Galectin-9 induces apoptosis in OVCAR-3 ovarian cancer cell through mitochondrial pathway

Immunomodulation by galectin-9: Distinct role in T cell populations, current therapeutic avenues and future potential

Galectins, glycan-binding proteins, have been identified as critical regulators of the immune system. Recently, Galectin-9 (Gal-9) has emerged as biomarker that correlates with disease severity in a range of inflammatory conditions. However, Gal-9 has highly different roles in the context of immunoregulation, with the potential to either stimulate or suppress the immune response. Neutralizing antibodies targeting Gal-9 have been developed and are in early test phase investigating their therapeutic potential in cancer. Despite ongoing research, the mechanisms behind Gal-9 action remain not fully understood, and extrapolating the implications of targeting this molecule from previous studies is challenging. Here, we examine the pleiotropic function of Gal-9 focusing on conventional T lymphocytes, providing a current overview of its immunostimulatory and immunosuppressive roles. In particular, we highlight that Gal-9 differentially regulates immune responses depending on the context. Considering this complexity, further investigation of Gal-9's intricate biology is necessary to define therapeutic strategies in immune disorders and cancer treatment aimed at inducing or inhibiting Gal-9 signaling.

α2β1 Integrin specific inhibitor BTT-3033 promotes paclitaxel-induced apoptosis in human ovarian cancer cells

Background and purpose

The new plan of using molecular targeted agents in combination with cytotoxic drugs may represent a promising strategy to increase the efficacy of chemotherapy. Hence, we examined whether α2β1 integrin-specific inhibitor, BTT-3033, could modulate the susceptibility of OVCAR3 and SKOV3 ovarian cancer cells to paclitaxel (PTX).

Experimental approach

Ovarian cancer cell lines were treated with BTT-3033 and different concentrations of PTX. To determine the mechanisms involved in the PTX/BTT-3033 combination-induced cell death, cell viability, apoptosis, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), and caspase-3 activity were evaluated.

Findings/Results

Both BTT-3033 (≥ 1 μM) and PTX (≥ 0.01 μM) suppressed the proliferation of OVCAR3 and SKOV3 cells in a concentration-related manner. Pretreatment with BTT-3033 (1 μM), followed by PTX-induced synergistic antiproliferative effects, decreased the IC50 values of PTX from 0.45 to 0.03 μM in OVCAR3 and 0.35 to 0.02 μM in SKOV3 cells. All of the coefficients of drug interaction for various PTX and BTT-3033 combinations were found to be less than 1. Moreover, PTX/BTT-3033 combination induced more apoptotic cells (from 4.2% to 87.0% in OVCAR3 and 2.4% to 88.5% in SKOV3) than PTX alone. Combination therapy also decreased MMP and increased the caspase-3 activity. Additionally, we found that the PTX/BTT-3033 combination enhanced ROS production in OVCAR3 and SKOV3 cells.

Conclusion and implications

BTT-3033 has demonstrated the ability to enhance the susceptibility of ovarian cancer cells to PTX by inducing MMP loss, ROS production, and mitochondrial apoptosis, therefore this combination therapy might represent a promising strategy for ovarian cancer treatment.

Expression of Intracellular Galectin-8 and -9 in Endometrial Cancer

Endometrial cancer (EC) is a common gynecological cancer worldwide. Treatment has been improved in recent years; however, in advanced stages, therapeutic options are still limited. The expression of galectins is increased in several tumor types and that they are involved in important cell processes. Large studies on endometrial cancer are still pending; Specimens of 225 patients with EC were immunohistochemically stained with antibodies for Gal-8 and Gal-9. Expression was correlated with histopathological variables. The cytosolic expression of both galectins is associated with grading and survival. Cytosolic Galectin-8 expression is a positive prognostic factor for overall survival (OS) and progression-free survival (PFS), while nuclear Gal-8 expression correlates only to OS. The cytosolic presence of Galectin-9 is correlated with a better prognosis regarding OS. Our results suggest that expression of both galectins is associated with OS and PFS in EC. Further studies are needed to understand the underlying molecular mechanisms.

The effects of chitosan-loaded JQ1 nanoparticles on OVCAR-3 cell cycle and apoptosis-related gene expression

Background and purpose

Ovarian cancer is the deadliest gynecological cancer. Bromodomain and extra terminal domain (BET) proteins play major roles in the regulation of gene expression at the epigenetic level. Jun Qi (JQ1) is a potent inhibitor of BET proteins. Regarding the short half-life and poor pharmacokinetic profile, JQ1 was loaded into newly developed nano-carriers. Chitosan nanoparticles are one of the best and potential polymers in cancer treatment. The present study aimed to build chitosan-JQl nanoparticles (Ch-J-NPs), treat OVCAR-3 cells with Ch-J-NPs, and evaluate the effects of these nanoparticles on cell cycle and apoptosis-associated genes.

Experimental approach

Ch-J-NPs were synthesized and characterized. The size and morphology of Ch-J-NPs were defined by DLS and FE-SEM techniques. OVCAR-3 cells were cultured and treated with Ch-J-NPs. Then, IC50 was measured using MTT assay. The groups were defined and cells were treated with IC50 concentration of Ch-J-NPs, for 48 h. Finally, cells in different groups were assessed for the expression of genes of interest using quantitative RT-PCR.

Findings/Results

IC50 values for Ch-J-NPs were 5.625 μg/mL. RT-PCR results demonstrated that the expression of genes associated with cell cycle activity (c-MYC, hTERT, CDK1, CDK4, and CDK6) was significantly decreased following treatment of cancer cells with Ch-J-NPs. Conversely, the expression of caspase-3, and caspase-9 significantly increased. BAX (pro-apoptotic) to BCL2 (anti-apoptotic) expression ratio, also increased significantly after treatment of cells with Ch-J-NPs.

Conclusion and implications

Ch-J-NPs showed significant anti-cell cyclic and apoptotic effects on OVCAR-3 cells.

Galectin-9 is a target for the treatment of cancer: A patent review

Galectins, which correspond to a group of proteins capable of recognizing and reversibly binding to β-galactoside carbohydrates, have been the subject of innovation and development of technological products. Galectins play biological roles, such as cell proliferation and apoptosis, and some studies showed differences in the concentrations of galectins dispersed in serum of patients with cancer. For this reason, different studies have evaluated the biotechnological potential of these proteins as biomarkers for the prognosis and/or diagnosis of physiological disorders. Thus, this review discusses recent technological advancements in targeting galectins for the treatment of cancer and using galectins for cancer prognosis and diagnosis. Data mining was performed using the search descriptors "Galectin 9* and cancer*" and the ESPACENET and Cortellis Drug Discovery Intelligence (CDDI) databases. PRISMA guidelines were followed as a basis for literature review which aimed to conduct a systematic study of galectin-9 patents related to cancer prognosis, diagnosis and treatment. Results showed the importance of galectin-9 protein patents in furthering biomedical advancements in the global fight against cancer.

Galectin-9 has non-apoptotic cytotoxic activity toward acute myeloid leukemia independent of cytarabine resistance

Acute myeloid leukemia (AML) is a malignancy still associated with poor survival rates, among others, due to frequent occurrence of therapy-resistant relapse after standard-of-care treatment with cytarabine (AraC). AraC triggers apoptotic cell death, a type of cell death to which AML cells often become resistant. Therefore, therapeutic options that trigger an alternate type of cell death are of particular interest. We previously identified that the glycan-binding protein Galectin-9 (Gal-9) has tumor-selective and non-apoptotic cytotoxicity towards various types of cancer, which depended on autophagy inhibition. Thus, Gal-9 could be of therapeutic interest for (AraC-resistant) AML. In the current study, treatment with Gal-9 was cytotoxic for AML cells, including for CD34⁺ patient-derived AML stem cells, but not for healthy cord blood-derived CD34⁺ stem cells. This Gal-9-mediated cytotoxicity did not rely on apoptosis but was negatively associated with autophagic flux. Importantly, both AraC-sensitive and -resistant AML cell lines, as well as AML patient samples, were sensitive to single-agent treatment with Gal-9. Additionally, Gal-9 potentiated the cytotoxic effect of DNA demethylase inhibitor Azacytidine (Aza), a drug that is clinically used for patients that are not eligible for intensive AraC treatment. Thus, Gal-9 is a potential therapeutic agent for the treatment of AML, including AraC-resistant AML, by inducing caspase-independent cell death.

The interrelation of galectins and autophagy

Autophagy is a vital physiological process that maintains intracellular homeostasis by removing damaged organelles and senescent or misfolded molecules. However, excessive autophagy results in cell death and apoptosis, which will lead to a variety of diseases. Galectins are a type of animal lectin that binds to β-galactosides and can bind to the cell surface or extracellular matrix glycans, affecting a variety of immune processes in vivo and being linked to the development of many diseases. In many cases, galectins and autophagy both play important regulatory roles in the cellular life course, yet our understanding of the relationship between them is still incomplete. Galectins and autophagy may share common etiological cofactors for some diseases. Hence, we summarize the relationship between galectins and autophagy, aiming to draw attention to the existence of multiple associations between galectins and autophagy in a variety of physiological and pathological processes, which provide new ideas for etiological diagnosis, drug development, and therapeutic targets for related diseases.

Galectins and galectin-mediated autophagy regulation: new insights into targeted cancer therapy

Galectins are animal lectins with specific affinity for galactosides via the conserved carbohydrate recognition domains. Increasing studies recently have identified critical roles of galectin family members in tumor progression. Abnormal expression of galectins contributes to the proliferation, metastasis, epithelial-mesenchymal transformation (EMT), immunosuppression, radio-resistance and chemoresistance in various cancers, which has attracted cumulative clinical interest in galectin-based cancer treatment. Galectin family members have been reported to participate in autophagy regulation under physiological conditions and in non-tumoral diseases, and implication of galectins in multiple processes of carcinogenesis also involves regulation of autophagy, however, the relationship between galectins, autophagy and cancer remains largely unclear. In this review, we introduce the structure and function of galectins at the molecular level, summarize their engagements in autophagy and cancer progression, and also highlight the regulation of autophagy by galectins in cancer as well as the therapeutic potentials of galectin and autophagy-based strategies. Elaborating on the mechanism of galectin-regulated autophagy in cancers will accelerate the exploitation of galectins-autophagy targeted therapies in treatment for cancer.

Galectin functions in cancer-associated inflammation and thrombosis

Galectins are carbohydrate-binding proteins that regulate many cellular functions including proliferation, adhesion, migration, and phagocytosis. Increasing experimental and clinical evidence indicates that galectins influence many steps of cancer development by inducing the recruitment of immune cells to the inflammatory sites and modulating the effector function of neutrophils, monocytes, and lymphocytes. Recent studies described that different isoforms of galectins can induce platelet adhesion, aggregation, and granule release through the interaction with platelet-specific glycoproteins and integrins. Patients with cancer and/or deep-venous thrombosis have increased levels of galectins in the vasculature, suggesting that these proteins could be important contributors to cancer-associated inflammation and thrombosis. In this review, we summarize the pathological role of galectins in inflammatory and thrombotic events, influencing tumor progression and metastasis. We also discuss the potential of anti-cancer therapies targeting galectins in the pathological context of cancer-associated inflammation and thrombosis.

Galectin Family Members: Emerging Novel Targets for Lymphoma Therapy?

The galectin family of proteins has high affinity with β-galactoside-containing glycans. These proteins participate in cell growth and differentiation, cell adhesion, cell signal transduction, cell apoptosis, and other cellular activities. In recent years, a large number of studies have described the expression and correlation of galectins in different tumors. Each member of the family plays a vital role in tumor growth, progression, angiogenesis, adhesion, and tumor immune escape. Studies on the roles of galectins in lymphoma have mainly involved galectin-1, -3, -7, and -9. The results suggest that galectins may become novel targets for precise tumor treatment. This article reviews current research progress regarding galectins in lymphoma and provides new ideas for exploring them as novel targets for treating lymphoma and other important medical issues.

Galectin-8 and -9 as prognostic factors for cervical cancer

Purpose

Galectins are carbohydrate-binding proteins with multiple effects on cell biology. Research shows that they play an important role in tumor development and progression. Therefore, in this study, the presence of Galectin-8 and -9 (Gal), both already known as prognostic factors in other tumor entities, were investigated in cervical cancer. Our aim was to examine the association of Gal-8 and -9 expression with histopathological markers and survival of the patients.

Methods

Gal-8 and -9 expression was investigated in 250 cervical cancer samples by immunohistochemistry. The staining was evaluated using the immunoreactive score (IRS). The results were correlated to clinical and pathological data. The correlation of Gal-8 and -9 expression with overall and relapse-free survival was analyzed.

Results

Expression of Gal-8 was associated with negative N-status and lower FIGO status. Detection of Gal-9 was connected to negative N-status and lower grading regarding all specimens. A correlation of Gal-9 with lower FIGO status was detected for squamous cell carcinoma (SCC) only. Expression of Gal-8 was associated with relapse-free survival of SCC patients in a positive manner. Gal-9 expression was associated with better overall survival.

Conclusion

Our results suggest that expression of both galectins is inversely associated with tumor stage and progression. Gal-8 expression is associated with relapse-free survival of patients with SCC, while presence of Gal-9 in cervical cancer is associated with a better prognosis in regard of overall survival.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-022-06449-9.

Galectin-9 inhibits cell proliferation and induces apoptosis in Jurkat and KE-37 acute lymphoblastic leukemia cell lines via caspase-3 activation

Background and purpose:

Acute lymphoblastic leukemia (ALL) is a type of cancer of blood and bone marrow characterized by abnormal proliferation of lymphoid progenitor cells. Galectin-9 is a tandem-repeat type galectin expressed in various tumor cells. It seems that the connection between galectin-9 and T cell immunoglobulin mucin-3 receptor acts as a negative regulator of cancer cells proliferation.

Experimental approach:

In this research, the effects of galectin-9 were investigated using MTS cell proliferation colorimetric, colony-forming, annexin V-FITC/PI, and caspase-3 assays in the Jurkat and KE-37 cell lines of ALL. Furthermore, the western blotting technique was used to evaluate the levels of apoptotic proteins such as Bax and Bcl-2 in these cell lines.

Findings/Results:

Our results indicated that galectin-9 can considerably reduce the cell growth and colony formation ability of both Jurkat and KE-37 cell lines in a concentration-dependent manner. Besides, galectin-9 induced apoptosis in a concentration-dependent manner in ALL cells by a mechanism associated with Bax/Bcl-2 expression and activation of the caspase-3 activation.

Conclusion and implications:

Galectin-9 inhibited the growth and proliferation of cell lines with increased programmed cell death, therefore it can be considered as a potential factor in the progression of ALL therapeutics that needs more research in this context.

Glycan-Lectin Interactions in Cancer and Viral Infections and How to Disrupt Them

Glycan-lectin interactions play an essential role in different cellular processes. One of their main functions is involvement in the immune response to pathogens or inflammation. However, cancer cells and viruses have adapted to avail themselves of these interactions. By displaying specific glycosylation structures, they are able to bind to lectins, thus promoting pathogenesis. While glycan-lectin interactions promote tumor progression, metastasis, and/or chemoresistance in cancer, in viral infections they are important for viral entry, release, and/or immune escape. For several years now, a growing number of investigations have been devoted to clarifying the role of glycan-lectin interactions in cancer and viral infections. Various overviews have already summarized and highlighted their findings. In this review, we consider the interactions of the lectins MGL, DC-SIGN, selectins, and galectins in both cancer and viral infections together. A possible transfer of ways to target and disrupt them might lead to new therapeutic approaches in different pathological backgrounds.

Galectin-9 as a biomarker of disease severity

Galectin-9 (Gal-9) is a β-galactoside binding lectin known for its immunomodulatory role in various microbial infections. Gal-9 is expressed in all organ systems and localized in the nucleus, cell surface, cytoplasm and the extracellular matrix. It mediates host-pathogen interactions and regulates cell signalling via binding to its receptors. Gal-9 is involved in many physiological functions such as cell growth, differentiation, adhesion, communication and death. However, recent studies have emphasized on the elevated levels of Gal-9 in autoimmune disorders, viral infections, parasitic invasion, cancer, acute liver failure, atopic dermatitis, chronic kidney disease, type-2 diabetes, coronary artery disease, atherosclerosis and benign infertility-related gynecological disorders. In this paper we have reviewed the potential of Gal-9 as a reliable, sensitive and non-invasive biomarker of disease severity. Tracking changes in Gal-9 levels and its implementation as a biomarker in clinical practice will be an important tool to monitor disease activity and facilitate personalized treatment decisions.

Galectins and Ovarian Cancer

Ovarian cancer is known for its aggressive pathological features, including the capacity to undergo epithelial to mesenchymal transition, promoting angiogenesis, metastatic potential, chemoresistance, inhibiting apoptosis, immunosuppression and promoting stem-like features. Galectins, a family of glycan-binding proteins defined by a conserved carbohydrate recognition domain, can modulate many of these processes, enabling them to contribute to the pathology of ovarian cancer. Our goal herein was to review specific galectin members identified in the context of ovarian cancer, with emphasis on their association with clinical and pathological features, implied functions, diagnostic or prognostic potential and strategies being developed to disrupt their negative actions.

Understanding and Targeting Apoptotic Pathways in Ovarian Cancer

Ovarian cancer cells evade the immune system as well as chemotherapeutic and/or biologic treatments through inherent or acquired mechanisms of survival and drug resistance. Depending on the cell type and the stimuli, this threshold can range from external forces such as blunt trauma to programmed processes such as apoptosis, autophagy, or necroptosis. This review focuses on apoptosis, which is one form of programmed cell death. It highlights the multiple signaling pathways that promote or inhibit apoptosis and reviews current clinical therapies that target apoptotic pathways in ovarian cancer.