Silencing of CXCR4 by RNA interference inhibits cell growth and metastasis in human renal cancer cells

Inflammation in Urological Malignancies: The Silent Killer

Several studies have investigated the role of inflammation in promoting tumorigenesis and cancer progression. Neoplastic as well as surrounding stromal and inflammatory cells engage in well-orchestrated reciprocal interactions to establish an inflammatory tumor microenvironment. The tumor-associated inflammatory tissue is highly plastic, capable of continuously modifying its phenotypic and functional characteristics. Accumulating evidence suggests that chronic inflammation plays a critical role in the development of urological cancers. Here, we review the origins of inflammation in urothelial, prostatic, renal, testicular, and penile cancers, focusing on the mechanisms that drive tumor initiation, growth, progression, and metastasis. We also discuss how tumor-associated inflammatory tissue may be a diagnostic marker of clinically significant tumor progression risk and the target for future anti-cancer therapies.

Identification of C3 and FN1 as potential biomarkers associated with progression and prognosis for clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is one of the most lethal urological malignancies, but the pathogenesis and prognosis of ccRCC remain obscure, which need to be better understand.

Methods

Differentially expressed genes were identified and function enrichment analyses were performed using three publicly available ccRCC gene expression profiles downloaded from the Gene Expression Omnibus database. The protein-protein interaction and the competing endogenous RNA (ceRNA) networks were visualized by Cytoscape. Multivariate Cox analysis was used to predict an optimal risk mode, and the survival analysis was performed with the Kaplan-Meier curve and log-rank test. Protein expression data were downloaded from Clinical Proteomic Tumor Analysis Consortium database and Human Protein Atlas database, and the clinical information as well as the corresponding lncRNA and miRNA expression data were obtained via The Cancer Genome Atlas database. The co-expressed genes and potential function of candidate genes were explored using data exacted from the Cancer Cell Line Encyclopedia database.

Results

Of the 1044 differentially expressed genes shared across the three datasets, 461 were upregulated, and 583 were downregulated, which significantly enriched in multiple immunoregulatory-related biological process and tumor-associated pathways, such as HIF-1, PI3K-AKT, P53 and Rap1 signaling pathways. In the most significant module, 36 hub genes were identified and were predominantly enriched in inflammatory response and immune and biotic stimulus pathways. Survival analysis and validation of the hub genes at the mRNA and protein expression levels suggested that these genes, particularly complement component 3 (C3) and fibronectin 1 (FN1), were primarily responsible for ccRCC tumorigenesis and progression. Increased expression of C3 or FN1 was also associated with advanced clinical stage, high pathological grade, and poor survival in patients with ccRCC. Univariate and multivariate Cox regression analysis qualified the expression levels of the two genes as candidate biomarkers for predicting poor survival. FN1 was potentially regulated by miR-429, miR-216b and miR-217, and constructed a bridge to C3 and C3AR1 in the ceRNA network, indicating a critical position of FN1.

Conclusions

The biomarkers C3 and FN1 could provide theoretical support for the development of a novel prognostic tool to advance ccRCC diagnosis and targeted therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08818-0.

The Role of CXCL12 in Kidney Diseases: A Friend or Foe?

Background

Chemokines are a family of proteins mainly mediating the homing and migration of various cells. The CXC chemokine CXCL12 is a member of low-weight-molecular chemokines. In the kidney, CXCL12 is pivotal for renal development and exerts a modulatory effect in kidney diseases under different etiologic settings by binding with CXC chemokine receptor 4 (CXCR4) or CXC chemokine receptor 7 (CXCR7). Besides, CXCL12 also exerts homeostasis influence in diverse physical conditions and various pathological situations. Thus, we conclude the complicated relationship between CXCL12 and kidney diseases in this review.

Summary

In renal development, CXCL12 contributes a lot to nephrogenesis and the formation of renal vasculature via correlating with CXCR4. CXCL12 also plays an essential role in renal recovery from acute kidney injury. However, the CXCL12/CXCR4 axis plays a dual regulatory role in the initiation and development of diabetic kidney disease as well as chronic allogeneic nephropathy after kidney transplantation through dialectical consideration. Additionally, the CXCL12/CXCR4 link is considered as a new risk factor for lupus nephritis and renal cell carcinoma.

Key Messages

Plenty of studies have presented the influence of CXCL12 and the relation with corresponding receptors in diverse biological and pathological statuses. Simultaneously, some drugs and antagonists targeting CXCL12/CXCR4 axis effectively treat various kidney diseases. However, more researches are needed to explore thorough influence and mechanisms, providing more cues for clinical treatments.

Targeting Strategies for Renal Cancer Stem Cell Therapy

Renal cell carcinoma (RCC) is an intractable genitourinary malignancy that accounts for approximately 4% of adult malignancies. Currently, there is no approved targeted therapy for RCC that has yielded durable remissions, and they remain palliative in intent. Emerging evidence has indicated that renal tumorigenesis and RCC treatment-resistance may originate from renal cancer stem cells (CSCs) with tumor-initiating capacity (CSC hypothesis). A better understanding of the mechanism underlying renal CSCs will help to dissect RCC heterogeneity and drug treatment efficiency, to promote more personalized and targeted therapies. In this review, we summarized the stem cell characteristics of renal CSCs. We outlined the targeting strategies and challenges associated with developing therapies that target renal CSCs angiogenesis, immunosuppression, signaling pathways, surface biomarkers, microRNAs and nanomedicine. In conclusion, CSCs are an important role in renal carcinogenesis and represent a valid target for treatment of RCC patients.

CXCL12/CXCR4 signal transduction in diseases and its molecular approaches in targeted-therapy

Chemokines are small molecules called "chemotactic cytokines" and regulate many processes like leukocyte trafficking, homing of immune cells, maturation, cytoskeletal rearrangement, physiology, migration during development, and host immune responses. These proteins bind to their corresponding 7-membrane G-protein-coupled receptors. Chemokines and their receptors are anti-inflammatory factors in autoimmune conditions, so consider as potential targets for neutralization in such diseases. They also express by cancer cells and function as angiogenic factors, and/or survival/growth factors that enhance tumor angiogenesis and development. Among chemokines, the CXCL12/CXCR4 axis has significantly been studied in numerous cancers and autoimmune diseases. CXCL12 is a homeostatic chemokine, which is acts as an anti-inflammatory chemokine during autoimmune inflammatory responses. In cancer cells, CXCL12 acts as an angiogenic, proliferative agent and regulates tumor cell apoptosis as well. CXCR4 has a role in leukocyte chemotaxis in inflammatory situations in numerous autoimmune diseases, as well as the high levels of CXCR4, observed in different types of human cancers. These findings suggest CXCL12/CXCR4 as a potential therapeutic target for therapy of autoimmune diseases and open a new approach to targeted-therapy of cancers by neutralizing CXCL12 and CXCR4. In this paper, we reviewed the current understanding of the role of the CXCL12/CXCR4 axis in disease pathology and cancer biology, and discuss its therapeutic implications in cancer and diseases.

Clinicopathological and prognostic significance of CXCR4 high expression in renal cell carcinoma: A meta-analysis and literature review

INTRODUCTION

Previous results have indicated that CXCR4 is an oncogene in several types of human tumors including renal cell carcinoma (RCC). However, the correlation between CXCR4 expression and clinicopathological characteristics of RCC remains unclear.

MATERIALS AND METHODS

We conducted a meta-analysis to quantitatively evaluate the association of CXCR4 expression with the incidence of RCC and clinicopathological characteristics. Final analysis of 1203 patients with RCC from 14 eligible studies was performed.

RESULTS

We observed that CXCR4 expression is significantly higher in RCC than in normal renal tissue, and the pooled OR from 7 studies including 435 RCC and 297 normal renal tissues was OR = 46.23, 95% CI = 7.18-297.69, p < 0.0001. CXCR4 expression is not associated with gender status and clinical stages. However, CXCR4 expression was significantly associated with pathological grades, metastatic status, and overall survival in patients with RCC.

DISCUSSION

These results indicate that CXCR4 expression is associated with increased risk, progression, and prognosis for patients with RCC. The determination of CXCR4 expression may provide a biomarker for tumor risk evaluation, progression, and prognosis of patients with RCC.

Impaired Th17 cell proliferation and decreased pro-inflammatory cytokine production in CXCR3/CXCR4 double-deficient mice of vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is a common observed infection, affecting approximately 75% of women of reproductive age. Drug resistance represents a troublesome stumbling block associated with VVC therapy. Thus the aim of the present study was to provide information regarding the selection of potential drug targets for VVC. CXCR3-, CXCR4-, or CXCR/CXCR4 double-deficient mouse models of VVC were subsequently established, with changes to the load of Candida Albicans evaluated accordingly. The biological behaviors of the vaginal epithelial cells were characterized in response to the CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout in vivo. Our initial observations revealed that in mice with VVC, CXCR3-, CXCR4-, or CXCR3 - CXCR4 double-knockout resulted in a decreased load of C. Albicans as well as reduced levels and proportion of Th17 cells. Proinflammatory cytokine production was found to be inhibited by CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout whereby the mRNA and protein expressions CXCR3, CXCR4, IL-17, IL-6, and TNF-α exhibited decreased levels. CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout appeared to function as positive proliferation factors, while playing a negative role in the processes of apoptosis and the cell cycle of vaginal epithelial cells. Taken together, the key findings of the study suggested that CXCR3/CXCR4 double-knockout could act to hinder the progression of VVC, highlighting its promise as a novel therapeutic target in the treatment of VVC. CXCR3 and CXCR4 genes may regulate Th17/IL-17 immune inflammatory pathways to participate in antifungal immunity.

Pathological roles of the homeostatic chemokine CXCL12

CXCL12 is a CXC chemokine that traditionally has been classified as a homeostatic chemokine. It contributes to physiological processes such as embryogenesis, hematopoiesis and angiogenesis. In contrast to these homeostatic functions, increased expression of CXCL12 in general, or of a specific CXCL12 splicing variant has been demonstrated in various pathologies. In addition to this increased or differential transcription of CXCL12, also upregulation of its receptors CXC chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3 (ACKR3) contributes to the onset or progression of diseases. Moreover, posttranslational modification of CXCL12 during disease progression, through interaction with locally produced molecules or enzymes, also affects CXCL12 activity, adding further complexity. As CXCL12, CXCR4 and ACKR3 are broadly expressed, the number of pathologies wherein CXCL12 is involved is growing. In this review, the role of the CXCL12/CXCR4/ACKR3 axis will be discussed for the most prevalent pathologies. Administration of CXCL12-neutralizing antibodies or small-molecule antagonists of CXCR4 or ACKR3 delays disease onset or prevents disease progression in cancer, viral infections, inflammatory bowel diseases, rheumatoid arthritis and osteoarthritis, asthma and acute lung injury, amyotrophic lateral sclerosis and WHIM syndrome. On the other hand, CXCL12 has protective properties in Alzheimer's disease and multiple sclerosis, has a beneficial role in wound healing and has crucial homeostatic properties in general.

Development of a novel 99m Tc-labeled small molecular antagonist for CXCR4 positive tumor imaging

The chemokine receptor 4 (CXCR4) has been an attractive molecular target for tumor imaging, because it is overexpressed in many tumor types and involved in tumor progression and metastasis. The purpose of this study is to examine the CXCR4 targeting properties of ^99m Tc-labeled AMD3465, a small molecule antagonist of CXCR4. ^99m Tc-AMD3465 was prepared in high yield (>95%) and stable in mice serum at least for 4 hours. In vitro cell binding experiments were performed with Chinese hamster ovary (CHO), MCF-7 (breast cancer), and CHO-CXCR4 (CHO stably transfected to express CXCR4) cell lines. Small animal single photon emission computed tomography/computed tomography imaging studies in nude mice bearing MCF-7 and CHO xenografts showed that the uptakes of the radiotracer in MCF-7 tumors were significantly higher than those in the CXCR4-negative CHO tumors (P < 0.05), and the MCF-7 tumors uptake could be blocked with an excess of unlabeled AMD3465 (P < 0.05). These results suggested that ^99m Tc-AMD3465 could be a potential single photon emission computed tomography radiotracer for CXCR4 imaging.

MicroRNA-126 inhibits colon cancer cell proliferation and invasion by targeting the chemokine (C-X-C motif) receptor 4 and Ras homolog gene family, member A, signaling pathway

MicroRNA-126 (miR-126) suppresses the migration, proliferation and invasion of colon cancer cells. However, the underlying mechanisms of miR-126 in colon cancer have not been fully elucidated. In this study, in vivo experiments revealed that miR-126 inhibits colon cancer growth and metastasis. Furthermore, miR-126 was down-regulated in human colon cancer tissue, and its expression was inversely correlated with TNM stage and metastasis of patients. Low level of miR-126 identified patients with poor prognosis. And we found that miR-126 expression was negatively correlated with the expression levels of chemokine (C-X-C motif) receptor 4 (CXCR4) and components of signaling pathway of Ras homolog gene family, member A (RhoA) in vitro and in vivo. Moreover, we verified that miR-126 negatively regulated CXCR4 and RhoA signaling in vitro. In addition, either in miR-126-overexpressing or in miR- 126-silenced colon cancer cells, the restoration of CXCR4 could significantly reverse the proliferation and invasion, as well as abolish the effects of miR-126 on RhoA signaling pathway. Collectively, these results demonstrated that miR-126 acts as a tumor suppressor by inactivating RhoA signaling via CXCR4 in colon cancer. And miR-126 may serve as a prognostic marker for monitoring and treating colon cancer.

Versican Promotes Tumor Progression, Metastasis and Predicts Poor Prognosis in Renal Carcinoma

The proteoglycan versican (VCAN) promotes tumor progression and enhances metastasis in several cancers; however, its role in clear cell renal cell carcinoma (ccRCC) remains unknown. Recent evidence suggests that VCAN is an important target of chromosomal 5q gain, one of the most prevalent genetic abnormalities in ccRCC. Thus, we investigated whether VCAN expression is associated with the pathogenesis of ccRCC. VCAN expression was analyzed using three RCC and normal kidney cell lines as well as a clinical cohort of 84 matched ccRCC and normal renal tissues. Functional analyses on growth and progression properties were performed using VCAN-depleted ccRCC cells. Microarray expression profiling was employed to investigate the target genes and biologic pathways involved in VCAN-mediated ccRCC carcinogenesis. ccRCC had elevated VCAN expression in comparison with normal kidney in both cell lines and clinical specimens. The elevated expression of VCAN was significantly correlated with metastasis (P < 0.001) and worse 5-year overall survival after radical nephrectomy (P = 0.014). In vitro, VCAN knockdown significantly decreased cell proliferation and increased apoptosis in Caki-2 and 786-O cells, and this was associated with alteration of several TNF signaling-related genes such as TNFα, BID, and BAK Furthermore, VCAN depletion markedly decreased cell migration and invasion which correlated with reduction of MMP7 and CXCR4. These results demonstrate that VCAN promotes ccRCC tumorigenesis and metastasis and thus is an attractive target for novel diagnostic, prognostic, and therapeutic strategies.Implications: This study highlights the oncogenic role of VCAN in renal cell carcinogenesis and suggests that this gene has therapeutic and/or biomarker potential for renal cell cancer. Mol Cancer Res; 15(7); 884-95. ©2017 AACR.

Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rationale for therapies targeting this aggressive cell population. Precise identification of renal CSC populations and the complete cell hierarchy will accurately inform characterization of disease subtypes. This will ultimately contribute to more personalized and targeted therapies. Here, we summarize potential targeting strategies for renal cancer cells and renal CSCs, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors (mTOR), interleukins, CSC marker inhibitors, bone morphogenetic protein-2, antibody drug conjugates, and nanomedicine. In conclusion, targeting therapies for RCC represent new directions for exploration and clinical investigation and they plant a seed of hope for advanced clinical care.

CXCR4 pharmacogical inhibition reduces bone and soft tissue metastatic burden by affecting tumor growth and tumorigenic potential in prostate cancer preclinical models

BACKGROUND

The majority of prostate cancer (Pca) patient morbidity can be attributed to bone metastatic events, which poses a significant clinical obstacle. Therefore, a better understanding of this phenomenon is imperative and might help to develop novel therapeutic strategies. Stromal cell-derived factor 1α (SDF-1α) and its receptor CXCR4 have been implicated as regulators of bone resorption and bone metastatic development, suggesting that agents able to suppress this signaling pathway may be used as pharmacological treatments. In this study we studied if two CXCR4 receptor antagonists, Plerixafor and CTE9908, may affect bone metastatic disease induced by Pca in preclinical experimental models

METHODS

To verify the hypothesis that CXCR4 inhibition affects Pca metastatic disease, selective CXCR4 compounds, Plerixafor, and CTE9908, were tested in preclinical models known to generate bone lesions. Additionally, the expression levels of CXCR4 and SDF-1α were analyzed in a number of human tissues derived from primary tumors, lymph-nodes and osseous metastases of Pca as well as in a wide panel of human Pca cell lines to non-tumorigenic and tumorigenic phenotype.

RESULTS

Bone-derived Pca cells express higher CXCR4 levels than other Pca cell lines. This differential expression was also observed in human Pca samples. In vitro evidence supports the hypothesis that factors produced by bone microenvironment differentially sustain CXCR4 and SDF1-α expression with respect to prostate microenvironment determining increased efficacy toward Plerixafor. The use of SDF1-α neutralizing antibodies greatly reduced the increase of CXCR4 expression in cells co-cultured with bone stromal cells (BMSc) and to a lesser extent in cells co-cultured with prostate stromal cells (HPSc) and partially reduced SDF1-α Plerixafor efficacy. SDF-1α induced tumor cell migration and invasion, as well as MMP-9, MMP-2, and uPA expression, which were reduced by Plerixafor. The incidence of X-ray detectable bone lesions was significantly reduced following Plerixafor and CTE9908 treatment Kaplan-Meier probability plots showed a significant improvement in the overall survival of mice treated with Plerixafor and CTE9908. The reduced intra-osseous growth of PC3 and PCb2 tumor cells after intratibial injection, as a result of Plerixafor and CTE9908 treatment, correlated with decreased osteolysis and serum levels of both mTRAP and type I collagen fragments (CTX), which were significantly lower with respect to controls.

CONCLUSIONS

Our report provides novel information on the potential activity of CXCR4 inhibitors on the formation and progression of Pca bone and soft tissue metastases and supports a biological rationale for the use of these inhibitors in men at high risk to develop clinically evident bone lesions.

A meta-analysis for CXCR4 as a prognostic marker and potential drug target in non-small cell lung cancer

Background

Recent reports have shown that C-X-C chemokine receptor type 4 (CXCR4) is a candidate oncogene in several types of human tumors, including non-small cell lung cancer (NSCLC). However, the correlation between CXCR4 expression and clinicopathological characteristics of NSCLC remains controversial and has not been emphasized. The aim of this study is to quantitatively evaluate the association of CXCR4 expression with the incidence of NSCLC and clinicopathological characteristics by performing a meta-analysis.

Methods

A detailed literature search was carried out for related research publications. Only articles in which CXCR4 expression was detected by immunohistochemical staining were included. Odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) were calculated and summarized.

Results

Final analysis of 1,872 NSCLC patients from 19 eligible studies was performed. We observed that CXCR4 expression was significantly higher in NSCLC than in normal lung tissue, based on the pooled OR from ten studies, including 678 NSCLCs and 189 normal lung tissues (OR =16.66, 95% CI =6.94–40.02, P<0.00001). CXCR4 expression was also significantly associated with clinical stages, metastatic status, and overall survival (OS) in NSCLC patients. In addition, CXCR4 mRNA high expression was found to correlate with worse OS of all NSCLC patients followed for 20 years, HR =1.24, P=0.0047.

Conclusion

The present meta-analysis indicated that CXCR4 protein expression is associated with an increased risk and worse survival in NSCLC patients. The aberrant CXCR4 protein and mRNA expression play an important role in the carcinogenesis and metastasis of NSCLC.

The intricate role of CXCR4 in cancer

Chemokines mediate numerous physiological and pathological processes related primarily to cell homing and migration. The chemokine CXCL12, also known as stromal cell-derived factor-1, binds the G-protein-coupled receptor CXCR4, which, through multiple divergent pathways, leads to chemotaxis, enhanced intracellular calcium, cell adhesion, survival, proliferation, and gene transcription. CXCR4, initially discovered for its involvement in HIV entry and leukocytes trafficking, is overexpressed in more than 23 human cancers. Cancer cell CXCR4 overexpression contributes to tumor growth, invasion, angiogenesis, metastasis, relapse, and therapeutic resistance. CXCR4 antagonism has been shown to disrupt tumor-stromal interactions, sensitize cancer cells to cytotoxic drugs, and reduce tumor growth and metastatic burden. As such, CXCR4 is a target not only for therapeutic intervention but also for noninvasive monitoring of disease progression and therapeutic guidance. This review provides a comprehensive overview of the biological involvement of CXCR4 in human cancers, the current status of CXCR4-based therapeutic approaches, as well as recent advances in noninvasive imaging of CXCR4 expression.

Clinicopathological significance of CXCR4 in non-small cell lung cancer

Background

Emerging evidence indicates that C-X-C chemokine receptor type 4 (CXCR4) is a candidate oncogene in several types of human tumors including non-small cell lung cancer (NSCLC). However, the correlation between CXCR4 expression and clinicopathological characteristics of NSCLC remains unclear. Here, we conducted a meta-analysis to quantitatively evaluate the association of CXCR4 expression with the incidence of NSCLC and clinicopatho-logical characteristics.

Methods

A detailed literature search was made from Medline and Web of Science for related research publications written in English and Chinese. The methodological quality of the studies was also evaluated. Analyses of pooled data were performed. Odds ratio (OR) and hazard ratio (HR) were calculated and summarized.

Results

The final analysis of 1,446 NSCLC patients from 13 eligible studies was performed. We observed that CXCR4 expression was significantly higher in NSCLC than in normal lung tissue from the pooled OR from five studies including 380 NSCLC and 118 normal lung tissue (OR=12.86, 95% confidence interval =3.63–45.59, P<0.0001). CXCR4 expression was not associated with smoking status and type of pathology. However, CXCR4 expression was significantly associated with clinical stages, metastatic status, and overall survival in NSCLC patients.

Conclusion

The results of this meta-analysis suggest that CXCR4 expression is associated with an increased risk and worse survival in NSCLC patients. The aberrant CXCR4 expression plays an important role in the carcinogenesis and metastasis of NSCLC.

Clinicopathological significance of CXCR4 expression in renal cell carcinoma: a meta-analysis

BACKGROUND

Emerging evidence indicates that C-X-C chemokine receptor type 4 (CXCR4) is a candidate oncogene in several types of human tumors including renal cell carcinoma (RCC). We conducted a meta-analysis to quantitatively evaluate the association of CXCR4 expression with the incidence of RCC and clinicopathological characteristics.

METHODS

We searched PubMed, Embase, and ISI Web of Knowledge to identify studies written in English. Methodological quality of the studies was also evaluated. Odds ratio and hazard ratio were calculated and summarized.

RESULTS

Final analysis was performed of 994 RCC patients from 11 eligible studies. We observed that CXCR4 expression was significantly higher in RCC than in normal renal tissues. CXCR4 expression was not found to be associated with sex status or clinical staging. However, CXCR4 expression was clearly associated with Fuhrman grading, metastatic status, and overall survival in RCC patients.

CONCLUSIONS

The results of this meta-analysis suggest that CXCR4 expression is associated with an increased risk and worsen survival in RCC patients. The aberrant CXCR4 expression plays an important role in the carcinogenesis and metastasis of RCC.

Overexpression of CXCR4 is significantly associated with cisplatin-based chemotherapy resistance and can be a prognostic factor in epithelial ovarian cancer

The chemokine receptor 4 (CXCR4) plays an important role in the growth, angiogenesis and metastasis of various cancers, including epithelial ovarian cancer (EOC). However, the correlation between CXCR4 and the clinical response of EOC patients to chemotherapy remains unknown. 124 EOC patients were recruited to assess the relationship between CXCR4 and the response to cisplatin-based chemotherapy. The results showed that patients with a higher CXCR4 expression had a significantly lower chemosensitivity, a poorer progression-free survival and a lower overall survival than those with lower CXCR4 expression. In addition, knockdown of CXCR4 by small interfering RNA suppressed cell proliferation and resulted in G1/S arrest, increased apoptosis and chemosensitivity in both cisplatin-sensitive A2780 cells and cisplatin-resistant cell A2780/cis in vitro. Our data suggest that CXCR4 is one of the key molecules in cisplatin-based chemotherapy for EOC patients and that CXCR4 inhibition is a potential strategy to address the chemoresistance of EOC. [BMB Reports 2014; 47(1): 33-38]

The influence of lentivirus-mediated CXCR4 RNA interference on hepatic metastasis of colorectal cancer

The aim of this study was to construct a lentiviral vector of CXCR4-siRNA (Lenti-CXCR4-siRNA) and investigate whether the vector can inhibit the growth, migration, invasion and hepatic metastasis of colorectal cancer (CRC). RT-PCR and western blotting were employed to identify the ideal RNA interference sequence. Lenti-CXCR4-siRNA was constructed and transfected into the SW480 cell line. We used RT-PCR and western blotting to measure the expression of CXCR4 RNA and protein, respectively; the MTS assay to assess the proliferation of SW480 cells; transwell chambers to estimate the inhibitory effect on migration and invasion; and the Balb/c nude mouse model of CRC to examine the inhibition of hepatic metastasis. The relative expression of the CXCR4 gene and protein was 5.4 and 18.95%, respectively, in the siCXCR4 group. The genes in the expression plasmid pLenti-CXCR4-siRNA were in the correct order. In the SW480, nonsense control (NC) and the Lenti-CXCR4-siRNA groups CXCR4 RNA levels were, respectively, 0.54±0.06, 1.00±0.03 and 0.11±0.04 (P=0.0001); CXCR4 protein levels were 0.60±0.03, 0.72±0.03 and 0.18±0.02 (P=0.0001); the OD value was 1.38±0.04 (P=0.0050), 1.28±0.05 (P=0.0256) and 0.92±0.06; SW480 cell number in migration test was 32±6.85, 32.63±1.69 and 0.75±0.71 (P=0.0000); SW480 cell number in the invasion test was 29.13±10.3, 30.38±6.09 and 0.63±0.74 (P=0.0000); hepatic metastasis number was 7.10±3.98 (P=0.034), 7.50±4.09 (P=0.019) and (3.50±2.51); hepatic metastasis mean weight (in g) was 2.25±2.51 (P=0.000), 2.11±2.38 (P=0.000) and 1.45±2.07. Lenti-CXCR4-siRNA constructs were correctly constructed and effectively inhibit the expression of CXCR4 RNA and protein, reducing the proliferation, migration, invasion capacity of SW480 cells and hepatic metastasis of CRC.

Antitumour activity of the recombination polypeptide GST-NT21MP is mediated by inhibition of CXCR4 pathway in breast cancer

BACKGROUND

CXC chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1α (SDF-1α, also known as CXCL12) have important roles in promoting tumour growth and metastasis. Therefore, targeting CXCR4 could be a promising strategy for treatment of human cancer.

METHODS

To achieve this goal, we developed a highly purified recombination polypeptide (GST-NT21MP), which is a synthetic 21-mer peptide antagonist of CXCR4 (NT21MP) derived from the viral macrophage inflammatory protein II by fermentation technology, affinity chromatography and fast protein liquid chromatography. In this study, we used multiple methods such as MTT assay, FACS, invasion assay, RT-PCR and western blot to explore the efficacy and mechanism by which GST-NT21MP inhibits cell growth, migration and invasion of breast cancer in vitro and in vivo.

RESULTS

We found that blockade of CXCR4 pathway by GST-NT21MP decreased SDF-1-induced cell growth, adhesion and migration capacities in breast cancer cells. Moreover, GST-NT21MP significantly retarded pulmonary metastasis in vivo. Furthermore, GST-NT21MP-mediated antitumour activity was found to be associated with reduced phosphorylated Src, Akt, FAK and ERK1/2 as well as decreased Bcl-2.

CONCLUSIONS

Our results suggest that GST-NT21MP could be a potential anticancer agent for the treatment of breast cancer.

The signaling pathway of stromal cell-derived factor-1 and its role in kidney diseases

The chemokine stromal cell-derived factor-1 (SDF-1) regulates the trafficking of progenitor cell (PGC) during embryonic development, cell chemotaxis, and postnatal homing into injury sites. SDF-1 also regulates cell growth, survival, adhesion and angiogenesis. However, in different tissues/cells, the role of SDF-1 is different, such as that it is increased in most of the tumors and associated with cancer metastasis, whereas it is essential for the development of vasculature. For kidney diseases, its role remains controversial. Signaling pathways might be very important in the pathogenesis of kidney diseases. We performed this review to provide a relatively complete signaling pathway flowchart for SDF-1 to the investigators who were interested in the role of SDF-1 in the pathogenesis of kidney diseases. Here, we reviewed the signal transduction pathway of SDF-1 and its role in the pathogenesis of kidney diseases.

Structural guided scaffold phage display libraries as a source of bio-therapeutics

We have developed a structurally-guided scaffold phage display strategy for identification of ligand mimetic bio-therapeutics. As a proof of concept we used the ligand of integrin αvβ6, a tumour cell surface receptor and a major new target for imaging and therapy of many types of solid cancer. NMR structure analysis showed that RGD-helix structures are optimal for αvβ6 ligand-interaction, so we designed novel algorithms to generate human single chain fragment variable (scFv) libraries with synthetic V_H-CDR3 encoding RGD-helix hairpins with helices of differing pitch, length and amino acid composition. Study of the lead scFv clones D25scFv and D34scFv and their corresponding V_H-CDR3 derived peptides, D25p and D34p, demonstrated: specific binding to recombinant and cellular αvβ6; inhibition of αvβ6-dependent cell and ligand adhesion, αvβ6-dependent cell internalisation; and selective retention by αvβ6-expressing, but not αvβ6-negative, human xenografts. NMR analysis established that both the D25p and D34p retained RGD-helix structures confirming the success of the algorithm. In conclusion, scFv libraries can be engineered based on ligand structural motifs to increase the likelihood of developing powerful bio-therapeutics.