Stefania Scala

Expression of CXCR4 Predicts Poor Prognosis in Patients with Malignant Melanoma

Purpose: CXCR4 receptor and its unique ligand, the CXCL12 chemokine, have been recently implicated in cancer metastasis. Evidence about the role of CXCR4/CXCL12 axis has been reported in several cancers including melanoma. Our goal was to investigate if CXCR4 expression has a prognostic value in malignant melanoma. Experimental Design: Immunohistochemical expression of CXCR4 was evaluated on 71 specimens of primary cutaneous melanoma with a Breslow tumor thickness of >1 mm after radical resection. Associations between baseline patient features and tumors were analyzed by χ2 test. The prognostic value of CXCR4 expression was evaluated by univariate and multivariate analyses adjusted by age, sex, Breslow tumor thickness, presence of ulceration, and sentinel lymph node metastases. Results: CXCR4 expression was detected in 31 of 71 (43.6%) primary cutaneous melanomas. Membrane or cytoplasmic staining for CXCR4 protein was absent in 56% of the tumors. The positive cases were divided into three score classes according to their staining: low in 15 cases (21%), moderate in 10 (14%), and high in 6 (8%). After a median follow-up of 38 months, 26 patients progressed (16 of 26 expressed CXCR4) and 19 died (12 of 19 expressed CXCR4). The CXCR4 expression on tumor cells was correlated with an unfavorable prognosis with a median disease-free and overall survival of 22 and 35 months, respectively. The hazard ratios of relapse and death, compared with patients with CXCR4-negative tumors, were 2.5 (95% confidence interval, 1.2-6.1) and 3.1 (95% confidence interval, 1.1-7.2), respectively. Median time-to-event (progression and survival) was not reached in patients with CXCR4-negative tumors. In the multivariate analysis, CXCR4 expression, presence of ulceration, and sentinel lymph node status emerged as independent prognostic factors. Conclusions: This article provides the first evidence that CXCR4 expression could be an independent and powerful prognostic marker in primary cutaneous malignant melanomas.

Overexpression of Both CXC Chemokine Receptor 4 and Vascular Endothelial Growth Factor Proteins Predicts Early Distant Relapse in Stage II-III Colorectal Cancer Patients

Purpose: CXC chemokine receptor 4 (CXCR4) and vascular endothelial growth factor (VEGF) are implicated in the metastatic process of malignant tumors. However, no data are currently available on the biological relationship between these molecules in colorectal cancer. We studied whether CXCR4 and VEGF expression could predict relapse and evaluated in vitro the contribution of CXCR4 in promoting clonogenic growth, VEGF secretion, and intercellular adhesion molecule-1 (ICAM-1) expression of colorectal cancer cells. Experimental Design: CXCR4 and VEGF were studied in colorectal cancer tissues and in Lovo, HT29, and SW620 colorectal cancer cell lines by immunohistochemistry. Correlations with baseline characteristics of patients and tumors were analyzed by χ2 test. VEGF secretion induced by CXCL12 was measured by ELISA. The effect of CXCL12 on ICAM-1 expression was evaluated by flow cytometry. Clonogenic growth induced by CXCL12 was determined by clonogenic assays. Functional effects induced by CXCL12 were prevented by the administration in vitro of AMD3100, a bicyclam noncompetitive antagonist of CXCR4. Results: Seventy-two patients, seen between January 2003 and January 2004, were studied. CXCR4 was absent in 16 tumors (22.2%); it was expressed in ≤50% of cells in 25 (34.7%) tumors and in >50% of cells in 31 (43.0%) tumors. VEGF was absent in 17 (23.6%) tumors; it was expressed in ≤50% of cells in 16 (22.2%) tumors and in >50% of cells in 39 (54.2%) tumors. There was a significant association between CXCR4 expression and lymph nodal status (P = 0.0393). There were significant associations between VEGF and tumor invasion (P = 0.0386) and lymph nodal involvement (P = 0.0044). American Joint Committee on Cancer stage (P = 0.0016), VEGF expression (P = 0.0450), CXCR4 expression (P = 0.0428), and VEGF/CXCR4 expression (P = 0.0004) had a significant prognostic value for disease-free survival with univariate analysis. The predictive ability of the American Joint Committee on Cancer stage and of the concomitant and high expression of VEGF and CXCR4 was confirmed by multivariate analysis. Prognosis is particularly unfavorable for patients whose primary tumors express CXCR4 and VEGF in >50% of cells (median disease-free survival in relapsed patients, 5.8 months; hazard ratio of relapse, 8.23; 95% confidence interval, 7.24-14.29). In clonogenic assays, CXCL12 (20 ng/mL/d) significantly increased the number of clones in SW620, HT29, and Lovo cells at 7 and 14 days. Again, CXCL12 was able to stimulate VEGF secretion in SW620, HT29, and Lovo cells as well as up-regulated ICAM-1. These effects were prevented by the administration of AMD3100 (1 μmol/L). Conclusions: We have shown that concomitant and high expression of CXCR4 and VEGF is a strong and independent predictor of early distant relapse in colorectal cancer. CXCR4 triggers a plethora of phenomena, including stimulation of clonogenic growth, induction of VEGF release, and ICAM-1 up-regulation. These data support the inhibition of CXCR4 to prevent the development of colorectal cancer metastasis.

HCV-related hepatocellular carcinoma: From chronic inflammation to cancer.

Hepatitis C virus (HCV) infection is a worldwide health problem because of its incidence and pathogenicity. It might evolve into chronic disease, cirrhosis, and/or hepatocellular carcinoma (HCC) and the outcome is mainly determined by the host immune response. For viral clearance, combined innate and adaptive immune responses are required; resolution requires a vigorous, durable, polyclonal CD4(+) and CD8(+) T-cell response, with an increase in virus-specific CD8(+) T cells or cytotoxic T lymphocytes. Failure of efficient immune response can lead to chronic inflammation, tissue remodeling through cell growth, apoptosis and/or necrosis and induction of oxidative stress. Development of fibrosis and/or cirrhosis plus a microenvironment conducive to genomic instability mutations will promote neoplastic transformation. System governance derives from cellular (regulatory cells) and humoral (cytokines and chemokines) immune networks. Therefore, HCC pathogenesis may be a model to study the disease progression from chronic inflammation to cancer allowing design of new strategies targeting the immune response, thereby modifying disease outcome.

Human Melanoma Metastases Express Functional CXCR4

Purpose: The chemokine receptor CXCR4 was identified as an independent predictor of poor prognosis in primary melanoma. The aim of the study was to investigate the role of CXCR4 in human melanoma metastases. Experimental Design: CXCR4 expression was evaluated in melanoma metastases and in metastatic cell lines through immunohistochemistry, immunoblotting, immunofluorescence, and reverse transcription-PCR. The function of CXCR4 was tested in the presence of the ligand, CXCL12, through induction of extracellular signal-regulated kinase-1 and -2 (Erk-1 and -2) phosphorylation, proliferation, apoptosis, and migration capabilities. Results: CXCR4 expression was detected in 33 out of 63 (52.4%) metastases from cutaneous melanomas. Metastatic melanoma cell lines expressed cell surface CXCR4; PES 43, Alo 40, and COPA cell lines showed the highest levels of CXCR4 (>90% of positive cells); PES 41, Alo 39, PES 47, POAG, and CIMA cell lines showed low to moderate degrees of expression (5-65% of positive cells). Other chemokine receptors, CCR7 and CCR10, were detected on the melanoma cell lines; CXCL12 activated Erk-1 and Erk-2, the whose induction was specifically inhibited by AMD3100 treatment. CXCL12 increased the growth in PES 41, PES 43, and PES 47 cells under suboptimal (1% serum) and serum-free culture conditions; AMD3100 (1 μmol/L) inhibited the spontaneous and CXCL12-induced proliferation. No rescue from apoptosis was shown but PES 41, PES 43, and PES 47 cells migrate toward CXCL12. Conclusions: These findings indicate that CXCR4 is expressed and active in human melanoma metastases, suggesting that active inhibitors such as AMD3100 may be experienced in human melanoma.

Reduced drug accumulation and multidrug resistance in human breast cancer cells without associated P-glycoprotein or MRP overexpression

MCF‐7 human breast cancer cells selected in Adriamycin in the presence of verapamil developed a multidrug resistant phenotype, which was characterized by as much as 100,000‐fold resistance to mitoxantrone, 667‐fold resistance to daunorubicin, and 600‐fold resistance to doxorubicin. Immunoblot and PCR analyses demonstrated no increase in MDR‐1 or MRP expression in resistant cells, relative to parental cells. This phenotype is similar to one previously described in mitoxantrone‐selected cells. The cells, designated MCF‐7 AdVp, displayed a slower growth rate without alteration in topoisomerase IIα level or activity. Increased efflux and reduced accumulation of daunomycin and rhodamine were observed when compared to parental cells. Depletion of ATP resulted in complete abrogation of efflux of both daunomycin and rhodamine. No apparent alterations in subcellular daunorubicin distribution were observed by confocal microscopy. No differences were noted in intracellular pH. Molecular cloning studies using DNA differential display identified increased expression of the alpha subunit of the amiloride‐sensitive sodium channel in resistant cells. Quantitative PCR studies demonstrated an eightfold overexpression of the alpha subunit of the Na+ channel in the resistant subline. This channel may be linked to the mechanism of drug resistance in the AdVp cells. The results presented here support the hypothesis that a novel energy‐dependent protein is responsible for the efflux in the AdVp cells. Further identification awaits molecular cloning studies. J. Cell. Biochem. 65:513–526.

Inhibitory effects of anti-CXCR4 antibodies on human colon cancer cells.

Background: CXCR4, the chemokine receptor for CXCL12, has recently been involved in the metastatic process of several neoplasms. Materials and methods: The expression of CXCR4 was evaluated by immunohistochemistry of colorectal tissue samples and by flow cytometry on Caco2, GEO, SW480, SW48, Lovo and SW620 human colon carcinoma cell lines. Correlations with pathological characteristics of the specimens were analysed with chi-square test. To verify the functional status of CXCR4, cell lines were tested in adhesion, migration, and proliferation assays. Results: We studied the expression of CXCR4 in 88 human colorectal tissues and we found that CXCR4 was expressed in >10% of epithelial cells in 50% of normal mucosae (7/14), in 55% of polyps (29/53), in all of carcinomas (16/16) and hepatic metastasis (5/5). Notably, CXCR4 was significantly over-expressed in cancerous lesions (carcinomas and metastasis) compared to non-cancerous lesions (normal mucosa and polyps) (P=0.003) and in adenomatous polyps versus hyperplastic polyps (P=0.009). The diameter of a polyp was also significantly associated with CXCR4 expression (P=0.031). SW480, SW48 and SW620 cell lines showed the highest levels of CXCR4 (60–80% of positive cells). Adhesion, migration, and proliferation increased in response to the CXCL12 chemokine. These effects were abrogated by the addition of anti-CXCR4 antibodies. Further, CXCL12 activated ERK1/2 in SW480 cells. Conclusions: These data suggest that CXCR4 might play a role in colon cancer cell properties and that anti-CXCR4 antibodies could have therapeutic effects against colorectal cancer.

Detection, monitoring, and management of trastuzumab-induced left ventricular dysfunction: an actual challenge.

The antibody trastuzumab, targeted to inhibit the signalling of ErbB2, a tyrosine kinase receptor overexpressed in 20–30% of breast cancers, improves the prognosis in women affected by this tumour, but produces cardiotoxicity, since ErbB2 is also involved in myocardial homeostasis. In this review, we discuss the pathophysiology of trastuzumab cardiomyopathy and the complex interplay between ErbB2 inhibition and anthracyclines, and we focus on the actual challenges of detecting, monitoring, and managing trastuzumab cardiotoxicity: the research of new, sensitive markers of early trastuzumab toxicity, before the ejection fraction is reduced, is an active field of research.

Molecular Pathways: Targeting the CXCR4–CXCL12 Axis—Untapped Potential in the Tumor Microenvironment

Evidence suggests that the CXC–chemokine receptor-4 pathway plays a role in cancer cell homing and metastasis, and thus represents a potential target for cancer therapy. The homeostatic microenvironment chemokine CXCL12 binds the CXCR4 and CXCR7 receptors, activating divergent signals on multiple pathways, such as ERK1/2, p38, SAPK/JNK, AKT, mTOR, and the Bruton tyrosine kinase (BTK). An activating mutation in CXCR4 is responsible for a rare disease, WHIM syndrome (warts, hypogammaglobulinemia, infections, and myelokathexis), and dominant CXCR4 mutations have also been reported in Waldenstrom macroglobulinemia. The CXCR4–CXCL12 axis regulates the hematopoietic stem cell niche—a property that has led to the approval of the CXCR4 antagonist plerixafor (AMD3100) for mobilization of hematopoietic precursors. In preclinical models, plerixafor has shown antimetastatic potential in vivo, offering proof of concept. Other antagonists are in preclinical and clinical development. Recent evidence demonstrates that inhibiting CXCR4 signaling restores sensitivity to CTLA-4 and PD-1 checkpoint inhibitors, creating a new line for investigation. Targeting the CXCR4–CXCL12 axis thus offers the possibility of affecting CXCR4-expressing primary tumor cells, modulating the immune response, or synergizing with other targeted anticancer therapies. Clin Cancer Res; 21(19); 4278–85. ©2015 AACR.

Concomitant CXCR4 and CXCR7 Expression Predicts Poor Prognosis in Renal Cancer

CXCR4 is a chemokine receptor implicated in the metastatic process. The CXCR4 ligand, CXCL12, was shown to bind also the CXCR7 receptor, a recently deorphanized chemokine receptor whose signalling pathway and function are still controversial. This study was conducted to determine patients clinic-pathological factors and outcome according to the expressions of CXCR4 and CXCR7 in renal cell carcinoma (RCC). CXCR4 and CXCR7 expression was evaluated in 223 RCC patients through immunohistochemistry; moreover CXCR4 and CXCR7 was detected in 49 others consecutive RCC patients trough RT- PCR. CXCR4 expression was low in 42/223 RCC (18.8%), intermediate in 71/223 (31.9%) and high in 110/223 (49.3%). CXCR7 expression was low in 44/223 RCC patients (19.8%), intermediate in 65/223 (29.1%) and high in 114/223 (51.1%). High CXCR4 and high CXCR7 expression predicted shorter disease free survival. In multivariate analysis, high CXCR4 expression (p= 0.0061), high CXCR7 (p= 0.0194) expression and the concomitant high expression of CXCR4 and CXCR7 (p= 0.0235) are independent prognosis factors. Through RT-PCR, CXCR4 was overexpressed in 36/49 and CXCR7 in 33/49 samples correlating with symptoms at diagnosis and lymph nodes status. So we can hypothesize that CXCR4 and CXCR7, singularly evaluated and in combination, are valuable prognostic factors in RCC patients.

Differential role of CD133 and CXCR4 in renal cell carcinoma

The chemokine receptor CXCR4 and CD133, putative stem cell markers, were previously described in renal cancer (RCC). To evaluate the biological and prognostic role of CD133 and CXCR4 in RCC the expression was evaluated through qPCR and immunoblotting in human renal cancer cell lines (786-O, A498, ACHN, CAKI-1, SN12C, TK10, UO31) and patients biopsies. Renal cancer cells and surgical biopsies expressed functional CXCR4 while CD133 was not detectable. CXCR4 and CD133 expression was then evaluated in 240 renal cancer patients through immunohistochemistry. CXCR4 and CD133 were low in 19.1% and 59.6%; intermediate in 20% and 17.9%; high in 60.8% and 22.5% of the cases, respectively. CXCR4 was overexpressed in tumours (p= 0.02), while CD133 was over expressed in healthy tissues (p= 0.04). Disease free survival Kaplan Meier plots suggest that prognosis is unfavourable for patients whose primary tumours express CXCR4 (p= 0.0199) but nor CD133 (p= 0.151) neither the concomitant CXCR4-CD133 (p=0.848) high expression affected prognosis. Analysis of prognostic factors suggests that age, clinical presentation, AJCC stage and CXCR4 had a significant prognostic value at the univariate analysis. The CXCR4 predictive ability was confirmed at the multivariate analysis while no prognostic role was identified for CD133. Thus concomitant CD133 and CXCR4 evaluation is not worth in RCC patient while the CXCR4 prognostic role encourage CXCR4 antagonists as promising therapeutic option.