role of SQLE within the tumor microenvironment, however, has yet to be established. Here we show that SQLE is distinctively expressed across most types of cancer, and the expression level is highly correlated with tumor mutation burden and microsatellite instability. Accordingly, SQLE was identified as a prognostic risk factor in cancer patients. In addition, we observed a negative correlation between SQLE expression and immune cell infiltration across multiple cancers, and murine xenograft model further confirmed that SQLE knockdown was associated with enhanced intratumoral CD8+ T cell infiltration. Using next-generation sequencing, we identified 410 genes distinctively expressed in tumors exhibiting SQLE inhibition. KEGG and GO analysis further verified that SQLE altered the immune response in the tumor microenvironment. Furthermore, we found that the metabolism and translation of proteins is the main binding factor with SQLE. Our findings ascertain that SQLE is a potential target in multiple cancers and suppressing SQLE establishes an essential mechanism for shaping tumor microenvironment.