Downregulation of the CXCR4 receptor inhibits cervical carcinoma metastatic behavior in vitro and in vivo

Integrative Systems Biology Approaches to Identify Potential Biomarkers and Pathways of Cervical Cancer

Nowadays, cervical cancer (CC) is treated as the leading cancer among women throughout the world. Despite effective vaccination and improved surgery and treatment, CC retains its fatality rate of about half of the infected population globally. The major screening biomarkers and therapeutic target identification have now become a global concern. In the present study, we have employed systems biology approaches to retrieve the potential biomarkers and pathways from transcriptomic profiling. Initially, we have identified 76 of each up-regulated and down-regulated gene from a total of 4643 differentially expressed genes. The up-regulatory genes mainly concentrate on immune-inflammatory responses, and the down-regulatory genes are on receptor binding and gamma-glutamyltransferase. The involved pathways associated with these genes were also assessed through pathway enrichment, and we mainly focused on different cancer pathways, immunoresponse, and cell cycle pathways. After the subsequent enrichment of these genes, we have identified 12 hub genes, which play a crucial role in CC and are verified by expression profile analysis. From our study, we have found that genes LILRB2 and CYBB play crucial roles in CC, as reported here for the first time. Furthermore, the survivability of the hub genes was also assessed, and among them, finally, CXCR4 has been identified as one of the most potential differentially expressed genes that might play a vital role in the survival of CC patients. Thus, CXCR4 could be used as a prognostic and/or diagnostic biomarker and a drug target for CC.

CXCR4 Antagonism Reduces Cardiac Fibrosis and Improves Cardiac Performance in Dilated Cardiomyopathy

Background: Myocardial fibrosis is a key pathologic finding in the failing heart and is implicated as a cause of increased ventricular stiffness and susceptibility to ventricular arrhythmia. Neurohormonal mediators such as aldosterone and angiotensin II are known to cause fibrosis in experimental models, however, clinical evidence for the reversal of fibrosis with relevant antagonists is limited. Recent studies suggest that inflammatory mediators may contribute to fibrosis. In dilated cardiomyopathy the mechanism for myocardial fibrosis is unclear and its implications on systolic function are not known. Methods and Results: We studied the effect of a highly selective antagonist of SDF-1/CXCR4 signaling, AMD3100, on the development of cardiac fibrosis and cardiac function in mice with dilated cardiomyopathy due to cardiac-specific transgenic overexpression of the stress-kinase, Mst1. AMD3100 significantly attenuated the progression of myocardial fibrosis and this was accompanied by significant improvements in diastolic and systolic performance as evaluated in isolated Langendorff perfused hearts. AMD3100 reduced BNP mRNA expression but did not alter the expression of Ca²⁺ handling genes. CXCR4 antagonism also reduced the abundance of splenic CD4⁺ T cells. Conclusion: This study demonstrates that CXCR4 pathway contributes to pathogenesis of cardiac fibrosis in dilated cardiomyopathy, and it represents a new potential therapeutic target in heart failure. The data also demonstrate that anti-fibrotic strategies can improve systolic performance.

Targeting the CXCL12/CXCR4 pathway and myeloid cells to improve radiation treatment of locally advanced cervical cancer

Cervical cancer is the fourth most commonly diagnosed cancer and the fourth leading cause of cancer death in women worldwide. Approximately half of cervical cancer patients present with locally advanced disease, for which surgery is not an option. These cases are nonetheless potentially curable with radiotherapy and cisplatin chemotherapy. Unfortunately, some tumours are resistant to treatment, and lymph node and distant recurrences are major problems in patients with advanced disease at diagnosis. New targeted treatments that can overcome treatment resistance and reduce metastases are urgently needed. The CXCL12/CXCR4 chemokine pathway is ubiquitously expressed in many normal tissues and cancers, including cervical cancer. Emerging evidence indicates that it plays a central role in cervical cancer pathogenesis, malignant progression, the development of metastases and radiation treatment response. Pre-clinical studies of standard-of-care fractionated radiotherapy and concurrent weekly cisplatin plus the CXCR4 inhibitor Plerixafor (AMD3100) in patient-derived orthotopic cervical cancer xenografts have shown improved primary tumour response and reduced lymph node metastases with no increase in early or late side effects. These studies have pointed the way forward to future clinical trials of radiotherapy/cisplatin plus Plerixafor or other newly emerging CXCL12 or CXCR4 inhibitors in women with cervical cancer.

Role and importance of the expression of transcription factor FOXC2 in cervical cancer

The aim of the present study was to investigate the relationship between the expression of transcription factor forkhead box C2 (FOXC2) and the clinical features of cervical cancer. A total of 66 patients with cervical cancer, 42 patients with cervical intraepithelial neoplasia (CIN) and 25 patients with cervical inflammation were enrolled. The positive expression rates and expression levels of mRNA of FOXC2, E-cadherin, N-cadherin, vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1), Notch protein and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) in cervical tissues were detected using immunohistochemistry and RT-PCR. The positive expression rates and expression levels of mRNA of FOXC2, N-cadherin, VEGF, SDF-1, Notch and LYVE-1 in cervical cancer were significantly higher than those in CIN, and those in the inflammatory tissues were the lowest, while the positive expression rate of E-cadherin in cervical cancer was lower than that in CIN, and that in the inflammatory tissues was the highest (P<0.05). The positive expression rates of FOXC2, N-cadherin, VEGF, SDF-1, Notch and LYVE-1 in patients with cervical cancer [human papillomavirus (HPV) positive, squamous cell carcinoma, Stages III–IV, maximal diameter ≥3.8 cm and low differentiation] were increased, and the positive expression rate of E-cadherin was decreased (P<0.05). Correlation analysis revealed that FOXC2 was positively correlated with the positive expression rates of N-cadherin, VEGF, SDF-1, Notch and LYVE-1, and negatively correlated with E-cadherin (P<0.05). In conclusion, the high expression of FOXC2 is correlated with the HPV infection, pathological pattern, clinical stage, tumor diameter and differentiation grade of cervical cancer, which may be involved in the epithelial-mesenchymal transition, vascular and matrix formation, Notch signaling pathway and lymphangiogenesis.

O-GlcNAcylation of NF-κB Promotes Lung Metastasis of Cervical Cancer Cells via Upregulation of CXCR4 Expression

C-X-C chemokine receptor 4 (CXCR4) stimulates cancer metastasis. NF-κB regulates CXCR4 expression in cancer cells, and O-GlcNAc modification of NF-κB promotes its transcriptional activity. Here, we determined whether CXCR4 expression is affected by O-GlcNAcylation of NF-κB in lung metastasis of cervical cancer. We found elevated levels of O-linked-N-actylglucosamine transferase (OGT) and O-GlcNAcylation in cervical cancer cells compared to those in non-malignant epithelial cells and detected increased expression of NF-κB p65 (p65) and CXCR4 in cervical cancer cells. Knockdown of OGT inhibited the O-GlcNAcylation of p65 and decreased CXCR4 expression levels in HeLa cells. Thiamet G treatment increased O-GlcNAcylated p65, which subsequently enhanced CXCR4 expression levels. Inhibition of O-GlcNAcylation by 6-Diazo-5-oxo-L-norleucine (DON) treatment decreased p65 activation, eventually inhibiting CXCR4 expression in HeLa cells. Lung tissues from mice engrafted with OGT-knockdown HeLa cells (shOGT) exhibited lower expression of Ki-67 and HPV E6 and E7 oncogenes compared to lung tissues from mice engrafted with control HeLa cells (shCTL). In addition, lung tissues from mice engrafted with shOGT cells exhibited lower p65 and CXCR4 immunoreactivity compared to tissues from mice engrafted with shCTL cells. Taken together, our data suggest that p65 O-GlcNAcylation promotes lung metastasis of cervical cancer cells by activating CXCR4 expression.

N-terminal polypeptide derived from vMIP-II exerts its antitumor activity by inhibiting the CXCR4 pathway in human glioma

Emerging evidence demonstrates that the stromal derived factor-1 (SDF-1α)/CXCR4 axis is associated with tumor aggressiveness and metastasis, including glioma, the most common brain cancer. In the present study, we demonstrated that a novel designed peptide NT21MP of viral macrophage inflammatory protein II, targeting CXCR4 inhibits SDF-1α-induced activation in glioma. The effects of NT21MP on CXCR4 expression, cell survival and migration were assessed on the human glioma cell line U251 and SHG-44 exposed to SDF-1α, by western blotting, MTT assay, flow cytometry and transwell migration assay. Our results illustrated that NT21MP inhibited SDF-1α induced proliferation, migration and invasion by upregulated pro-apoptotic genes (Bak1 and caspase-3) and downregulated Bcl-2/Bax as well as cell cycle regulators (cyclin D1 and CDK4) to arrest cell cycle in G0/G1 phase and promote apoptosis. By RT-qPCR and immunofluorescence we found that CXCR4 was highly expressed in SHG-44 cells. Our results from wound healing and transwell invasion assays indicated silencing of CXCR4 significantly inhibited the SDF-1α‑induced migration and invasion; similarly, flow cytometry showed that treatment with si-CXCR4 affected cell cycle and induced cell apoptosis in SHG-44. However, these effects were significantly weakened by NT21MP. In conclusion, the present study indicates that NT21MP plays a regulatory role in the SDF-1α/CXCR4 axis and further manages the invasion, migration, apoptosis and cell cycle of glioma cells. Thus, NT21MP might represent a novel therapeutic approach against glioma.

Plerixafor Improves Primary Tumor Response and Reduces Metastases in Cervical Cancer Treated with Radio-Chemotherapy

Purpose: There is an important need to improve the effectiveness of radio-chemotherapy (RTCT) for cervical cancer. The CXCL12/CXCR4 pathway can influence RT response by recruiting normal myeloid cells to the tumor microenvironment that in turn can exert radioprotective effects, and may promote metastases. The objective of this study was to explore the efficacy and toxicity of combining RTCT with CXCL12/CXCR4 inhibition in cervical cancer.Experimental Design: CXCR4 expression was measured in 115 patients with cervical cancer. Two primary orthotopic cervical cancer xenografts (OCICx) with different levels of CXCR4 expression were treated with RT (30 Gy: 15 daily fractions) and weekly cisplatin (4 mg/kg), with or without the CXCR4 inhibitor Plerixafor (5 mg/kg/day). The endpoints were tumor growth delay and lymph node metastases. Acute intestinal toxicity was assessed using a crypt cell assay.Results: There was a fivefold variation in CXCR4 mRNA expression in the patient samples, and good correlation between the expression in patients and in the xenografts. The combination of RTCT and Plerixafor produced substantial tumor growth delay and reduced lymph node metastases compared with RTCT alone in both of the xenograft models. There was a trend toward reduced acute intestinal toxicity with the addition of Plerixafor to RTCT. There were no changes in normal organ morphology to suggest increased late toxicity.Conclusions: This study demonstrates that the addition of Plerixafor to standard RTCT improves primary tumor response and reduces metastases in cervical cancer with no increase in toxicity. This combination warrants further investigation in phase I/II clinical trials. Clin Cancer Res; 23(5); 1242-9. ©2016 AACR.

MET receptor is a potential therapeutic target in high grade cervical cancer

Cervical cancer is one of the leading causes of death among women suffering from tumors. Current treatment options are insufficient. Here, we investigated the MET receptor as a potential molecular target in advanced cervical cancer. Downregulation of MET receptor expression via RNA interference in different cervical carcinoma cell lines dramatically decreased tumor growth and forced tumor differentiation in vivo. MET receptor silencing also led to a dramatic decrease in cell size and a decrease in proliferation rate under normal and stress conditions. MET receptor downregulation also resulted in decreased cyclin D1 and c-myc levels but did not increase apoptosis. Subsequent experiments showed that downregulation of the MET receptor decreased the expression of a key regulator of the epithelial-to-mesenchymal transition, SLUG. and increased the expression of E-cadherin, a hallmark of the epithelial phenotype. Moreover, MET downregulation impairs expression and signaling of CXCR4 receptor, responsible for invasive phenotype. Taken together, our results strongly suggest that the MET receptor influences the oncogenic properties of cervical carcinoma cells in vitro and in vivo. These findings highlight a unique role of the MET receptor in cervical carcinoma cells and indicate the MET receptor as a potential therapeutic target for advanced cervical carcinoma.

Evidence for induction of a tumor metastasis-receptive microenvironment for ovarian cancer cells in bone marrow and other organs as an unwanted and underestimated side effect of chemotherapy/radiotherapy

Background

One of side effects of chemotherapy and radiotherapy is the induction of several factors in various tissues and organs that create a pro-metastatic microenvironment for cancer cells that survive initial treatment.

Methods

In the present study, we employed human ovarian cancer cell line A2780 and immunodeficient mice xenogrfat model to test effect of both ibuprofen and dexamethasone to ameliorate the therapy-induced pro-metastatic microenvironment in bone marrow, liver, and lung.

Results

In our studies, we found that total body irradiation or administration of cisplatin increases the metastatic spread of human ovarian cancer cells transplanted into immunodeficient mice compared with animals unexposed to irradiation or cisplatin. Moreover, conditioned media harvested from irradiated murine bone marrow, lung, and liver chemoattracted human ovarian cancer cells, and this chemotactic activity was inactivated by heat, suggesting a major involvement of peptide or peptide-bound chemoattractants. We also observed that human ovarian cancer cells proliferate better if exposed to cell debris harvested from irradiated murine bone marrow. Finally, the pro-metastatic microenvironment in mice induced by radio- or chemotherapy was significantly ameliorated if animals were treated at the time of radiotherapy administration with non-steroid (ibuprofen) or steroid (prednisone) anti-inflammatory drugs.

Conclusions

In summary, we propose that a radiochemotherapy-induced, pro-metastatic microenvironment plays an important role in the metastasis of cancer cells that are resistant to treatment. Such cells have characteristics of cancer stem cells and are highly migratory, and simple, intensive, anti-inflammatory treatment by non-steroid agents to suppress induction of pro-metastatic factors after radiochemotherapy would be an interesting anti-metastatic treatment alternative.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-015-0141-7) contains supplementary material, which is available to authorized users.