A novel radioresistant mechanism of galectin-1 mediated by H-Ras-dependent pathways in cervical cancer cells

Ras-Targeting Stabilized Peptide Increases Radiation Sensitivity of Cancer Cells

Radiation therapy is one of the most common treatments for cancer. However, enhancing tumors' radiation sensitivity and overcoming tolerance remain a challenge. Previous studies have shown that the Ras signaling pathway directly influences tumor radiation sensitivity. Herein, we designed a series of Ras-targeting stabilized peptides, with satisfactory binding affinity (KD = 0.13 μM with HRas) and good cellular uptake. Peptide H5 inhibited downstream phosphorylation of ERK and increased radio-sensitivity in HeLa cells, resulting in significantly reduced clonogenic survival. The stabilized peptides, designed with an N-terminal nucleation strategy, acted as potential radio-sensitizers and broadened the applications of this kind of molecule. This is the first report of using stabilized peptides as radio-sensitizers, broadening the applications of this kind of molecule.

Regulation of Nrf2/Keap1 signaling pathway in cancer drug resistance by galectin-1: cellular and molecular implications

Oxidative stress is characterized by the deregulation of the redox state in the cells, which plays a role in the initiation of various types of cancers. The activity of galectin-1 (Gal-1) depends on the cell redox state and the redox state of the microenvironment. Gal-1 expression has been related to many different tumor types, as it plays important roles in several processes involved in cancer progression, such as apoptosis, cell migration, adhesion, and immune response. The erythroid-2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) signaling pathway is a crucial mechanism involved in both cell survival and cell defense against oxidative stress. In this review, we delve into the cellular and molecular roles played by Gal-1 in the context of oxidative stress onset in cancer cells, particularly focusing on its involvement in activating the Nrf2/Keap1 signaling pathway. The emerging evidence concerning the anti-apoptotic effect of Gal-1, together with its ability to sustain the activation of the Nrf2 pathway in counteracting oxidative stress, supports the role of Gal-1 in the promotion of tumor cells proliferation, immuno-suppression, and anti-tumor drug resistance, thus highlighting that the inhibition of Gal-1 emerges as a potential strategy for the restraint and regression of tumor progression. Overall, a deeper understanding of the multi-functionality and disease-specific expression profiling of Gal-1 will be crucial for the design and development of novel Gal-1 inhibitors as anticancer agents. Excitingly, although it is still understudied, the ever-growing knowledge of the sophisticated interplay between Gal-1 and Nrf2/Keap1 will enable researchers to gain valuable insights into the underlying causes of carcinogenesis and metastasis.

Inhibition of JNK/c-Jun-ATF2 Overcomes Cisplatin Resistance in Liver Cancer through down-Regulating Galectin-1

Due to drug resistance, the clinical response to cisplatin (CDDP) from patients with liver cancer is unsatisfactory. The alleviation or overcoming of CDDP resistance is an urgent problem to be solved in clinics. Tumor cells rapidly change signal pathways to mediate drug resistance under drug exposure. Here, multiple phosphor-kinase assays were performed and c-Jun N-terminal kinase (JNK) was activated in liver cancer cells treated with CDDP. The high activity of the JNK promotes poor progression and mediates cisplatin resistance in liver cancer, leading to a poor prognosis of liver cancer. Mechanistically, the highly activated JNK phosphorylated c-Jun and ATF2 formed a heterodimer to upregulate the expression of Galectin-1, leading to promoting cisplatin resistance in liver cancer. Importantly, we simulated the clinical evolution of drug resistance in liver cancer by continuous CDDP administration in vivo. In vivo bioluminescence imaging showed the activity of JNK gradually increased during this process. Moreover, the inhibition of JNK activity by small molecular or genetic inhibitors enhanced DNA damage and overcame CDDP resistance in vitro and in vivo. Collectively, our results underline that the high activity of JNK/c-Jun-ATF2/Galectin-1 mediates cisplatin resistance in liver cancer and provides an optional scheme for dynamic monitoring of molecular activity in vivo.

Inhibition of galectins in cancer: Biological challenges for their clinical application

Galectins play relevant roles in tumor development, progression and metastasis. Accordingly, galectins are certainly enticing targets for medical intervention in cancer. To date, however, clinical trials based on galectin inhibitors reported inconclusive results. This review summarizes the galectin inhibitors currently being evaluated and discusses some of the biological challenges that need to be addressed to improve these strategies for the benefit of cancer patients.

Pixantrone confers radiosensitization in KRAS mutated cancer cells by suppression of radiation-induced prosurvival pathways

Radioresistance towards radiation therapy has generated the need for the development of radiosensitizers as a potential drug. KRAS mutation brings radioresistance in tumor cells. The present work proves sensitization of cancer cells towards radiotherapy through inhibition of KRAS activation. Acquiring a drug repurposing approach, the in-silico screening revealed that pixantrone, an antineoplastic drug, possesses a high affinity towards KRAS G12C and G12D subtypes. The SPR study suggests that maximum affinity of pixantrone was observed with KRAS G12C>WT>G12D and G12S. Pixantrone potentially inhibited the KRAS activation in stable transfectants G12C and G12D cell lines and radiosensitized distinct KRAS mutant subtype cells. The combination of pixantrone with radiation causes enhanced dsDNA breaks along with enhanced ATM expression, and increased late apoptosis. The preclinical studies on NCr-fox1^nu xenograft mice showed potent inhibition of tumor progression and prolonged survival of mcie due to the radiosensitizing effect of pixantrone. Radiation-induced activation of key effector proteins of RAS downstream pathways, like MAPK and PI3K/Akt/mTOR pathways, were downregulated in tumor cells upon combination treatment. Interestingly, a robust upregulation of senescence marker p21 was observed in the tumor cells in combination treatment. These findings reveal a convergence between KRAS signaling, pixantrone treatment, and radiation conferring tumor cell death.

The multifaceted role of Matricellular Proteins in health and cancer, as biomarkers and therapeutic targets

The extracellular matrix (ECM) is composed of a mesh of proteins, proteoglycans, growth factors, and other secretory components. It constitutes the tumor microenvironment along with the endothelial cells, cancer-associated fibroblasts, adipocytes, and immune cells. The proteins of ECM can be functionally classified as adhesive proteins and matricellular proteins (MCP). In the tumor milieu, the ECM plays a major role in tumorigenesis and therapeutic resistance. The current review encompasses thrombospondins, osteonectin, osteopontin, tenascin C, periostin, the CCN family, laminin, biglycan, decorin, mimecan, and galectins. The matrix metalloproteinases (MMPs) are also discussed as they are an integral part of the ECM with versatile functions in the tumor stroma. In this review, the role of these proteins in tumor initiation, growth, invasion and metastasis have been highlighted, with emphasis on their contribution to tumor therapeutic resistance. Further, their potential as biomarkers and therapeutic targets based on existing evidence are discussed. Owing to the recent advancements in protein targeting, the possibility of agents to modulate MCPs in cancer as therapeutic options are discussed.

Prognostic Significance of Galectin-1 but Not Galectin-3 in Patients With Lung Adenocarcinoma After Radiation Therapy

Introduction

To investigate the role of tumor galectin-1 and galectin-3 in patients with lung adenocarcinoma after definitive radiation therapy.

Methods

A total of 41 patients with localized lung adenocarcinoma undergoing thoracic radiation therapy without concurrent chemotherapy were enrolled. Their paraffin-embedded lung tissues were sent for immunohistochemical staining for galectin-1 and galectin-3. The clinical treatment outcomes, including overall (OS), locoregional progression-free (LRPFS), and distant metastasis-free (DMFS) survivals, were evaluated. Univariable and multivariable Cox regression analyses were applied.

Results

Overexpression of tumor galectin-1 and galectin-3 were found in 26.8% and 19.5% of patients, respectively. Overexpression of tumor galectin-1 was the most significant prognosticator to predict worse LRPFS in both univariable (p = 0.007) and multivariable analyses (p = 0.022). Besides, patients with overexpression of tumor galectin-1 had a trend of worse OS (p = 0.066) than those with low expression in multivariable analysis, and worse DMFS (p = 0.035) in univariable analysis. The overexpression of tumor galectin-3 had no significant effect on survival outcomes.

Conclusions

The overexpression of tumor galectin-1, but not galectin-3, is associated with poor LRPFS of patients with lung adenocarcinoma after thoracic radiation therapy. Future research on the mechanism of galectin-1 affecting radiation response in lung adenocarcinoma may be worth exploring.

Glycosylation in Cervical Cancer: New Insights and Clinical Implications

Cervical cancer has become the most frequent female malignancy and presents as a general health challenge in many countries undergoing economic development. Various human papillomaviruses (HPV) types have appeared as one of the most critically identifiable causes of widespread cervical cancers. Conventional cervical cytological inspection has limitations of variable sensitivity according to cervical cytology. Glycobiology has been fundamental in related exploration in various gynecologic and reproductive fields and has contributed to our understanding of cervical cancer. It is associated with altered expression of N-linked glycan as well as abnormal expression of terminal glycan structures. The analytical approaches available to determine serum and tissue glycosylation, as well as potential underlying molecular mechanisms involved in the cellular glycosylation alterations, are monitored. Moreover, cellular glycosylation influences various aspects of cervical cancer biology, ranging from cell surface expressions, cell-cell adhesion, cancer signaling, cancer diagnosis, and management. In general, discoveries in glycan profiling make it technically reproducible and affordable to perform serum glycoproteomic analyses and build on previous work exploring an expanded variety of glycosylation markers in the majority of cervical cancer patients.

Galectin-1 Expression Is Associated with the Response and Survival Following Preoperative Chemoradiotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma

Simple Summary

Galectin-1 has been found to be involved in therapeutic resistance in a variety of cancers. However, the prognostic significance of galectin-1 expression in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated with chemoradiotherapy remains unknown. Immunohistochemically, we observed that galectin-1 overexpression in pretreatment biopsied specimens was significantly associated with a lower pathological complete response rate, worse overall survival and disease-free survival in 93 patients with locally advanced ESCC receiving preoperative chemoradiotherapy. Our findings suggest that galectin-1 may be a potential therapeutic target for patients with ESCC treated with preoperative chemoradiotherapy.

Abstract

The galectin-1 has been found to be involved in poor outcomes after treatment of a variety of cancers. To the best of our knowledge, however, the significance of galectin-1 expression in the sensitivity to chemoradiotherapy (CCRT) of patients with locally advanced esophageal squamous cell carcinoma (ESCC) remains unclear. Expression levels of galectin-1 were evaluated by immunohistochemistry and correlated with the treatment outcome in 93 patients with locally advanced ESCC who received preoperative CCRT between 1999 and 2012. Galectin-1 expression was significantly associated with the pathological complete response (pCR). The pCR rates were 36.1% and 13.0% (p = 0.01) in patients with low and high galectin-1 expression, respectively. Univariate analyses revealed that galectin-1 overexpression, clinical 7th American Joint Committee on Cancer (AJCC) stage III and a positive surgical margin were significant factors of worse overall survival and disease-free survival. In multivariate analyses, galectin-1 overexpression and a positive surgical margin represented the independent adverse prognosticators. Therefore, galectin-1 expression both affects the pCR and survival in patients with locally advanced ESCC receiving preoperative CCRT. Our results suggest that galectin-1 may be a potentially therapeutic target for patients with ESCC treated with preoperative CCRT.

Towards a Better Understanding of the Relationships between Galectin-7, p53 and MMP-9 during Cancer Progression

It has been almost 25 years since the discovery of galectin-7. This member of the galectin family has attracted interest from many working in the cancer field given its highly restricted expression profile in epithelial cells and the fact that cancers of epithelial origin (carcinoma) are among the most frequent and deadly cancer subtypes. Initially described as a p53-induced gene and associated with apoptosis, galectin-7 is now recognized as having a protumorigenic role in many cancer types. Several studies have indeed shown that galectin-7 is associated with aggressive behavior of cancer cells and induces expression of MMP-9, a member of the matrix metalloproteinases (MMP) family known to confer invasive behavior to cancer cells. It is therefore not surprising that many studies have examined its relationships with p53 and MMP-9. However, the relationships between galectin-7 and p53 and MMP-9 are not always clear. This is largely because p53 is often mutated in cancer cells and such mutations drastically change its functions and, consequently, its association with galectin-7. In this review, we discuss the functional relationships between galectin-7, p53 and MMP-9 and reconcile some apparently contradictory observations. A better understanding of these relationships will help to develop a working hypothesis and model that will provide the basis for further research in the hope of establishing a new paradigm for tackling the role of galectin-7 in cancer.

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.

Effects of Galectin-1 on Biological Behavior in Cervical Cancer

Background: We previously revealed that the expression of galectin-1 (LGALS1) was significantly reduced after neoadjuvant chemotherapy treatment in cervical cancer patients. The objective of this study is to investigate the effects of LGALS1 expression on biological behaviors of cervical cancer cells.

Methods: Immunohistochemistry and immunocytochemistry were performed to detect the expression of LGALS1 in cervical cancer tissues and cells (SiHa and C33A). Western blot analysis was performed to evaluate the efficacy of lentivirus-mediated upregulation or downregulation of LGALS1 in cervical cancer cells. Cell viability and proliferation were detected by CCK-8 and BrdU assays, respectively. Annexin V-FITC/PI apoptosis detection kit was employed to measure the apoptosis of cervical cancer cells. Transwell invasion and migration assays were also conducted to explore the invasive and migratory capabilities of cervical cancer cells. The expression of apoptosis- (Bcl-2 and Bax), invasion- (MMP-2 and MMP-9), and migration-related (Fascin and Ezrin) proteins, were detected by Western blot analysis. Xenograft mouse model of cervical cancer was generated to explore whether LGALS1 overexpression could promote tumor growth in vivo.

Results: LGALS1 was overexpressed in cervical cancer tissues and cell lines compared to that in normal cervical tissues and epithelium cells. Upregulation of LGALS1 significantly promoted the cell proliferation, inhibited cell apoptosis, and enhanced the migratory and invasive abilities of both SiHa and C33A cells, whereas downregulation of LGALS1 led to the opposite results. The level of Bcl-2, MMP-2, MMP-9, Fascin, and Erzin expression was significantly upregulated in cervical cancer cells with LGALS1 overexpression, while converse results were obtained in LGALS1 knockdown cancer cells. In vivo study also showed that LGALS1 overexpression facilitated tumor growth of cervical cancer cells.

Conclusion: Overexpression of LGALS1 significantly promoted and enhanced the aggressive features of cervical cancer both in vitro and in vivo, which may be associated with high expression of Bcl-2, MMP-2, MMP-9, Fascin, and Erzin proteins.

Aristolochic Acid Affects Upper Tract Urothelial Cancer Behavior through the MAPK Pathway

The prevalence of upper tract urothelial carcinoma (UTUC) in Taiwan is relatively higher than thatin Western countries. Aristolochic acid (AA), which is widely used in traditional Chinese herbology, is now recognized to be one of the carcinogens for UTUC. Numerous UTUC patients have chronic kidney diseases or end-stage renal diseases; however, little literature hasreported on theoncogenic pathway of AA-related UTUC. The aim of our study was to identify the potential target treatment for AA-related UTUC. Here, we established an AA pre-exposure followed bya 3-methylcholanthrene (MCA) stimulus tumorigenic cell model. We not only demonstrated that AA pre-exposure MCA stimulus tumorigenic cells have more behaviors of cell migration and invasion by enhancing the metalloproteinases (MMP) activity, which is compatible with clinical findings of AA-related UTUC, but we also validated that AA pre-exposure MCA stimulus tumorigeniccells could be activated through the mitogen-activated protein kinases (MAPK) pathway. We further dissected the route of the MAPK pathway and found that the p38 and extracellular signal regulated kinases (ERK) sub-pathways might play essential roles in AA pre-exposure urothelial cancer cell lines. This consequence was also corroborated with a tissue study in AA-exposed patients.

The Role of Galectins in Tumor Progression, Treatment and Prognosis of Gynecological Cancers

Galectins are the member of soluble proteins that bind with β-galactoside containing glycans. These proteins have been considered to be associated in various important events such as different types of cancers. It has been found that galectins could contribute to neoplastic transformation or regulate cell growth, cell apoptosis, and immune cells, causing tumor invasion, progression, metastasis and angiogenesis. Somehow, galectins are also found to exert a protective effect on cancer in a tissue-dependent way. These glycans binding proteins have been shown to be involved in the regulation of different tumor suppressor genes and oncogenes with their possible roles in human cancers. Objective of the current review is to summarize the role of galectin-1, -3 -7, and -9 in tumorigenesis of gynecological cancers. Galectin protein may be a potential therapeutic target in gynecological malignancies due to reported radio- and chemo- sensitivities, immunotherapeutic, anti-angiogenic and anti-proliferative activities. This review considers the evidence for the future research that how galectins may be important in the progression and treatment of gynecological cancers along with its potent use as a novel prognostic marker.

MIIP gene expression is associated with radiosensitivity in human nasopharyngeal carcinoma cells

The present study aims to investigate the radiosensitization effect of the migration and invasion inhibitory protein (MIIP) gene on nasopharyngeal carcinoma (NPC) cells. The MIIP gene was transfected into NPC 5-8F and CNE2 cells. The level of MIIP was analyzed by quantitative reverse transcription-polymerase chain reaction analysis and western blot. The changes in radiosensitivity of the cells were analyzed by colony formation assay. The changes in cell apoptosis and cycle distribution following irradiation were detected by flow cytometry. The expression of BCL2 associated X, apoptosis regulator/B-cell lymphoma 2 was evaluated using western blot. DNA damage was analyzed by counting γ-H2AX foci. The expression levels of γ-H2AX were evaluated by immunofluorescence and western blot. In a previous study by the authors, the results indicated that the expression of MIIP gene evidently increased in MIIP-transfected 5-8F (5-8F OE) and MIIP-transfected CNE2 (CNE2 OE) cells compared with the parental or negative control cells. In the present study, the survival rate of 5-8F OE and CNE2 OE cells markedly decreased following irradiation (0, 2, 4, 6 and 8 Gy) compared with the negative control (5-8F NC and CNE2 NC) and the untreated (5-8F and CNE2) groups. The expression of MIIP was able to increase apoptosis, which resulted in G2/M cell cycle arrest and DNA damage repair was attenuated in 5-8F and CNE2 cells following irradiation as measured by the accumulation of γ-H2AX. It was indicated that MIIP expression is associated with the radiosensitivity of NPC cells and has a significant role in regulating cell radiosensitivity.

The Role of Galectins in Cervical Cancer Biology and Progression

Cervical cancer is one of the malignant tumors with high incidence and high mortality among women in developing countries. The main factors affecting the prognosis of cervical cancer are the late recurrence and metastasis and the effective adjuvant treatment, which is radiation and chemotherapy or combination therapy. Galectins, a family containing many carbohydrate binding proteins, are closely involved in the occurrence and development of tumor. They are involved in tumor cells transformation, angiogenesis, metastasis, immune escape, and sensitivity against radiation and chemotherapy. Therefore, galectins are deemed as the targets of multifunctional cancer treatment. In this review, we mainly focus on the role of galectins, especially galectin-1, galectin-3, galectin-7, and galectin-9 in cervical cancer, and provide theoretical basis for potential targeted treatment of cervical cancer.

Distinct cargo-specific response landscapes underpin the complex and nuanced role of galectin-glycan interactions in clathrin-independent endocytosis

Clathrin-independent endocytosis (CIE) is a form of endocytosis that lacks a defined cytoplasmic machinery. Here, we asked whether glycan interactions, acting from the outside, could be a part of that endocytic machinery. We show that the perturbation of global cellular patterns of protein glycosylation by modulation of metabolic flux affects CIE. Interestingly, these changes in glycosylation had cargo-specific effects. For example, in HeLa cells, GlcNAc treatment, which increases glycan branching, increased major histocompatibility complex class I (MHCI) internalization but inhibited CIE of the glycoprotein CD59 molecule (CD59). The effects of knocking down the expression of galectin 3, a carbohydrate-binding protein and an important player in galectin-glycan interactions, were also cargo-specific and stimulated CD59 uptake. By contrast, inhibition of all galectin-glycan interactions by lactose inhibited CIE of both MHCI and CD59. None of these treatments affected clathrin-mediated endocytosis, implying that glycosylation changes specifically affect CIE. We also found that the galectin lattice tailors membrane fluidity and cell spreading. Furthermore, changes in membrane dynamics mediated by the galectin lattice affected macropinocytosis, an altered form of CIE, in HT1080 cells. Our results suggest that glycans play an important and nuanced role in CIE, with each cargo being affected uniquely by alterations in galectin and glycan profiles and their interactions. We conclude that galectin-driven effects exist on a continuum from stimulatory to inhibitory, with distinct CIE cargo proteins having unique response landscapes and with different cell types starting at different positions on these conceptual landscapes.

Galectins as Molecular Targets for Therapeutic Intervention

Galectins are a family of small, highly conserved, molecular effectors that mediate various biological processes, including chemotaxis and angiogenesis, and that function by interacting with various cell surface glycoconjugates, usually targeting β-galactoside epitopes. Because of their significant involvement in various biological functions and pathologies, galectins have become a focus of therapeutic discovery for clinical intervention against cancer, among other pathological disorders. In this review, we focus on understanding galectin structure-function relationships, their mechanisms of action on the molecular level, and targeting them for therapeutic intervention against cancer.

Effects of radiation response modifiers given after lethal whole-abdominal irradiation

PURPOSE

Although radiation is used to treat cancer and generate electricity, radiotherapy-induced complications and nuclear disasters are issues of great concern. The small bowel and bone marrow are the two major organs injured by radiation, especially that from nuclear disasters. The development of effective drugs to alleviate radiation injuries is very important. We tested potential radiation response modifiers given after irradiation to alleviate radiation injuries and mortality.

MATERIALS AND METHODS

Xenografts of C33A tumor cells with or without galectin-1 expression were implanted in SCID mice. Local tumor irradiation (6 Gy) was used to study radiosensitivity. The rate and time of tumor growth to 2 cm were observed using the Kaplan-Meier method. C57BL/6N mice were used to study the effects of whole-abdominal or whole-body irradiation. Drug administration was as follows: (1) vehicle; (2) interleukin 6 (IL-6) (50 ng/day); (3) anginex (10 mg/kg/day) (galectin-1 antagonist); or (4) flagellin (0.2 mg/kg) (Toll-like receptor 5 agonist). These treatments were compared for tumor size and survival time.

RESULTS

The median time of tumor growth delay after 6 Gy irradiation was one week in tumors without galectin-1 expression, regardless of anginex administration. Anginex did not prolong the survival time after 18 Gy whole-abdominal irradiation. Flagellin did not prolong survival time after 18 Gy whole-abdominal irradiation. IL-6 prolonged the survival time after 18 Gy whole-abdominal irradiation, with 5% survival. This was the best result in treating lethal 18 Gy whole-abdominal irradiation. Other than IL-6, no drugs decreased the survival rate after 7.5 Gy whole-body irradiation.

CONCLUSIONS

Anginex has no protective effects against radiation injury and no radiosensitized effects on tumors. IL-6 is a potential agent for treating radiation-induced lethal injuries to the small bowel. However, it is not suitable for treating bone marrow damage after whole-body irradiation.

Galectin-1 is a poor prognostic factor in patients with glioblastoma multiforme after radiotherapy

Background

Galectin-1, a radioresistance marker, was found in our previous study to be a prognostic factor for cervical cancer. The aim of current study is to determine the prognostic significance of the galectin-1 expression level in patients with glioblastoma multiforme (GBM) undergoing adjuvant radiotherapy (RT).

Methods

We included 45 patients with GBM who were treated with maximal safe surgical resection or biopsy alone followed by adjuvant RT of EQD2 (equivalent dose in 2-Gy fractions) > or = 60 Gy for homogeneous treatment. Paraffin-embedded tissues acquired from the Department of Pathology were analyzed using immunohistochemical staining for galectin-1 expression. The primary endpoint was overall survival (OS).

Results

Patients with weak expression had a better median survival (27.9 months) than did those with strong expression (10.7 months; p = 0.009). We compared characteristics between weak and strong galectin-1 expression, and only the expression level of galectin-3 showed a correlation. The group with weak galectin-1 expression displayed a 3-year OS of 27.3% and a 3-year cancer-specific survival (CSS) of 27.3%; these values were only 5.9% and 7.6%, respectively, in the group with strong galectin-1 expression (p = 0.009 and 0.020, respectively). Cox regression was used to confirm that the expression level of galectin-1 (weak vs. strong) is a significant factor of OS (p = 0.020) and CSS (p = 0.022). Other parameters, such as the expression level of galectin-3, Eastern Cooperative Oncology Group (ECOG) performance, gender, surgical method, age ≥ 50 years, tumor size, or radiation field were not significant factors.

Conclusion

The expression level of galectin-1 affects survival in patients with GBM treated with adjuvant RT. Future studies are required to analyze the effect of other factors, such as O(6)-methylguanine-DNA methyltransferase (MGMT)-promoter methylation status, in patients with weak and strong galectin-1 expression.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4025-2) contains supplementary material, which is available to authorized users.

Cancer stem cells and signaling pathways in radioresistance

Radiation therapy (RT) is one of the most important strategies in cancer treatment. Radioresistance (the failure to RT) results in locoregional recurrence and metastasis. Therefore, it is critically important to investigate the mechanisms leading to cancer radioresistance to overcome this problem and increase patients' survival. Currently, the majority of the radioresistance-associated researches have focused on preclinical studies. Although the exact mechanisms of cancer radioresistance have not been fully uncovered, accumulating evidence supports that cancer stem cells (CSCs) and different signaling pathways play important roles in regulating radiation response and radioresistance. Therefore, targeting CSCs or signaling pathway proteins may hold promise for developing novel combination modalities and overcoming radioresistance. The present review focuses on the key evidence of CSC markers and several important signaling pathways in cancer radioresistance and explores innovative approaches for future radiation treatment.

Photobiomodulation leads to enhanced radiosensitivity through induction of apoptosis and autophagy in human cervical cancer cells

The radiomodulatory effect of photobiomodulation (PBM) has recently been studied in cancer cells. The aim of this study was to investigate cellular mechanisms involved in the X-ray radiosensitivity of HeLa cells pre-exposed to PBM. HeLa cells were irradiated with 685 nm laser at different energy densities prior to X-ray ionizing radiation. After irradiation, clonogenic cell survival, cell death due to apoptosis and autophagy were determined. Levels of intracellular reactive oxygen species (ROS), DNA damage and, cell cycle distribution after PBM were measured. PBM at different energy densities (5-20 J/cm² ) was not cytotoxic. However, HeLa cells pre-exposed to 20 J/cm² showed enhanced inhibition of colony formation following ionizing radiation. Enhanced radiosensitivity was due to increased oxidative stress, DNA damage, and radiation-induced apoptosis and autophagy. These results suggest that 685 nm PBM at a higher energy density could possibly be a promising radiosensitizing agent in cervical cancer, to decrease the radiation dose delivered, and therefore prevent the side-effects that are associated with cancer radiotherapy.

Olaparib modulates DNA repair efficiency, sensitizes cervical cancer cells to cisplatin and exhibits anti-metastatic property

PARP1 trapping at DNA lesion by pharmacological inhibitors has been exploited in several cancers exhibiting defects in DNA repair mechanisms. PARP1 hyperactivation is involved in therapeutic resistance in multiple cancers. The role of PARP1 in cervical cancer (CC) resistance and implication of PARP inhibitor is yet to be elucidated. Our data demonstrates significantly higher expression of PARP1 in primary cervical tumors and CC cell lines SiHa and ME180. Upon cisplatin treatment CC cells display significant overexpression of PARP1 and its hyperactivation. PARP inhibitor olaparib shows significant anti-proliferative effect on CC cells and drive loss of clonogenic survival and enhanced cell death in combination with cisplatin. PARP inhibited cells show delay in resolution of γH2A.X foci and prolonged late S and G2-M phase arrest resulting in apoptosis. Further, PARP inhibition disrupts the localization of base excision repair (BER) effector XRCC1 and non-homologous end joining (NHEJ) proteins Ku80 and XRCC4. Due to disrupted relocation of repair factors, cisplatin induced stalled replication forks collapse and convert into double strand breaks (DSBs). Interestingly, PARP inhibition also shows anti-migratory and anti-invasive properties in CC cells, increases anchorage independent cell death and induces anoikis. Collectively, our data demonstrates therapeutic potential of PARP inhibitor in cervical cancer.

The involvement of E6, p53, p16, MDM2 and Gal-3 in the clinical outcome of patients with cervical cancer

High-risk human papilloma virus (HPV) is the leading cause of cervical cancer. HPV oncogenes are responsible for the development of malignancy, and the E6 oncoprotein that HPV expresses induces the degradation of tumour suppressor protein p53 (p53). This degradation leads to the upregulation of p16; however, unidentified proteins may also serve a role in the development and progression of cervical cancer. Therefore, the aim of the present study was to analyse the expression levels of E6, p53, p16, MDM2 proto-oncogene (MDM2) and galectin-3 (gal-3) in cervical cancer specimens. A total of 250 cervical cancer tissue slides were used. The expression of E6, p53, p16, MDM2 and gal-3 was analysed with immunohistochemical methods and a semi-quantitative scoring. SPSS software was used for the statistical evaluation of staining results and survival analysis of patients with cervical cancer. Cervical cancer specimens demonstrated significantly increased E6 staining with advanced T-status and increased International Federation of Gynecology and Obstetrics classification. E6, p53 and p16 demonstrated significantly different expression levels in squamous epithelial tissue compared with adenocarcinomas. MDM2 and gal-3 demonstrated positively correlated expression levels in cervical cancer. In addition, gal-3 expression was correlated with poor prognosis in p16-negative cases. A negative correlation between the expression of E6 and a mutated form of p53 was also identified in cervical cancer. p53 mutation was demonstrated to be common in cervical cancer, and gal-3 and MDM2 appeared to act in a combined manner in this type of tumour. As gal-3 is overexpressed in the cervical cancer tissue of patients with poor prognosis, the use of gal-3 inhibitors should be investigated in future studies.

Downregulation of a novel human gene, ROGDI, increases radiosensitivity in cervical cancer cells

ROGDI is a protein that contains a leucine zipper domain and may be involved in cell proliferation. In addition, ROGDI is associated with genome stability by regulating the activity of a DNA damage marker, γ-H2AX. The role of ROGDI in tumor radiosensitization has not been investigated. Previous studies have indicated that radiosensitivity is associated with DNA repair and the cell cycle. In general, the G2/M DNA damage checkpoint is more sensitive to radiation, whereas the G1/S phase transition is more resistant to radiation. Inhibition of cyclin-dependent kinases (CDKs) can lead to a halt of cell cycle progression and a stay at different phases or checkpoints. Our data show that the downregulation of ROGDI led to a decreased expression of CDK 1, 2, cyclin A, B and resulted in a G2/M phase transition block. In addition, the downregulation of ROGDI increased cell accumulation at the G2 phase as detected using flow cytometry and decreased cell survival as revealed by clonogenic assay in HeLa and C33A cells following irradiation. These findings suggest that the downregulation of ROGDI can mediate radiosensitivity by blocking cells at G2/M, the most radiosensitive phase of the cell cycle, as well as exerting deleterious effects in the form of DNA damage, as shown by increased γ-H2AX activation.

Systems-level effects of ectopic galectin-7 reconstitution in cervical cancer and its microenvironment

Background

Galectin-7 (Gal-7) is negatively regulated in cervical cancer, and appears to be a link between the apoptotic response triggered by cancer and the anti-tumoral activity of the immune system. Our understanding of how cervical cancer cells and their molecular networks adapt in response to the expression of Gal-7 remains limited.

Methods

Meta-analysis of Gal-7 expression was conducted in three cervical cancer cohort studies and TCGA. In silico prediction and bisulfite sequencing were performed to inquire epigenetic alterations. To study the effect of Gal-7 on cervical cancer, we ectopically re-expressed it in the HeLa and SiHa cervical cancer cell lines, and analyzed their transcriptome and SILAC-based proteome. We also examined the tumor and microenvironment host cell transcriptomes after xenotransplantation into immunocompromised mice. Differences between samples were assessed with the Kruskall-Wallis, Dunn’s Multiple Comparison and T tests. Kaplan–Meier and log-rank tests were used to determine overall survival.

Results

Gal-7 was constantly downregulated in our meta-analysis (p < 0.0001). Tumors with combined high Gal-7 and low galectin-1 expression (p = 0.0001) presented significantly better prognoses (p = 0.005). In silico and bisulfite sequencing assays showed de novo methylation in the Gal-7 promoter and first intron. Cells re-expressing Gal-7 showed a high apoptosis ratio (p < 0.05) and their xenografts displayed strong growth retardation (p < 0.001). Multiple gene modules and transcriptional regulators were modulated in response to Gal-7 reconstitution, both in cervical cancer cells and their microenvironments (FDR < 0.05 %). Most of these genes and modules were associated with tissue morphogenesis, metabolism, transport, chemokine activity, and immune response. These functional modules could exert the same effects in vitro and in vivo, even despite different compositions between HeLa and SiHa samples.

Conclusions

Gal-7 re-expression affects the regulation of molecular networks in cervical cancer that are involved in diverse cancer hallmarks, such as metabolism, growth control, invasion and evasion of apoptosis. The effect of Gal-7 extends to the microenvironment, where networks involved in its configuration and in immune surveillance are particularly affected.

Electronic supplementary material

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Galectin-1 dimers can scaffold Raf-effectors to increase H-ras nanoclustering

Galectin-1 (Gal-1) dimers crosslink carbohydrates on cell surface receptors. Carbohydrate-derived inhibitors have been developed for cancer treatment. Intracellularly, Gal-1 was suggested to interact with the farnesylated C-terminus of Ras thus specifically stabilizing GTP-H-ras nanoscale signalling hubs in the membrane, termed nanoclusters. The latter activity may present an alternative mechanism for how overexpressed Gal-1 stimulates tumourigenesis. Here we revise the current model for the interaction of Gal-1 with H-ras. We show that it indirectly forms a complex with GTP-H-ras via a high-affinity interaction with the Ras binding domain (RBD) of Ras effectors. A computationally generated model of the Gal-1/C-Raf-RBD complex is validated by mutational analysis. Both cellular FRET as well as proximity ligation assay experiments confirm interaction of Gal-1 with Raf proteins in mammalian cells. Consistently, interference with H-rasG12V-effector interactions basically abolishes H-ras nanoclustering. In addition, an intact dimer interface of Gal-1 is required for it to positively regulate H-rasG12V nanoclustering, but negatively K-rasG12V nanoclustering. Our findings suggest stacked dimers of H-ras, Raf and Gal-1 as building blocks of GTP-H-ras-nanocluster at high Gal-1 levels. Based on our results the Gal-1/effector interface represents a potential drug target site in diseases with aberrant Ras signalling.

Inhibition of Glut1 by WZB117 sensitizes radioresistant breast cancer cells to irradiation

PURPOSE

Breast cancer is the most common type of cancer with high incidence in women. Currently, identifying new therapies that selectively inhibit tumor growth without damaging normal tissue are a major challenge of cancer research. One of the features of cancer cells is that they do not consume more oxygen even under normal oxygen circumstances but prefer to aerobic glycolysis through the enhanced catabolism of glucose and glutamine. In this study, we investigate the mechanisms of the radioresistance in breast cancer cells.

METHODS

Human breast cancer cells MDA-MB-231 and MCF-7 were treated with radiation alone, Glut1 inhibitor alone or the combination of both to evaluate cell glucose metabolism and apoptosis. By the establishment of radioresistant cell line, we investigate the mechanisms of the combined treatments of radiation with Glut1 inhibitor in the radioresistant cells.

RESULTS

The glucose metabolism and the expression of Glut1 are significantly stimulated by radiotherapy. We report the radioresistant breast cancer cells exhibit upregulated Glut1 expression and glucose metabolism. In addition, we observed overexpression of Glut1 renders breast cancer cells resistant to radiation and knocking down of Glut1 sensitizes breast cancer cells to radiation. We treated breast cancer cells with radiation and WZB117 which inhibits Glut1 expression and glucose metabolism and found the combination of WZB117 and radiation exhibits synergistically inhibitory effects on breast cancer cells. Finally, we demonstrate the inhibition of Glut1 re-sensitizes the radioresistant cancer cells to radiation.

CONCLUSIONS

This study reveals the roles of Glut1 in the radiosensitivity of human breast cancer. It will provide new mechanisms and strategies for the sensitization of cancer cells to radiotherapy through regulation of glucose metabolism.

Multidrug Resistance-associated Protein-1 (MRP-1)-dependent Glutathione Disulfide (GSSG) Efflux as a Critical Survival Factor for Oxidant-enriched Tumorigenic Endothelial Cells

Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics.

The relevance of molecular biomarkers in cervical cancer patients treated with radiotherapy

BACKGROUND

Radiotherapy (RT) plays an integral role in the combined-modality management of cervical cancer. Various molecular mechanisms have been implicated in the adaptive cellular response to RT. Identification of these molecular processes may permit the prediction of treatment outcome and enhanced radiation-induced cancer cell killing through tailoring of the management approach, and/or the employment of selective inhibitors of these pathways.

METHODS

PubMed was searched for studies presenting biomarkers of cervical cancer radioresistance validated in patient studies or in laboratory experimentation.

RESULTS

Several biomarkers of cervical cancer radioresistance are validated by patient survival or recurrence data. These biomarkers fall into categories of biological function including hypoxia, cell proliferation, cell-cell adhesion, and evasion of apoptosis. Additional radioresistance biomarkers have been identified in exploratory experiments.

CONCLUSIONS

Biomarkers of radioresistance in cervical cancer may allow molecular profiling of individual tumors, leading to tailored therapies and better prognostication and prediction of outcomes.

Lysophosphatidic Acid Inhibits Apoptosis Induced by Cisplatin in Cervical Cancer Cells

Cervical cancer is the second most common cause of cancer death in women worldwide. Lysophosphatidic acid (LPA) level has been found significantly increased in the serum of patients with ovarian, cervical, and colon cancers. LPA level in cervical cancer patients is significantly higher than in healthy controls. LPA receptors were found highly expressed in cervical cancer cells, suggesting LPA may play a role in the development of cervical cancer. The aim of this study is to investigate the effect of LPA on the apoptosis induced by cisplatin (DDP) in cervical cancer cell line and the underlying changes in signaling pathways. Our study found that cisplatin induced apoptosis of Hela cell through inhibiting expression of Bcl-2, upregulating the expression of Bax, Fas-L, and the enzyme activity of caspase-3 (p < 0.05); LPA significantly provided protection against the apoptosis induced by cisplatin by inhibiting the above alterations in apoptotic factor caused by cisplatin (p < 0.05). Moreover, PI3K/AKT pathway was found to be important for the LPA antiapoptosis effect, and administration of PI3K/AKT partially reversed the LPA-mediated protection against cisplatin-induced apoptosis (p < 0.05). These findings have shed new lights on the LPA bioactivity in cervical cancer cells and pointed to a possible sensitization scheme through combined administration of PI3K inhibitor and cisplatin for better treatment of cervical cancer patients, especially those with elevated LPA levels.

Amifostine alleviates radiation-induced lethal small bowel damage via promotion of 14-3-3σ-mediated nuclear p53 accumulation

Amifostine (AM) is a radioprotector that scavenges free radicals and is used in patients undergoing radiotherapy. p53 has long been implicated in cell cycle arrest for cellular repair after radiation exposure. We therefore investigated the protective p53-dependent mechanism of AM on small bowel damage after lethal whole-abdominal irradiation (WAI). AM increased both the survival rate of rats and crypt survival following lethal 18 Gy WAI. The p53 inhibitor PFT-α compromised AM-mediated effects when administered prior to AM administration. AM significantly increased clonogenic survival in IEC-6 cells expressing wild type p53 but not in p53 knockdown cells. AM significantly increased p53 nuclear accumulation and p53 tetramer expression before irradiation through the inhibition of p53 degradation. AM inhibited p53 interactions with MDM2 but enhanced p53 interactions with 14-3-3σ. Knockdown of 14-3-3σ also compromised the effect of AM on clonogenic survival and p53 nuclear accumulation in IEC-6 cells. For the first time, our data reveal that AM alleviates lethal small bowel damage through the induction of 14-3-3σ and subsequent accumulation of p53. Enhancement of the p53/14-3-3σ interaction results in p53 tetramerization in the nucleus that rescues lethal small bowel damage.

Galectins: Double-edged Swords in the Cross-roads of Pregnancy Complications and Female Reproductive Tract Inflammation and Neoplasia

Galectins are an evolutionarily ancient and widely expressed family of lectins that have unique glycan-binding characteristics. They are pleiotropic regulators of key biological processes, such as cell growth, proliferation, differentiation, apoptosis, signal transduction, and pre-mRNA splicing, as well as homo- and heterotypic cell-cell and cell-extracellular matrix interactions. Galectins are also pivotal in immune responses since they regulate host-pathogen interactions, innate and adaptive immune responses, acute and chronic inflammation, and immune tolerance. Some galectins are also central to the regulation of angiogenesis, cell migration and invasion. Expression and functional data provide convincing evidence that, due to these functions, galectins play key roles in shared and unique pathways of normal embryonic and placental development as well as oncodevelopmental processes in tumorigenesis. Therefore, galectins may sometimes act as double-edged swords since they have beneficial but also harmful effects for the organism. Recent advances facilitate the use of galectins as biomarkers in obstetrical syndromes and in various malignancies, and their therapeutic applications are also under investigation. This review provides a general overview of galectins and a focused review of this lectin subfamily in the context of inflammation, infection and tumors of the female reproductive tract as well as in normal pregnancies and those complicated by the great obstetrical syndromes.

HAP1 gene expression is associated with radiosensitivity in breast cancer cells

OBJECTIVES

The purpose of this study was to investigate the relationship between huntingtin-associated protein1 (HAP1) gene and radiation therapy of breast cancer cells.

METHODS

HAP1 gene was transfected into breast cancer MCF-7 cells, which was confirmed by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) and Western blot in vitro. The changes of cell radiosensitivity were assessed by colony formation assay. Apoptosis were examined by flow cytometry. The expressions of two radiation-induced genes were evaluated by Western blot. Tumor growth was investigated in nude mice xenograft models in vivo.

RESULTS

Our data showed that HAP1 gene expression was significantly increased in HAP1-transfected MCF-7 cells in comparison with the parental cells or negative control cells. The survival rate in MCF-7/HAP1 cells was significantly decreased after irradiation (0, 2, 4, 6, 8Gy), compared to cells in MCF-7 and MCF-7/Pb groups in vitro. HAP1 gene increased apoptosis in MCF-7 cells after irradiation. Additionally, the tumor volume and weight in MCF-7/HAP1+RT group were observably lower than in MCF-7/HAP1 group and MCF-7/Pb+RT group.

CONCLUSION

The present study indicated that HAP1 gene expression was related to the radiosensitivity of breast cancer cells and may play an important role in the regulation of cellular radiosensitivity.

Galectins in cancer: carcinogenesis, diagnosis and therapy

A major breakthrough in the field of medical oncology has been the discovery of galectins and their role in cancer development, progression and metastasis. In this review article we have condensed the results of a number of studies published over the past decade in an effort to shed some light on the unique role played by the galectin family of proteins in neoplasia, and how this knowledge may alter the approach to cancer diagnosis as well as therapy in the future. In this review we have also emphasized the potential use of galectin inhibitors or modulators in the treatment of cancer and how this novel treatment modality may affect patient outcomes in the future. Based on current pre-clinical models we believe the use of galectin inhibitors/modulators will play a significant role in cancer treatment in the future. Early clinical studies are underway to evaluate the utility of these promising agents in cancer patients.

Galectin-1 mediates radiation-related lymphopenia and attenuates NSCLC radiation response

PURPOSE

Radiotherapy can result in lymphopenia, which has been linked to poorer survival. Here, we test the hypothesis that radiotherapy-induced lymphopenia is mediated by a tumor-secreted factor, Galectin-1 (Gal-1), which possesses T-cell proapoptotic activities.

EXPERIMENTAL DESIGN

Matched Gal-1 wild-type (WT) or null mice were implanted with Lewis lung carcinoma (LLC-1) that either expressed Gal-1 or had Gal-1 stably downregulated. Tumors were irradiated locally and circulating Gal-1 and T cells were measured. Tumor growth, lung metastasis, intratumoral T-cell apoptosis, and microvessel density count were quantified. Thiodigalactoside (TDG), a Gal-1 inhibitor, was used to inhibit Gal-1 function in another group of mice to validate the observations noted with Gal-1 downregulation. Lymphocyte counts, survival, and plasma Gal-1 were analyzed in cohorts of radiotherapy-treated lung [non-small cell lung cancer (NSCLC)] and head and neck cancer patients.

RESULTS

LLC irradiation increased Gal-1 secretion and decreased circulating T cells in mice, regardless of host Gal-1 expression. Inhibition of tumor Gal-1 with either shRNA or thiodigalactoside ablated radiotherapy-induced lymphopenia. Irradiated shGal-1 tumors showed significantly less intratumoral CD8(+) T-cell apoptosis and microvessel density, which led to marked tumor growth delay and reduced lung metastasis compared with controls. Similar observations were made after thiodigalactoside treatment. Radiotherapy-induced lymphopenia was associated with poorer overall survival in patients with NSCLC treated with hypofractionated radiotherapy. Plasma Gal-1 increased whereas T-cell decreased after radiation in another group of patients.

CONCLUSIONS

Radiotherapy-related systemic lymphopenia appeared to be mediated by radiotherapy-induced tumor Gal-1 secretion that could lead to tumor progression through intratumoral immune suppression and enhanced angiogenesis.

Galectins in cancer: carcinogenesis, diagnosis and therapy

A major breakthrough in the field of medical oncology has been the discovery of galectins and their role in cancer development, progression and metastasis. In this review article we have condensed the results of a number of studies published over the past decade in an effort to shed some light on the unique role played by the galectin family of proteins in neoplasia, and how this knowledge may alter the approach to cancer diagnosis as well as therapy in the future. In this review we have also emphasized the potential use of galectin inhibitors or modulators in the treatment of cancer and how this novel treatment modality may affect patient outcomes in the future. Based on current pre-clinical models we believe the use of galectin inhibitors/modulators will play a significant role in cancer treatment in the future. Early clinical studies are underway to evaluate the utility of these promising agents in cancer patients.

Galectin-1 links tumor hypoxia and radiotherapy

Radiation therapy is a main stay in treating solid tumors and plays a significant role in definitive and adjuvant therapy. Unfortunately, local control remains a challenge, in which the success of radiotherapy is largely dictated by tumor hypoxia, DNA damage repair and the antitumor immune response. Extensive efforts have therefore been devoted to targeting the factors that attenuate tumor radiosensitivity, although with limited success. Mounting evidence suggests that tumor and endothelial cells may utilize galectin-1 (Gal-1) for protection against radiation through several mechanisms. Targeting Gal-1 in combination with radiotherapy provides an exciting approach to address several radiation-prohibitive mechanisms.

Galectin-1 upregulates CXCR4 to promote tumor progression and poor outcome in kidney cancer

Galectin-1, a β-galactoside-binding lectin, is involved in many physiologic and pathologic processes, including cell adhesion, differentiation, angiogenesis, and tumor progression. However, the role of galectin-1 in kidney cancer remains elusive. This study evaluated the role of galectin-1 in the progression and clinical prognosis of renal cell carcinoma. We found significant overexpression of galectin-1 in both kidney cancer cell lines and metastatic tissue specimens from patients with renal cell carcinoma. Knockdown of galectin-1 gene expression in renal cancer cell lines reduced cell invasion, clonogenic ability, and epithelial-mesenchymal transition in vitro; reduced tumor outgrowth in vivo; and inhibited the angiogenesis-inducing activity of these cells in vitro and in vivo. Galectin-1 knockdown decreased CXCR4 expression levels in kidney cancer cells, and restoration of CXCR4 expression in galectin-1-silenced cells rescued cell motility and clonogenic ability. Additional studies suggested that galectin-1 induced CXCR4 expression through activation of nuclear factor-κB (NF-κB). Analysis of patient specimens confirmed the clinical significance and positive correlation between galectin-1 and CXCR4 expression levels and revealed concomitant overexpression of galectin-1 and CXCR4 associated adversely with overall and disease-free survival. Our findings suggest that galectin-1 promotes tumor progression through upregulation of CXCR4 via NF-κB. The coordinated upregulation of galectin-1 and CXCR4 may be a novel prognostic factor for survival in patients with renal cell carcinoma and the galectin-1-CXCR4 axis may serve as a therapeutic target in this disease.

Myosin IIa activation is crucial in breast cancer derived galectin-1 mediated tolerogenic dendritic cell differentiation

BACKGROUND

Tolerogenic dendritic cells (tDCs) play important roles in immune tolerance, autoimmune disease, tissue transplantation, and the tumor micro-environment. Factors that induce tDCs have been reported, however the intracellular mechanisms involved are rarely discussed.

METHODS

Circulating CD14(+)CD16(+) of breast cancer patients and induced CD14(+)CD16(+) DCs were identified as tDCs by treating CD14(+) monocytes with galectin-1 and cancer cell-derived medium combined with IL-4 and GM-CSF. In addition, the 4T1 breast cancer syngeneic xenograft model was used to investigate the effect of galectin-1 in vivo.

RESULTS

The CD14(+)CD16(+) tDC population in the breast cancer patients was comparatively higher than that in the healthy donors, and both the MDA-MB-231 conditioned medium and galectin-1 could induce tDC differentiation. In a BALB/c animal model, the 4T1 breast cancer cell line enhanced IL-10 expression in CD11c(+) DCs which was down-regulated after knocking down the galectin-1 expression of 4T1 cells. Analysis of galectin-1 interacting proteins showed that myosin IIa was a major target of galectin-1 after internalization through a caveolin-dependent endocytosis. Myosin IIa specific inhibitor could diminish the effects of galectin-1 on monocyte-derived tDCs and also block the 4T1 cell induced CD11c(+)/Ly6G(+)/IL-10(+) in the BALB/c mice.

CONCLUSIONS

Galectin-1 can induce tDCs after internalizing into CD14(+) monocytes through the caveolae-dependent pathway and activating myosin IIa. For the breast cancer patients with a high galectin-1 expression, blebbistatin and genistein show potential in immune modulation and cancer immunotherapy.

GENERAL SIGNIFICANCE

Myosin IIa activation and galectin-1 endocytosis are important in tumor associated tDC development.

Intracellular galectins in cancer cells: potential new targets for therapy (Review)

Dysregulation of galectin expression is frequently observed in cancer tissues. Such an abnormal expression pattern often correlates with aggressiveness and relapse in many types of cancer. Because galectins have the ability to modulate functions that are important for cell survival, migration and metastasis, they also represent attractive targets for cancer therapy. This has been well-exploited for extracellular galectins, which bind glycoconjugates expressed on the surface of cancer cells. Although the existence of intracellular functions of galectins has been known for many years, an increasing number of studies indicate that these proteins can also alter tumor progression through their interaction with intracellular ligands. In fact, in some instances, the interactions of galectins with their intracellular ligands seem to occur independently of their carbohydrate recognition domain. Such findings call for a change in the basic assumptions, or paradigms, concerning the activity of galectins in cancer and may force us to revisit our strategies to develop galectin antagonists for the treatment of cancer.

Galectin-1 overexpression promotes progression and chemoresistance to cisplatin in epithelial ovarian cancer

This study was performed to investigate the role of galectin-1 (Gal-1) in epithelial ovarian cancer (EOC) progression and chemoresistance. Tissue samples from patients with EOC were used to examine the correlation between Gal-1 expression and clinical stage of EOC. The role of Gal-1 in EOC progression and chemoresistance was evaluated in vitro by siRNA-mediated knockdown of Gal-1 or lentivirus-mediated overexpression of Gal-1 in EOC cell lines. To elucidate the molecular mechanisms underlying Gal-1-mediated tumor progression and chemoresistance, the expression and activities of some signaling molecules associated with Gal-1 were analyzed. We found overexpression of Gal-1 in advanced stages of EOC. Knockdown of endogenous Gal-1 in EOC cells resulted in the reduction in cell growth, migration, and invasion in vitro, which may be caused by Gal-1's interaction with H-Ras and activation of the Raf/extracellular signal-regulated kinase (ERK) pathway. Additionally, matrix metalloproteinase-9 (MMP-9) and c-Jun were downregulated in Gal-1-knockdown cells. Notably, Gal-1 overexpression could significantly decrease the sensitivities of EOC cells to cisplatin, which might be ascribed to Gal-1-induced activation of the H-Ras/Raf/ERK pathway and upregulation of p21 and Bcl-2. Taken together, the results suggest that Gal-1 contributes to both tumorigenesis and cisplatin resistance in EOC. Thus, Gal-1 is a potential therapeutic target for EOC.

Unraveling galectin-1 as a novel therapeutic target for cancer

Galectins belong to a family of carbohydrate-binding proteins with an affinity for β-galactosides. Galectin-1 is differentially expressed by various normal and pathologic tissues and displays a wide range of biological activities. In oncology, galectin-1 plays a pivotal role in tumor growth and in the multistep process of invasion, angiogenesis, and metastasis. Evidence indicates that galectin-1 exerts a variety of functions at different steps of tumor progression. Moreover, it has been demonstrated that galectin-1 cellular localization and galectin-1 binding partners depend on tumor localization and stage. Recently, galectin-1 overexpression has been extensively documented in several tumor types and/or in the stroma of cancer cells. Its expression is thought to reflect tumor aggressiveness in several tumor types. Galectin-1 has been identified as a promising drug target using synthetic and natural inhibitors. Preclinical data suggest that galectin-1 inhibition may lead to direct antiproliferative effects in cancer cells as well as antiangiogenic effects in tumors. We provide an up-to-date overview of available data on the role of galectin-1 in different molecular and biochemical pathways involved in human malignancies. One of the major challenges faced in targeting galectin-1 is the translation of current knowledge into the design and development of effective galectin-1 inhibitors in cancer therapy.

Galectin-1 as a potent target for cancer therapy: role in the tumor microenvironment

The microenvironment of a tumor is a highly complex milieu, primarily characterized by immunosuppression, abnormal angiogenesis, and hypoxic regions. These features promote tumor progression and metastasis, resulting in poor prognosis and greater resistance to existing cancer therapies. Galectin-1 is a β-galactoside binding protein that is abundantly secreted by almost all types of malignant tumor cells. The expression of galectin-1 is regulated by hypoxia-inducible factor-1 (HIF-1) and it plays vital pro-tumorigenic roles within the tumor microenvironment. In particular, galectin-1 suppresses T cell-mediated cytotoxic immune responses and promotes tumor angiogenesis. However, since galectin-1 displays many different activities by binding to a number of diverse N- or O-glycan modified target proteins, it has been difficult to fully understand how galectin-1 supports tumor growth and metastasis. This review explores the importance of galectin-1 and glycan expression patterns in the tumor microenvironment and the potential effects of inhibiting galectin-1 as a therapeutic target for cancer treatment.

Proteomic identification of neoadjuvant chemotherapy-related proteins in bulky stage IB-IIA squamous cervical cancer

OBJECTIVE

The aim of this study was to investigate the effect of neoadjuvant chemotherapy (NAC) on the human squamous cervical cancer using proteomics profiling and to obtain related proteins to NAC exposure and response.

METHODS

Paired samples of early-stage bulky squamous cervical cancer before and after NAC treatment from patients who responded to NAC were obtained and submitted to 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS). The expression and localization of the interesting proteins in additional paired samples were confirmed by Western blot analysis and immunohistochemistry.

RESULTS

The comparison of the proteins present before and after NAC revealed that 116 protein spots were significantly changed. In all, 31 proteins were analyzed by MS, and 15 proteins were upregulated in the cancer tissue after NAC relative to the level before NAC, whereas 16 proteins were downregulated after NAC. The significantly higher expression of peroxiredoxin 1 and significantly lower expression of galectin 1 after NAC treatment were confirmed by Western blot.

CONCLUSIONS

Proteomics can be used to identify the NAC-related proteins in squamous cervical cancer. The change in proteins may be associated with NAC exposure and response, but insight into their relevance requires further study.

Galectin 1 expression is associated with tumor invasion and metastasis in stage IB to IIA cervical cancer

Galectin 1 is a 14-kd laminin-binding lectin involved in important biologic mechanisms of tumors, including neoplastic transformation, cell survival, angiogenesis, cell proliferation, and metastasis. In this study, we investigated the role of galectin 1 in cell survival and metastasis in cervical cancer. The expression of galectin 1 was determined in 73 formalin-fixed, paraffin-embedded cervical cancer tissues using an immunohistochemical method and compared with clinicopathologic risk factors for recurrence after surgery. To evaluate the role of galectin 1 in cell proliferation and invasion, we performed proliferation and invasion assays with galectin 1 small interfering RNA (siRNA) using cervical cancer cell lines, including HeLa and SiHa cells. Immunohistochemical analysis revealed that galectin 1 expression was found in most peritumoral stroma samples (72/73; 98.6%). Galectin 1 expression was significantly correlated with the depth of invasion in the cervix (P=.015) and lymph node metastasis (P=.045) on univariate analysis. When progression-free survival of all of the patients studied was analyzed based upon galectin 1 expression, galectin 1 expression was not correlated with progression-free survival (P=.32). Down-regulation of galectin 1 using small interfering RNA resulted in the inhibition of cell growth and proliferation of HeLa and SiHa cells. Moreover, the ability of cells to invade was significantly reduced by galectin 1 small interfering RNA. Our results revealed that high galectin 1 expression in peritumoral stroma was significantly correlated with depth of invasion in cervical lesions and lymph node metastasis of cervical cancer and that galectin 1 may be functionally involved in cell proliferation and invasion.