Secretion of cytokines and heat shock protein (HspA1A) by ovarian cancer cells depending on the tumor type and stage of disease

The Role of Extracellular HSP70 in the Function of Tumor-Associated Immune Cells

Simple Summary

The intracellular heat shock protein 70 (HSP70) is essential for cells to respond to stress, for instance, by refolding damaged proteins or inhibiting apoptosis. However, in cancer, HSP70 is overexpressed and can translocate to the extracellular milieu, where it emerged as an important modulator of tumor-associated immune cells. By targeting the tumor microenvironment (TME) through different mechanisms, extracellular HSP70 can trigger pro- or anti-tumorigenic responses. Therefore, understanding the pathways and their consequences is crucial for therapeutically targeting cancer and its surrounding microenvironment. In this review, we summarize current knowledge on the translocation of extracellular HSP70. We further elucidate its functions within the TME and provide an overview of potential therapeutic options.

Abstract

Extracellular vesicles released by tumor cells (T-EVs) are known to contain danger-associated molecular patterns (DAMPs), which are released in response to cellular stress to alert the immune system to the dangerous cell. Part of this defense mechanism is the heat shock protein 70 (HSP70), and HSP70-positive T-EVs are known to trigger anti-tumor immune responses. Moreover, extracellular HSP70 acts as an immunogen that contributes to the cross-presentation of major histocompatibility complex (MHC) class I molecules. However, the release of DAMPs, including HSP70, may also induce chronic inflammation or suppress immune cell activity, promoting tumor growth. Here, we summarize the current knowledge on soluble, membrane-bound, and EV-associated HSP70 regarding their functions in regulating tumor-associated immune cells in the tumor microenvironment. The molecular mechanisms involved in the translocation of HSP70 to the plasma membrane of tumor cells and its release via exosomes or soluble proteins are summarized. Furthermore, perspectives for immunotherapies aimed to target HSP70 and its receptors for cancer treatment are discussed and presented.

Sequenced Combinations of Cisplatin and Selected Phytochemicals towards Overcoming Drug Resistance in Ovarian Tumour Models

In the present study, cisplatin, artemisinin, and oleanolic acid were evaluated alone, and in combination, on human ovarian A2780, A2780^ZD0473R, and A2780^cisR cancer cell lines, with the aim of overcoming cisplatin resistance and side effects. Cytotoxicity was assessed by MTT reduction assay. Combination index (CI) values were used as a measure of combined drug effect. MALDI TOF/TOF MS/MS and 2-DE gel electrophoresis were used to identify protein biomarkers in ovarian cancer and to evaluate combination effects. Synergism from combinations was dependent on concentration and sequence of administration. Generally, bolus was most synergistic. Moreover, 49 proteins differently expressed by 2 ≥ fold were: CYPA, EIF5A1, Op18, p18, LDHB, P4HB, HSP7C, GRP94, ERp57, mortalin, IMMT, CLIC1, NM23, PSA3,1433Z, and HSP90B were down-regulated, whereas hnRNPA1, hnRNPA2/B1, EF2, GOT1, EF1A1, VIME, BIP, ATP5H, APG2, VINC, KPYM, RAN, PSA7, TPI, PGK1, ACTG and VDAC1 were up-regulated, while TCPA, TCPH, TCPB, PRDX6, EF1G, ATPA, ENOA, PRDX1, MCM7, GBLP, PSAT, Hop, EFTU, PGAM1, SERA and CAH2 were not-expressed in A2780^cisR cells. The proteins were found to play critical roles in cell cycle regulation, metabolism, and biosynthetic processes and drug resistance and detoxification. Results indicate that appropriately sequenced combinations of cisplatin with artemisinin (ART) and oleanolic acid (OA) may provide a means to reduce side effects and circumvent platinum resistance.

The Role of Tumor-Associated Macrophages in the Progression and Chemoresistance of Ovarian Cancer

Tumor-associated macrophages (TAMs) constitute the main population of immune cells present in the ovarian tumor microenvironment. These cells are characterized by high plasticity and can be easily polarized by colony-stimulating factor-1, which is released by tumor cells, into an immunosuppressive M2-like phenotype. These cells are strongly implicated in both the progression and chemoresistance of ovarian cancer. The main pro-tumoral function of M2-like TAMs is the secretion of a variety of cytokines, chemokines, enzymes and exosomes that reach microRNAs, directly inducing the invasion potential and chemoresistance of ovarian cancer cells by triggering their pro-survival signaling pathways. The M2-like TAMs are also important players in the metastasis of ovarian cancer cells in the peritoneum through their assistance in spheroid formation and attachment of cancer cells to the metastatic area—the omentum. Moreover, TAMs interplay with other immune cells, such as lymphocytes, natural killer cells, and dendritic cells, to inhibit their responsiveness, resulting in the development of immunosuppression. The detrimental character of the M2-like type of TAMs in ovarian tumors has been confirmed by a number of studies, demonstrating the positive correlation between their high level in tumors and low overall survival of patients.

Synergistic enhancement of efficacy of platinum drugs with verteporfin in ovarian cancer cells

Background

Epithelial ovarian cancers (EOCs) comprises the majority of malignant ovarian neoplasms. Combination treatment with chemotherapeutic agents seems to be a promising strategy in ovarian cancer (OVCA) patients in order to overcome drug resistance. In this in vitro study, we investigated the therapeutic efficacy of verteporfin (VP) alone and in combination with cisplatin (CDDP), carboplatin (CP) and paclitaxel (Taxol). The main objectives of this study are to determine the nature of interactions between VP and CDDP/CP/Taxol and to understand the mechanism of action of VP in OVCA cells.

Methods

The efficacy of VP on cell proliferation, cytotoxicity, invasion and clonogenic capacity was assayed in CDDP-sensitive (COV504, OV-90) and CDDP-resistant (A2780Cis) cell lines. The cytotoxic effects of drugs either alone or in combination were evaluated using MTT assay and Cell Viability Blue assay. The effects of drugs on the metabolic functions were studied using matrigel invasion assay and clonogenic assay. Immunoblot analysis was carried out to investigate changes in YAP and cell cycle genes. Changes in the cytokines due to drug treatments were analyzed using a cytokine array.

Results

Treatment with VP inhibited cell proliferation, invasion and increased cytotoxicity of OVCA cells. We observed that VP chemosensitized CDDP-resistant cells, even at lower doses. When added either in constant or non-constant ratios, VP produced synergistic effects in combination with CDDP/CP/Taxol. A cytokine array identified upregulation of cytokines in OVCA cells that were inhibited by VP treatment.

Conclusions

Either in cisplatin-resistant cell lines or cisplatin-sensitive cell lines, VP proves to be more efficient in inhibiting cell proliferation and inducing cytotoxicity. Our results suggest that novel combinations of VP with CDDP or CP or Taxol might be an attractive therapeutic strategy to enhance OVCA chemosensitivity. The fact that lower doses of VP are effective in chemosensitizing the CDDP-resistant cells, might ultimately lead to the development of an innovative combination therapy for the treatment of OVCA patients.

LASP1 promotes proliferation, metastasis, invasion in head and neck squamous cell carcinoma and through direct interaction with HSPA1A

LIM and SH3 protein 1 (LASP1) is a specific focal adhesion protein that promotes metastasis in a variety of tumours. However, its role in head and neck squamous cell carcinoma (HNSCC) has not been fully validated. The purpose of this study was to analyse the interaction of LASP1 and its binding partner in HNSCC. The expression of LASP1 and HSPA1A in HNSCC was analysed by real-time PCR and Western blot. The effects of LASP1 on the biology behaviour of HNSCC cell lines were observed in vivo and in vitro. Co-immunoprecipitation analysis was performed to confirm the interaction between LASP1 and HSPA1A. LASP1 was highly expressed in HNSCC and associated with poor prognosis for patients. LASP1 also promoted cell proliferation, colony formation, invasion and cell cycle G2/M phase transition. Heat shock protein family A member 1A (HSPA1A) is identified as a chaperone protein of LASP1 and co-localized in the cytoplasm. HSPA1A positively regulates the interaction of LASP1 with P-AKT and enhances the malignant behaviour of HNSCC cells. LASP1 and HSPA1A are both up-regulated in HNSCC, and directly binds to each other. Double inhibition of LASP1 and HSPA1A expression may be an effective method for the treatment of HNSCC.

Scientific reports concerning the impact of interleukin 4, interleukin 10 and transforming growth factor β on cancer cells

Cytokines are signalling proteins generated in most part by immune cells that have critical functions in cellular lifespan. Here we present recent data on three selected anti-inflammatory cytokines: interleukin (IL)-10, IL-4 and transforming growth factor β (TGF-β). IL-10 inhibits the synthesis of major pro-inflammatory cytokines, chemokines, and mediates anti-inflammatory reactions. IL-4 is a multifunctional cytokine which plays a crucial role in the regulation of immune responses and is involved in processes associated with development and differentiation of lymphocytes and regulation of T cell survival. Transforming TGF-β, which in normal cells or pre-cancerous cells, promotes proliferation arrest which represses tumour growth. In this review, we focus on the influence of IL-10, IL-4 and TGF-β on various types of cancer as well as potential of these selected cytokines to serve as new biomarkers which can support effective therapies for cancer patients. This article is presented based on a review of the newest research results.

Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells

PURPOSE

The aim of this study was to evaluate the influence of ovarian cancer cell lysates isolated from type I or type II ovarian cancer (OC) on the phenotype of monocyte-derived dendritic cells (Mo-DCs) and the cytokine profile. We also determined whether the Mo-DCs and tumor microenvironment, reflected by peritoneal fluid (PF) from type I or II ovarian cancer, could promote regulatory T cell (Tregs) differentiation from naive CD4⁺ lymphocytes in vitro.

RESULTS

Our results show a significant role of the ovarian cancer microenvironment reflected by PF from type I or II OC in the inhibition of the DC differentiation process. Interestingly, the percentage of cells co-expressing CD45 and CD14 antigens in the cultures stimulated with PF from both type I and type II OC was higher than in the control. Furthermore, the percentage of cells expressing CD1a, i.e., a marker of immature DCs, was significantly reduced in the cultures stimulated with PF from type I and type II OC. The results obtained show that ovarian cancer type II lysates induce differentiation of monocytes into macrophage-like cells with a CD1a⁺/HLA-DR⁺/CD83⁻ phenotype and significantly higher CD86/HLA-DR expression. We show that ovarian cancer type II Mo-DCs are able to prevent an immune response by release of IL-10, whereas OC type I Mo-DCs can promote the generation of Tregs.

CONCLUSIONS

We demonstrate that each type of ovarian cancer can induce a unique phenotype of DCs and differentiation of Tregs, both associated with immune-suppressive function, which may be an obstacle while developing effective anticancer dendritic cell vaccination.