Expression of Chemokine Receptor CCR6 as a Molecular Determinant of Adrenal Metastatic Relapse in Patients With Primary Lung Cancer

BackgroundRecent studies suggest that chemokines are involved in organ-specific metastatic relapse. We evaluated the potential implications of chemokine receptors in the development of adrenal metastasis after complete resections of primary non–small-cell lung cancer.Patients and MethodsWe studied a unique cohort of 21 primary lung cancers with matched adrenal metastases for the expression of CX3CR1, CXCR4, CCR6, and CCR7, using immunohistochemistry.ResultsAlthough CXCR4, CX3CR1, and CCR7 were independently expressed in primary and corresponding metastases, CCR6 was clearly overexpressed in adrenal metastases, compared with corresponding primary tumors. Moreover, CCL20, the ligand of CCR6, was preferentially expressed in adrenal tissues that developed metastases.ConclusionWe report for the first time (to the best of our knowledge) a potential role for the CCR6 receptor in the organ orientation of the development of metastases in lung cancer. We demonstrated a statistically significant overexpression of CCR6 in adrenal metastases compared with primary lung tumors, indicating that the increased production of CCL20 in adrenal glands might contribute to the selective recruitment of CCR6-expressing cancer cells in lung cancer. This study, in concordance with the data obtained in animal models, suggests that the chemokine receptor family constitutes a biologic support of the “seed and soil” theory.     

CCR7 and CXCR4 as novel biomarkers predicting axillary lymph node metastasis in T1 breast cancer.

PURPOSE: The chemokine receptors CCR7 and CXCR4 have been shown to play an important role in cancer metastasis. We therefore studied the differential expression of CCR7 and CXCR4, along with that of the biomarker HER2-neu, to evaluate whether these biomarkers could predict axillary lymph node metastasis in breast cancer. EXPERIMENTAL DESIGN: Biomarker expression levels were evaluated using paraffin-embedded tissue sections of lymph node-negative (n = 99) and lymph node-positive (n = 98) T1 breast cancer by immunohistochemical staining. RESULTS: Lymph node-positive tumors showed higher rates of high cytoplasmic CCR7 staining (21.5% versus 8.5%, P = 0.013) and HER2-neu overexpression (21.5% versus 9.3%, P = 0.019) than did lymph node-negative tumors. Similarly, high cytoplasmic CXCR4 expression occurred more commonly in lymph node-positive tumors (11.2% versus 5.1%, P = 0.113). In contrast, predominantly nuclear CXCR4 staining was more likely to be found in lymph node-negative tumors (54.5% versus 37.8%, P = 0.018). Furthermore, cytoplasmic CXCR4 coexpressed with HER2-neu was the only factor associated with involvement of four or more lymph nodes (16.7% versus 1.2%, P = 0.04) among lymph node-positive tumors. When all three biomarkers (CCR7, CXCR4, HER2-neu) were utilized together, 50.0% of lymph node-positive tumors highly expressed one of these biomarkers compared with 18.8% of the lymph node-negative tumors (P < 0.0001). CONCLUSIONS: Our results suggest that the chemokine receptor CCR7 is a novel biomarker that can predict lymph node metastases in breast cancer. Utilization of additional markers, such as CXCR4 and HER2-neu, further improves the prediction of the presence and extent of lymph node involvement.     

Effect of pro-inflammatory cytokine stimulation on human breast cancer: Implications of chemokine receptor expression in cancer metastasis

Interactions between tumour cells and microenvironments may affect their growth and metastasis formation. In search for a better understanding of the role of cellular mediators in the progression of cancer, we investigated the effect of pro-inflammatory cytokines IL-1, IL-6, TNF-α and IFN-γ on the regulation of expression of chemokine receptors CXCR4, CXCR2, CX3CR1, CCR9, and CCR5 in the human breast cancer cell line MCF-7. Our results showed that IL-1 increased CXCR4 expression whereas TNF-α increased CX3CR1, CCR9 and CCR5. Interestingly, this regulation was not homogeneous, emphasizing the inherent heterogeneity in cancer that may be responsive to specific inflammatory microenvironments.     

Expression of growth factor and chemokine receptors: new insights in the biology of inflammatory breast cancer.

PURPOSE: Recent studies have indicated that expression of chemokine receptors CXCR4 and CCR7 could be an indicator of the metastatic potential of breast cancer. Expression of CXCR4 and CCR7 along with the biomarkers HER2-neu and epidermal growth factor receptor (EGFR) was investigated in inflammatory breast cancer (IBC) to evaluate their prognostic implications. EXPERIMENTAL DESIGN: CXCR4, CCR7, and EGFR were evaluated by immunohistochemical staining (IHC) of paraffin-embedded tissue sections. HER2-neu amplification was assessed by FISH and/or IHC. All patients received chemotherapy, surgery, and radiation. RESULTS: Forty-four cases diagnosed with IBC from 1994 to 2002 were included in the study. In all, 18 (40.9%) patients had positive CXCR4, 10 (22.7%) had positive CCR7, 21 (47.7%) had positive HER2-neu, and EGFR was positive in 12 of 40 patients (30%). The 5-year overall survival (OS) was 24.8% for CXCR4-positive disease versus 42.3% for CXCR4-negative patients (P = 0.53) and 20.0% for CCR7-positive disease versus 41.9% for CCR7-negative patients (P = 0.24). EGFR-positive disease had significantly worse OS compared with EGFR-negative disease (P = 0.01). CONCLUSIONS: These data demonstrate the expression of growth factor and chemokine receptors in IBC. The expression of these receptors is associated with increased risk of recurrence and death, and thus, they may represent potential therapeutic targets in IBC.     

Association of CXCR4 and CCR7 chemokine receptor expression and lymph node metastasis in human cervical cancer.

BACKGROUND: The chemokine receptors CXCR4 and CCR7 have been suggested to play an important role in cancer invasion and metastasis. The expression of these receptors in human cervical cancer, however, has seldom been characterized. PATIENTS AND METHODS: We investigated the expression of CXCR4 and CCR7 in cervical cancer specimens and determined the association between their expression and the clinicopathological features observed, including patient outcome. RESULTS: CXCR4 expression was significantly higher in elderly patients (P=0.025); it was also significantly increased in patients with cancers displaying large tumor size (P=0.010), deep stromal invasion (P=0.0004), lymph-vascular space involvement (P=0.0002), or lymph node metastasis (P<0.0001). CCR7 expression was significantly higher in cases of squamous cell carcinomas (P=0.010) and in patients with cancers showing large tumor size (P<0.0001), deep stromal invasion (P<0.0001), vaginal invasion (P=0.047), lymph-vascular space involvement (P=0.012), or lymph node metastasis (P<0.0001). Logistic regression analysis revealed that deep stromal invasion (P=0.017) and CXCR4 (P=0.016) and CCR7 (P=0.022) expression were independent factors that influenced pelvic lymph node metastasis. The disease-free survival and overall survival (OS) rates of patients exhibiting both CXCR4 and CCR7 expression were significantly reduced (P<0.0001). In addition, the expression of both CXCR4 and CCR7 was an independent prognostic factor for OS (95% confidence interval=1.03-17.86; P=0.046). CONCLUSIONS: CXCR4 and CCR7 expression may be associated with lymph node metastasis; moreover, the expression of these receptors can serve as an indicator of poor prognosis in patients with cervical cancer.     

Effect of chemokine receptors CXCR4 and CCR7 on the metastatic behavior of human colorectal cancer.

PURPOSE: The expression of chemokine receptors CXCR4 and CCR7 has been associated with tumor dissemination and poor prognosis in a limited number of tumor entities. However, no data are currently available on the impact of chemokine receptor expression on disease progression and prognosis in human colorectal cancer.EXPERIMENTAL DESIGN: The expression of CXCR4 and CCR7 was evaluated in 96 patients with histologically confirmed colorectal cancers and in four colorectal cancer cell lines by immunohistochemical staining. Furthermore, cell migration assays were done with SW480, SW620, and LS174T cancer cells to confirm the effect of the CXCR4 ligand stromal cell-derived factor 1alpha on migration.RESULTS: Human colorectal cancer specimens and cell lines displayed a CXCR4 and CCR7 expression with variable intensities. Interestingly, strong expression of CXCR4, but not of CCR7, was significantly associated with higher Union International Contre Cancer stages 3/4 (P = 0.0017), lymph node metastasis (P = 0.00375), and distant metastasis (P = 0.00003) and further correlated with a reduced 3-year survival rate (P = 0.1). Strong CXCR4 and CCR7 expression positively correlated with the location of the primary tumor in the rectum (P < 0.01). Furthermore, activation of CXCR4-expressing cancer cells by stromal cell-derived factor 1alpha resulted in a significant increase of cell migration (P < 0.014).CONCLUSION: Strong expression of CXCR4 by colorectal cancer cells is significantly associated with lymphatic and distant dissemination in patients with colorectal cancer as well as with cancer cell migration in vitro.     

Involvement of chemokine receptor CCR6 in colorectal cancer metastasis.

Various chemokine receptors, namely CXCR4, CCR6 and CCR7, have recently been shown to be involved in the regulation of metastasis in malignant tumors. However, little is known about the role of these receptors in promoting tumor metastasis of colorectal cancer (CRC) to the primary site of CRC metastasis in the liver. To investigate this issue, we analyzed the expression of the chemokine receptors CXCR4, CCR6 and CCR7 in colorectal tumors and colorectal liver metastases. In the present study, 30 human cancer samples from colorectal tissue, 30 human samples from colorectal liver metastases and the adjacent nontumorous liver tissues were screened using quantitative real-time PCR, Western blot analysis, histochemistry, microdissection and the enzyme-linked immunosorbent assay (ELISA). While an overexpression of all the chemokine receptors was found in CRC, in colorectal liver metastases only the chemokine receptors CXCR4 and CCR6 were significantly upregulated. Consequently, we investigated the expression of the corresponding ligands CXCL12/SDF1alpha, CCL20/MIP3alpha, CCL19/MIP3beta and CCL21/6Ckine in various organs, such as the stomach, esophagus, pancreas, colon and rectum, in comparison with their expression in the liver as the primary site of metastatic spread in CRC. We found that only CCL20 exhibits peak levels of expression in the liver, thus indicating that an increased production of CCL20 may contribute to the selective recruitment of CCR6-expressing cancer cells in CRC. Furthermore, we could demonstrate that CRC patients who developed liver metastases express significantly more CCL20 and CCL21 in the liver in comparison with an unaffected control group. Therefore, our findings strongly suggest an association between CCL20/CCR6 expression in human CRC and the promotion of colorectal liver metastasis.     

Messenger RNA expression levels of CXCR4 correlate with metastatic behavior and outcome in patients with osteosarcoma.

PURPOSE: To determine if osteosarcoma cells express chemokine receptors and if their presence or absence relates to clinical features. EXPERIMENTAL DESIGN: Using fluorescent quantitative real-time PCR, the pattern of 17 chemokine receptors in 3 osteosarcoma cell lines and 68 osteosarcoma patient samples was analyzed. RESULTS: The expression of the chemokine receptors was generally low among the cell lines. In the high-grade osteosarcoma patient samples (n = 47), CXCR4 was the most commonly expressed (63%) and its expression level was inversely correlated to overall survival (P < 0.0001), event-free survival (P < 0.001), and metastasis-free survival (MFS; P = 0.002). There was also a correlation between the expression level of CXCR4 and the presence of metastasis at diagnosis (P = 0.002). CCR7 was expressed in 43% of the samples and its expression level was inversely correlated with overall survival (P = 0.03) and MFS (P = 0.007). CCR10 mRNA expression level was inversely correlated with MFS (P = 0.009). There was no association between the expression of CXCR4, CCR7, and CCR10. Of the 26 samples studied for stromal cell-derived factor-1 expression, 77% expressed it, but there was no correlation with the clinical variables or CXCR4 expression. Multivariate analysis revealed that mRNA expression level of CXCR4 was the only significant variable for overall survival (P = 0.0006), event-free survival (P = 0.004), and MFS (P = 0.025). CONCLUSIONS: These data suggest that CXCR4 could be useful as a prognostic factor and as a predictor of potential metastatic development in osteosarcoma. If further studies confirm that it is relevant to metastases in this disease, it could represent a new therapeutic target.     

Correlation effect of EGFR and CXCR4 and CCR7 chemokine receptors in predicting breast cancer metastasis and prognosis

Background

The chemokine receptors CXCR4 and CCR7 play an important role in cancer invasion and metastasis. This study investigated the expression of CXCR4, CCR7, CXCL12, CCL21, and EGFR to illustrate the role of these biomarkers in breast cancer metastasis and prognosis.

Methods

The CXCR4, CCR7, CXCL12, CCL21, and EGFR biomarkers were analyzed along with ER, PR, and HER-2/neu in breast cancer tissue microarray (TMA) specimens, including 200 primary breast cancer specimens by immunohistochemistry. Corresponding lymph nodes from the same patients were also examined using the same method.

Results

Together with their CXCL12 and CCL21 ligands, CXCR4 and CCR7 were significantly highly expressed in tumor cells with lymph node (LN) metastasis. Similarly, EGFR was expressed highly in tumors with LN metastasis. The ligands were especially expressed in metastatic tumors than in primary tumors from the same patients. Moreover, the expression of both CXCR4 accompanied by CCR7 and CXCL12 accompanied by CCL21 were up-regulated. Kaplan-Meier survival analysis revealed that patients exhibiting high CXCR4, CCR7, and EGFR expression experienced a shorter survival period compared with those with low expression.

Conclusions

The expression of CXCR4, CCR7, and EGFR may be associated with LN metastasis. Moreover, the expression of these receptors can serve as an indicator of undesirable prognosis in patients with breast cancer.     

Chemokine C–X–C motif receptor 6 contributes to cell migration during hypoxia

The chemokine and chemokine receptor families have important roles in tumorigenesis. Although CXCR4 and CCR7 have been reported to be associated with cancer metastasis, the role of other chemokine receptors in cancer is poorly understood. We explored the status of CXCR6 in hypoxia-induced cell migration. Breast cancer cells and human umbilical vein endothelial cells (HUVEC) expressed CXCR6, and showed appreciable chemotactic migration to CXCL16. Significant accumulation of CXCR6 mRNA and protein during hypoxia was observed. Overexpression of CXCR6 increased cell migration, and knockdown of CXCR6 attenuated hypoxia-mediated cell migration and MMP-2 secretion. To investigate possible mechanisms regulating CXCR6 expression during hypoxia, we detected the expression of HIFs and found that HIF-1α was involved in CXCR6 regulation. CXCR6 and HIF-1α were highly expressed in breast cancer lymph nodes metastases. Our data suggest CXCR6 contributes significantly to cell migration during hypoxia.     

Risk Factors,Patterns, and Distribution of Bone Metastases and Skeletal-Related Events in High-Risk Breast Cancer Patients

Background: More than a quarter of breast cancer patients are at risk to develop recurrent metastases to the bone. Objective: This study was designed to identify risk factors and predilections of bone metastasis and skeletal-related events (SRE) in a population of breast cancer survivors initially diagnosed in advanced stages and with high-risks of relapse. Methods: Associated risk factors, distribution, and attainable treatment of bone metastasis and SRE were analyzed in a cohort of 1,329 breast cancer patients. The association with dependent variables was subsequently analyzed using multivariable logistic regression. Sociodemographic and adverse clinical characteristics were included as covariates of progression into bone metastasis and SREs. Results: Of 1329 breast cancer patients, 246 patients (18.5%) were diagnosed as metastatic breast cancer in which 232 of them (94.3%) had bone metastases. Spines were the most common sites of bone metastases (25.6%). In multivariable analysis, advanced stage at diagnosis (OR=1.840, 95%CI:1.198-2.826, P=0.005), luminal subtype (OR=1.788, 95%CI:1.206-2.652, P=0.045), lobular histology (OR=1.795, 95%CI:1.012-3/184, P=0.046), positive axillary lymph node (OR=1.771, 95%CI:1.087-2.886, P=0.022), multiple metabolic comorbidities (OR=2.193, 95%CI:1.371-3.508, P=0.001), early menopause (OR=2.136, 95%CI:1.116-4.464, P=0.046) were significantly associated with risk of recurrent bone metastases. SREs occurred in 89 (68.5%) patients. Several risk factors for SREs were early menopausal age (OR=2.342, P=0.024), advanced stages (OR=1.404, P=0.039), lobular histology (OR=2.279, P=0.007), and having multiple metabolic comorbidities (OR=1.728, P=0.039). Conclusion: Bone metastases and SREs are relatively high in breast cancer patients diagnosed in advanced stages. Luminal subtypes, having multiple metabolic comorbidities, and lobular histology are associated with higher risks of recurrent bone metastases. Living in rural areas and advanced stage at diagnosis as a risk factors for bone metastases might represent a social gradient of care delivery.     

Expression of chemokine receptors in human gastric cancer.

The roles of chemokine receptors in cancer metastatic processes continue to draw research attention. Here we evaluated the expression profiles of the chemokine receptors CCR7 and CXCR4 in gastric cancer, and their potential use as prognostic markers. The expressions of CCR7 and CXCR4 mRNA were analyzed by RT-PCR in 10 human gastric cancer cell lines and in 43 gastric cancer tissues, and in an additional 307 gastric cancer tissues by immunohistochemistry. Clinicopathological features and the prognoses of patients were also evaluated versus the expression of these two cytokine receptors. CCR7 and CXCR4 mRNA were found to be expressed in all gastric cancer cell lines, whereas their mRNA expression rates in gastric cancer tissues were 83.7% (36/43) and 100% (43/43), respectively. Immunohistochemical staining of the 307 gastric cancer tissues showed that the expression rates of CCR7 and CXCR4 were 22.5% (69/307) and 36.5% (112/307), respectively. Multivariate analysis of the immunohistochemistry results showed that the expression rate of CCR7 was significantly higher in differentiated than in undifferentiated gastric cancertypes (35.1 vs. 15.3%, p<0.001), and that CXCR4 was expressed at a higher rate in intestinal cancer than in diffuse-type cancer (58.8 vs. 22.3%, p<0.001). However, in contrast to previous studies, the expressions of CCR7 or CXCR4 were not associated with lymph node metastasis. Moreover, the prognosis of patients with CCR7-positive tumors was better than that of patients with CCR7-negative tumors, but no such correlation was observed for CXCR4 expression. In conclusion, the expressions of the chemokine receptors CCR7 and CXCR4 were found to be high in differentiated and intestinal-type gastric cancers, respectively.     

The Significance of CXCR4 Expression for the Prediction of Lymph Node Metastasis in Breast Cancer Patients

OBJECTIVE The chemokine receptor(CXCR4)CXC chemokine receptor 4)plays an important role in cancer metastasis.We therefore studied differential expression of the CXCR4,as well as that of the biomarker HER2,so as to evaluate whether these biomarkers can be used to predict axillary lymph node metastasis in breast cancer patients. METHODS Immunohistochemistry was used to evaluate the CXCR4 and HER2 expressions and to examine the paraffin sections of the breast cancers at various stages.Positive lymph node expression was found in 80 of the cases,and in 7 there was negative expression. RESULTS Compared to the cases with negative lymph nodes, there was a high expression of CXCR4(26.3% vs.14.3%,P=0.013), and an over-expression of HER2(28.8% vs.14.3%,P=0.011). Moreover,there was a direct correlation between the CXCR4 and HER2 expressions and the tumor staging(P=0.000)and lymph node metastasis(P=0.032).When the two biomarkers,i.e.CXCR4 and HER2,were concurrently labeled,a high expression of one of the biomarkers could be seen in the cases with positive lymph nodes(51.3% vs.28.6%,P<0.003). CONCLUSION The chemokine receptor,CXCR4,is a new-type biomarker in predicting axillary lymph-node metastasis in breast cancers.Compared with the other markers,such as HER2 etc., assessment of CXCR4 can improve the prediction of the presence and extent of lymph node involvement.     

Rab5A is associated with axillary lymph node metastasis in breast cancer patients

The expression of Rab proteins has been associated with cancer. However, few data are available on Rab5A expression in human breast cancer or its impact on disease progression. First, we examined the functional role of Rab5A in breast cancer cells. The expression of Rab5A in MDA-MB-231 cells can be stimulated by epidermal growth factor in a dose-dependent manner. The epidermal growth factor-induced increase of Rab5A expression correlated well with enhanced migration in wound healing migration assays in these cells. Furthermore, we evaluated the expression of Rab5A in breast cancer specimens using immunohistochemical staining, then analyzed the relationship between the expression of Rab5A and clinicopathological parameters. The increased expression of Rab5A protein in 123 breast cancer samples was associated with higher histological grade (P = 0.004), more lymphovascular invasion (P = 0.027), more axillary lymph node (LN) metastasis (P = 0.008), and a higher number of axillary LN metastases (P = 0.043). Among 218 axillary LNs of more than 10 breast cancer patients with node metastases, 167 metastatic LNs were found to have increased Rab5A expression. Rab5A is associated with axillary LN metastasis in breast cancer patients.     

Chemokines in neoplastic progression

Chemokines and their receptors have emerged as attractive targets regulating the migration of tumor cells in vivo, a process known as cancer metastasis. The control of metastasis is critical to the control of cancer progression. Two chemokine receptors and their ligands stand out as likely targets for therapeutics: CCR7/CCL21 for lymph node metastases, and CXCR4/CXCL12 for lung, liver, bone marrow, and brain metastases. The most widely expressed chemokine receptor among cancers is likely to be CXCR4.     

Expression of chemokine receptors by cancer cells

Chemokine receptors are involved in the trafficking of leucocytes. It has been shown recently that chemokine receptors (CXCR4, CCR7...) are expressed by breast cancer cells and could be involved in the metastasis phenomenon. Since this discovery, new data have been generated in this topic. These data confirm that chemokine receptors are involved in the occurrence of metastases, suggest that their expression is regulated by genes involved in the carcinogenesis and/or angiogenesis (VHL...) and that inhibitors could be of interest in the treatment of breast cancer. In this paper, we will review all these data and will discuss the perspectives that opens this new concept.     

Expression of CXC chemokine receptor-4 enhances the pulmonary metastatic potential of murine B16 melanoma cells

The chemokine receptors CC chemokine receptor (CCR) 7 and CXC chemokine receptor (CXCR) 4 have been implicated in cancer metastasis. To evaluate whether CXCR4 is sufficient to increase tumor metastasis in an organ-specific manner, we transduced murine B16 melanoma cells with CXCR4 (CXCR4-B16) and followed the metastatic fate of the transduced cells in both i.v. and s.c. inoculation models of metastasis. CXCR4-B16 cells demonstrated marked increases (>10-fold) in pulmonary metastasis compared with vector (pLNCX2)-B16 after i.v. and s.c. inoculation of tumor cells. The increase in metastasis could be completely inhibited by T22, a small peptide antagonist of CXCR4. As early as 24 and 48 h after i.v. injection, CXCR4-B16 cells were significantly increased in the lung compared with control B16 cells by 5- and 10-fold (P < 0.05), respectively. CXCR4-B16 cells adhered better to both dermal and pulmonary microvascular endothelial cells relative to control B16 cells. Moreover, CXCL12 promoted the growth of CXCR4-B16 cells in vitro. Whereas expression of CXCR4 in B16 cells dramatically enhanced pulmonary metastasis, metastasis to the lymph nodes, liver, and kidney was rare. Immunohistochemical staining of both primary human cutaneous melanoma and pulmonary metastases revealed CXCR4 expression. Thus, CXCR4 plays a potentially important role in promoting organ-selective metastasis, possibly by stimulating tumor adhesion to microvascular endothelial cells and by enhancing the growth of tumor cells under stress.     

CX3CR1-fractalkine expression regulates cellular mechanisms involved in adhesion, migration, and survival of human prostate cancer cells

Chemokines and their receptors might be involved in the selection of specific organs by metastatic cancer cells. For instance, the CXCR4-SDF-1alpha pair regulates adhesion and migration of breast as well as prostate cancer cells to metastatic sites. In this study, we present the first evidence for the expression of CX3CR1--the specific receptor for the chemokine fractalkine--by human prostate cancer cells, whereas human bone marrow endothelial cells and differentiated osteoblasts express fractalkine. The adhesion of prostate cancer cells to human bone marrow endothelial cells in flow conditions is significantly reduced by a neutralizing antibody against fractalkine, and they migrate toward a medium conditioned by osteoblasts, which secrete the soluble form of the chemokine. Finally, fractalkine activates the PI3K/Akt survival pathway in human prostate cancer cells.     

CXCR3/CCR5 pathways in metastatic melanoma patients treated with adoptive therapy and interleukin-2

Background:

Adoptive therapy with tumour-infiltrating lymphocytes (TILs) induces durable complete responses (CR) in ∼20% of patients with metastatic melanoma. The recruitment of T cells through CXCR3/CCR5 chemokine ligands is critical for immune-mediated rejection. We postulated that polymorphisms and/or expression of CXCR3/CCR5 in TILs and the expression of their ligands in tumour influence the migration of TILs to tumours and tumour regression.

Methods:

Tumour-infiltrating lymphocytes from 142 metastatic melanoma patients enrolled in adoptive therapy trials were genotyped for CXCR3 rs2280964 and CCR5-Δ32 deletion, which encodes a protein not expressed on the cell surface. Expression of CXCR3/CCR5 in TILs and CXCR3/CCR5 and ligand genes in 113 available parental tumours was also assessed. Tumour-infiltrating lymphocyte data were validated by flow cytometry (N=50).

Results:

The full gene expression/polymorphism model, which includes CXCR3 and CCR5 expression data, CCR5-Δ32 polymorphism data and their interaction, was significantly associated with both CR and overall response (OR; P=0.0009, and P=0.007, respectively). More in detail, the predicted underexpression of both CXCR3 and CCR5 according to gene expression and polymorphism data (protein prediction model, PPM) was associated with response to therapy (odds ratio=6.16 and 2.32, for CR and OR, respectively). Flow cytometric analysis confirmed the PPM. Coordinate upregulation of CXCL9, CXCL10, CXCL11, and CCL5 in pretreatment tumour biopsies was associated with OR.

Conclusion:

Coordinate overexpression of CXCL9, CXCL10, CXCL11, and CCL5 in pretreatment tumours was associated with responsiveness to treatment. Conversely, CCR5-Δ32 polymorphism and CXCR3/CCR5 underexpression influence downregulation of the corresponding receptors in TILs and were associated with likelihood and degree of response.