CCR7 regulates Twist to induce the epithelial-mesenchymal transition in pancreatic ductal adenocarcinoma

Immune Cell Migration to Cancer

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

A Mouse Model of Damp-Heat Syndrome in Traditional Chinese Medicine and Its Impact on Pancreatic Tumor Growth

Background

Damp-heat syndrome is one of the most important syndrome types in the traditional Chinese medicine (TCM) syndrome differentiation and treatment system, as well as the core pathogenesis of pancreatic cancer (PC) which remains a challenge to medical researchers due to its insidious onset and poor prognosis. Great attention has been given to the impact of damp-heat syndrome on tumorigenesis and progression, but less attention has been given to damp-heat modeling per se. Studying PC in a proper damp-heat syndrome animal model can recapitulate the actual pathological process and contribute to treatment strategy improvement.

Methods

Here, an optimized damp-heat syndrome mouse model was established based on our prior experience. The Fibonacci method was applied to determine the maximum tolerated dosage of alcohol for mice. Damp-heat syndrome modeling with the old and new methods was performed in parallel of comparative study about general appearance, food intake, water consumption and survival. Major organs, including the liver, kidneys, lungs, pancreas, spleen, intestines and testes, were collected for histological evaluation. Complete blood counts and biochemical tests were conducted to characterize changes in blood circulation. PC cells were subcutaneously inoculated into mice with damp-heat syndrome to explore the impact of damp-heat syndrome on PC growth. Hematoxylin-eosin staining, Masson staining and immunohistochemistry were performed for pathological evaluation. A chemokine microarray was applied to screen the cytokines mediating the proliferation-promoting effects of damp-heat syndrome, and quantitative polymerase chain reaction and Western blotting were conducted for results validation.

Results

The new modeling method has the advantages of mouse-friendly features, easily accessible materials, simple operation, and good stability. More importantly, a set of systematic indicators was proposed for model evaluation. The new modeling method verified the pancreatic tumor-promoting role of damp-heat syndrome. Damp-heat syndrome induced the proliferation of cancer-associated fibroblasts and promoted desmoplasia. In addition, circulating and tumor-located chemokine levels were altered by damp-heat syndrome, characterized by tumor promotion and immune suppression.

Conclusions

This study established a stable and reproducible murine model of damp-heat syndrome in TCM with systematic evaluation methods. Cancer associated fibroblast-mediated desmoplasia and chemokine production contribute to the tumor-promoting effect of damp-heat syndrome on PC.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

Does CCL19 act as a double-edged sword in cancer development?

Cancer is considered a life-threatening disease, and several factors are involved in its development. Chemokines are small proteins that physiologically exert pivotal roles in lymphoid and non-lymphoid tissues. The imbalance or dysregulation of chemokines has contributed to the development of several diseases, especially cancer. CCL19 is one of the homeostatic chemokines that is abundantly expressed in the thymus and lymph nodes. This chemokine, which primarily regulates immune cell trafficking, is involved in cancer development. Through the induction of anti-tumor immune responses and inhibition of angiogenesis, CCL19 exerts tumor-suppressive functions. In contrast, CCL19 also acts as a tumor-supportive factor by inducing inflammation, cell growth, and metastasis. Moreover, CCL19 dysregulation in several cancers, including colorectal, breast, pancreatic, and lung cancers, has been considered a tumor biomarker for diagnosis and prognosis. Using CCL19-based therapeutic approaches has also been proposed to overcome cancer development. This review will shed more light on the multifarious function of CCL19 in cancer and elucidate its application in diagnosis, prognosis, and even therapy. It is expected that the study of CCL19 in cancer might be promising to broaden our knowledge of cancer development and might introduce novel approaches in cancer management.

Fucoxanthin Prevents Pancreatic Tumorigenesis in C57BL/6J Mice That Received Allogenic and Orthotopic Transplants of Cancer Cells

Fucoxanthin (Fx) is a marine carotenoid with anti-inflammatory and anti-cancer properties in various animal models of carcinogenesis. However, there is currently no information on the effects of Fx in animal models of pancreatic cancer. We investigated the chemopreventive effects of Fx in C57BL/6J mice that received allogenic and orthotopic transplantations of cancer cells (KMPC44) derived from a pancreatic cancer murine model (Ptf1aCre/+; LSL-krasG12D/+). Using microarray, immunofluorescence, western blot, and siRNA analyses, alterations in cancer-related genes and protein expression were evaluated in pancreatic tumors of Fx-administered mice. Fx administration prevented the adenocarcinoma (ADC) development of pancreatic and parietal peritoneum tissues in a pancreatic cancer murine model, but not the incidence of ADC. Gene and protein expressions showed that the suppression of chemokine (C-C motif) ligand 21 (CCL21)/chemokine receptor 7 (CCR7) axis, its downstream of Rho A, B- and T-lymphocyte attenuator (BTLA), N-cadherin, αSMA, pFAK(Tyr397), and pPaxillin(Tyr31) were significantly suppressed in the pancreatic tumors of mice treated with Fx. In addition, Ccr7 knockdown significantly attenuated the growth of KMPC44 cells. These results suggest that Fx is a promising candidate for pancreatic cancer chemoprevention that mediates the suppression of the CCL21/CCR7 axis, BTLA, tumor microenvironment, epithelial mesenchymal transition, and adhesion.

CCR7 as a therapeutic target in Cancer

The CCR7 chemokine axis is comprised of chemokine ligand 21 (CCL21) and chemokine ligand 19 (CCL19) acting on chemokine receptor 7 (CCR7). This axis plays two important but apparently opposing roles in cancer. On the one hand, this axis is significantly engaged in the trafficking of a number of effecter cells involved in mounting an immune response to a growing tumour. This suggests therapeutic strategies which involve potentiation of this axis can be used to combat the spread of cancer. On the other hand, the CCR7 axis plays a significant role in controlling the migration of tumour cells towards the lymphatic system and metastasis and can thus contribute to the expansion of cancer. This implies that therapeutic strategies which involve decreasing signaling through the CCR7 axis would have a beneficial effect in preventing dissemination of cancer. This dichotomy has partly been the reason why this axis has not yet been exploited, as other chemokine axes have, as a therapeutic target in cancer. Recent report of a crystal structure for CCR7 provides opportunities to exploit this axis in developing new cancer therapies. However, it remains unclear which of these two strategies, potentiation or antagonism of the CCR7 axis, is more appropriate for cancer therapy. This review brings together the evidence supporting both roles of the CCR7 axis in cancer and examines the future potential of each of the two different therapeutic approaches involving the CCR7 axis in cancer.

CCR9 and CCL25: A review of their roles in tumor promotion

Chemokines constitute a superfamily of small chemotactic cytokines with functions that are based on interactions with their corresponding receptors. It has been found that, among other functions, chemokines regulate the migratory and invasive abilities of cancer cells. Multiple studies have confirmed that chemokine receptor 9 (CCR9) and its exclusive ligand, chemokine 25 (CCL25), are overexpressed in a variety of malignant tumors and are closely associated with tumor proliferation, apoptosis, invasion, migration and drug resistance. This review evaluates recent advances in understanding the role of CCR9/CCL25 in cancer development. First, we outline the general background of chemokines in cancer and the structure and function of CCR9 and CCL25. Next, we describe the basic function of CCR9/CCL25 in the cancer process. Then, we introduce the role of CCR9/CCL25 and related signaling pathways in various cancers. Finally, future research directions are proposed. In general, this paper is intended to serve as a comprehensive repository of information on this topic and is expected to contribute to the design of other research projects and future efforts to develop treatment strategies for ameliorating the effects of CCR9/CCL25 in cancer.

Chemokines and their Receptors: Multifaceted Roles in Cancer Progression and Potential Value as Cancer Prognostic Markers

Chemokines are chemotactic cytokines that mediate immune cell chemotaxis and lymphoid tissue development. Recent advances have indicated that chemokines and their cognate receptors play critical roles in cancer-related inflammation and cancer progression. On the basis of these findings, the chemokine system has become a new potential drug target for cancer immunotherapy. In this review, we summarize the essential roles of the complex network of chemokines and their receptors in cancer progression. Furthermore, we discuss the potential value of the chemokine system as a cancer prognostic marker. The chemokine system regulates the infiltration of immune cells into the tumor microenvironment, which induces both pro- and anti-immunity and promotes or suppresses tumor growth and proliferation, angiogenesis, and metastasis. Increasing evidence indicates the promising prognostic value of the chemokine system in cancer patients. While CCL2, CXCL10, and CX3CL1/CX3CR1 can serve as favorable or unfavorable prognostic factors depending on the cancer types, CCL14 and XCL1 possess good prognostic value. Other chemokines such as CXCL1, CXCL8, and CXCL12 are poor prognostic markers. Despite vast advances in our understanding of the complex nature of the chemokine system in tumor biology, knowledge about the multifaceted roles of the chemokine system in different types of cancers is still limited. Further studies are necessary to decipher distinct roles within the chemokine system in terms of cancer progression and to validate their potential value in cancer prognosis.

Clinical significance and prospective molecular mechanism of C‑C motif chemokine receptors in patients with early‑stage pancreatic ductal adenocarcinoma after pancreaticoduodenectomy

The present study aimed to determine the clinical significance and potential molecular mechanisms of C‑C motif chemokine receptor (CCR) genes in patients with early‑stage pancreatic ductal adenocarcinoma (PDAC). The transcriptomic, survival and clinical data of 112 patients with early‑stage PDAC who underwent pancreaticoduodenectomy were obtained from The Cancer Genome Atlas. The prognostic values of the CCR genes involved in early‑stage PDAC were evaluated using Kaplan‑Meier analysis and the multivariate Cox proportional risk regression model, and the potential molecular mechanisms were determined using bioinformatics tools. The identified CCRs closely interacted with each other at both the gene and protein levels. High expression levels of CCR5 [adjusted P=0.012; adjusted hazard ration (HR)=0.478, 95% confidence interval (CI)=0.269‑0.852], CCR6 (adjusted P=0.026; adjusted HR=0.527, 95% CI=0.299‑0.927) and CCR9 (adjusted P=0.001; adjusted HR=0.374, 95% CI=0.209‑0.670) were significantly associated with longer overall survival times in patients with early‑stage PDAC. The contribution of CCR5, CCR6 and CCR9 to the outcome of early‑stage PDAC was also demonstrated. Combined survival analysis of CCR5, CCR6 and CCR9 suggested that patients with high expression levels of these CCRs exhibited the most favorable outcomes. A prognostic signature was constructed in terms of the expression level of CC5, CCR6 and CCR9, and time‑dependent receiver operating characteristic curves indicated that this signature was able to effectively predict the outcome of patients with early‑stage PDAC. The potential molecular mechanisms of CCR5, CC6 and CCR9 in PDAC include its intersection of the P53, nuclear factor (NF)‑κB, generic transcription, mitogen‑activated protein kinase and STAT signaling pathways. Collectively, this highlights that CCR5, CCR6 and CCR9 are potential prognostic biomarkers for early‑stage PDAC.

Dual reporter genetic mouse models of pancreatic cancer identify an epithelial-to-mesenchymal transition-independent metastasis program

Epithelial‐to‐mesenchymal transition (EMT) is a recognized eukaryotic cell differentiation program that is also observed in association with invasive tumors. Partial EMT program in carcinomas imparts cancer cells with mesenchymal‐like features and is proposed as essential for metastasis. Precise determination of the frequency of partial EMT program in cancer cells in tumors and its functional role in metastases needs unraveling. Here, we employed mesenchymal cell reporter mice driven by αSMA‐Cre and Fsp1‐Cre with genetically engineered mice that develop spontaneous pancreatic ductal adenocarcinoma (PDAC) to monitor partial EMT program. Both αSMA‐ and Fsp1‐Cre‐mediated partial EMT programs were observed in the primary tumors. The established metastases were primarily composed of cancer cells without evidence for a partial EMT program, as assessed by our fate mapping approach. In contrast, metastatic cancer cells exhibiting a partial EMT program were restricted to isolated single cancer cells or micrometastases (3–5 cancer cells). Collectively, our studies identify large metastatic nodules with preserved epithelial phenotype and potentially unravel a novel metastasis program in PDAC.

Meta-analysis of the prognostic value of C-C chemokine receptor type 7 in patients with solid tumors

Background

Expression of C-C chemokine receptor type 7 (CCR7) is associated with the prognosis of several cancers. The aim of this study was to conduct the meta-analysis to determine the prognostic value of CCR7 expression in solid tumors.

Materials and methods

We searched for relevant literature in the PubMed, Embase, and Cochrane Library databases (last updated on January 15, 2018). The associations of CCR7 expression with overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), progress-free survival (PFS), and disease-specific survival (DSS) were estimated.

Results

In total, 30 qualified studies including 3,413 patients were enrolled. The results revealed that higher expression of CCR7 predicted poorer OS (pooled HR =1.79; 95% CI =1.49–2.16; P<0.001) and PFS (pooled HR =2.18; 95% CI =1.49–3.18; P<0.001), but was not associated with DFS (pooled HR =1.69; 95% CI =0.79–3.61; P=0.175), RFS (pooled HR =1.29; 95% CI =0.48–3.44; P=0.618), or DSS (pooled HR =3.06; 95% CI =0.38–24.83; P<0.294).

Conclusion

From this meta-analysis, we concluded that high expression of CCR7 in tumor tissue is associated with poor survival in patients with solid tumors, and may be a prognostic biomarker for tumor progression.

Expression of Epithelial-Mesenchymal Transition Proteins in Pancreatic Anaplastic (Undifferentiated) Carcinoma

OBJECTIVES

The aim of this study was to identify an association of pancreatic anaplastic carcinoma (APC) with the epithelial-mesenchymal transition (EMT).

METHODS

Resected APCs (n = 24) were examined to assess components of APCs, including carcinomatous, transitional, and sarcomatous regions. Analysis was performed based on the immunoreactivity of E-cadherin and 3 EMT-related proteins: Slug (zinc finger protein SNAI2), Twist (Twist-related protein 1), and Zeb1 (zinc finger E-box-binding homeobox 1). Expression score was determined based on staining intensity and stained area of the target cells. Finally, we performed a hierarchical clustering based on the expression pattern of E-cadherin and EMT-related proteins of the sarcomatous component.

RESULTS

The expression score of E-cadherin decreased in the order of sarcomatous > transitional > carcinomatous components (P < 0.01). Although there were significant differences in the immunohistochemical scores of Slug, Twist, and Zeb1 between carcinomatous and transitional components (P < 0.01), the significant difference in immunohistochemical score of Zeb1 between transitional and sarcomatous components was found (P < 0.05). Furthermore, APCs were divided into 2 subgroups based on the expression patterns of E-cadherin and EMT-related proteins (hierarchical clustering analysis). Consequently, these subgroups were distinguished by Twist expression.

CONCLUSIONS

Epithelial-mesenchymal transition plays an essential role in the pathogenesis of APC.

CCR7 preservation via histone deacetylase inhibition promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells

The effects of Histone deacetylase (HDAC) inhibition on epithelial-mesenchymal transition (EMT) differs in various types of cancers. However, its function in hepatocellular carcinoma (HCC) is not well-explored. In this study, we investigated the effect of HDAC inhibition on EMT in HCC cells by using trichostatin A (TSA) and valproic acid (VPA). The results showed that TSA/VPA significantly induced EMT phenotype, as demonstrated by the decreased level of E-cadherin, increased level of N-cadherin, vimentin, Twist and snail, and enhanced capacity of cell migration and invasion. In addition, CCR7 was speculated and confirmed as a function target of HDAC inhibition. CCR7 promotes the progression of HCC and is associated with poor survival. Knockdown of CCR7 significantly attenuated the effect of TSA on EMT. Moreover, our results demonstrated that HDAC inhibition up-regulates CCR7 via reversing the promoter hypoacetylation and increasing CCR7 transcription. Taken together, our study has identified the function of HDAC in EMT of HCC and suggested a novel mechanism through which TSA/VPA exerts its carcinogenic roles in HCC. HDAC inhibitors require careful caution before their application as new anticancer drugs.

CCR7 regulates ANO6 to promote migration of pancreatic ductal adenocarcinoma cells via the ERK signaling pathway

The increase in migratory ability of pancreatic ductal adenocarcinoma cells is a key event in the development of metastasis to the lymph nodes and distant organs. Although the C-C motif chemokine receptor 7 (CCR7) and its ligand, C-C motif chemokine ligand 21 (CCL21), have been revealed to serve an important role in tumor migration, their precise roles and potential underlying mechanisms remain largely unknown. The present study revealed that overexpression of CCR7 significantly promoted BxPC-3 cell migration, accompanied by the induction of anoctamin 6 (ANO6) expression, indicating that ANO6 is a downstream target of CCR7 signaling. Furthermore, the level of phosphorylated extracellular signal-regulated kinase (ERK) was significantly increased in CCR7-overexpressing BxPC-3 cells, indicating that ERK may be a potential mediator of CCR7-regulated ANO6 expression in BxPC-3 cells. To characterize the receptor-mediated pathway, a specific ERK inhibitor, U0126, was used, which reduced BxPC-3 cell migration and the expression of ANO6. In summary, the results of the present study demonstrate that CCR7 promoted BxPC-3 cell migration by regulating ANO6 expression perhaps via activation of the ERK signaling pathway.

Functions of chemokines in the perineural invasion of tumors (Review)

The perineural invasion (PNI) of malignant tumors is a form of tumor progression in which cancer cells encroach along nerves. PNI hinders curative resection. Residual tumor cells in or around nerves can bring about local recurrence, infiltration and metastasis. This behavior is usually associated with a poor clinical prognosis. Therefore, it is necessary to investigate novel ligand-receptor crosstalk between nerves and tumor cells that promote the process of PNI. Chemokines are regarded as one of pivotal factors involved in the process of PNI. The present review collates information provided by previous studies with regard to the role of chemokines in PNI. The study presents a definition of PNI in cancer, generalizes the biological characteristics and the expression of chemokines and their receptors in cancer types associated with PNI, and discusses the underlying molecular mechanisms of chemokines, the reciprocal interactions between chemokines and other factors in PNI, and the interconnectivity of the microenvironment and chemokines. The aim of the review is to thoroughly illustrate the molecular cues of chemokines in cancer with PNI and to identify novel antitumor targets.

The crosstalk between p38 and Akt signaling pathways orchestrates EMT by regulating SATB2 expression in NSCLC cells

Epithelial–mesenchymal transition is a crucial event for metastasis and could be mediated by several pathways such as phosphoinositide 3-kinase/Akt, mitogen-activated protein kinases, as well as many epigenetic regulators. Special AT-rich sequence-binding protein 2 is an epigenetic regulator involved in epithelial–mesenchymal transition and osteoblastic differentiation. It has been reported that the crosstalk between several pathways is responsible for the regulation of epithelial–mesenchymal transition in cancer cells. However, crosstalks between p38 and Akt pathways involved in epithelial–mesenchymal transition are still unknown. We recently reported that there is a crosstalk between p38 and Akt pathways in non-small-cell lung carcinoma cells, and this crosstalk is associated with E-cadherin and special AT-rich sequence-binding protein 2 expressions. Therefore, we aimed to determine whether this crosstalk has a mediator role in the regulation of epithelial–mesenchymal transition in non-small-cell lung carcinoma. Our results showed that inhibition of p38 leads to the disruption of this crosstalk via decreased expression of phosphatase and tensin homolog (PTEN) and subsequently increased activation of Akt in non-small-cell lung carcinoma cells. Then, we found that p38 inhibition upregulated special AT-rich sequence-binding protein 2 expression and reversed epithelial–mesenchymal transition in non-small-cell lung carcinoma cells. Furthermore, special AT-rich sequence-binding protein 2 knockdown abolished the effect of p38 inhibition on epithelial–mesenchymal transition in non-small-cell lung carcinoma cells. In conclusion, our results strongly indicate that the crosstalk between p38 and Akt pathways can determine special AT-rich sequence-binding protein 2 expression and epithelial character of non-small-cell lung carcinoma cells, and special AT-rich sequence-binding protein 2 is a critical epigenetic regulator for epithelial–mesenchymal transition mediated by p38 pathway in non-small-cell lung carcinoma. Our findings will contribute to illuminate the molecular mechanisms of the epithelial–mesenchymal transition process that has a critical significance for lung cancer metastasis.

The Critical Role of SRPK1 in EMT of Human Glioblastoma in the Spinal Cord

Up to now, the serine-arginine protein kinase 1 (SRPK1) has been suggested as an important signal mediator, which is implicated in the development of cancers. Unfortunately, some molecular pathways in SRPK1-mediated epithelial-mesenchymal transition (EMT) in human spinal glioblastoma have been not elucidated. In this work, we detected the expression of SRPK1 in human spinal glioblastoma tissues and GBM cell lines and analyzed the relevant molecular proteins using in vitro experiments, including RT-PCR, gene silencing, and Western blot. In this study, RT-PCR and Western blot revealed that the expression of SRPK1 mRNA and protein became higher in all six spinal glioblastoma specimens; however, its expression was low in matched normal specimens. We also demonstrated SRPK1 expression facilitated the proliferation of U87 and U251 cells and inhibited the apoptosis in U87 and U251 cells. Also, SRPK1 promoted the expression of EMT-regulating markers, involving N-cadherin, Snail, and MMP9 and decreased the expression of mesenchymal marker E-cadherin. Moreover, knockdown of SRPK1 significantly inhibited the expression levels of p-Akt rather than t-Akt. In conclusion, knockdown of SRPK1 inhibited glioblastoma cell proliferation, invasion, and EMT process via suppressing p-Akt signaling pathway. This study also lays a new foundation for the clinically biological treatment.

MiR-195 inhibits the proliferation of human cervical cancer cells by directly targeting cyclin D1

MicroRNAs are important regulators of multiple cellular processes, and aberrant miRNA expression has been observed in human cervical cancer (CC). The present study was to evaluate the level of miR-195 and cyclin D1 in CC tissues and cells. We further investigated the molecular mechanisms of miR-195 and cyclin D1 in CC cell lines HeLa and SiHa. Here, we found that miR-195 expression was down-regulated in CC tissues, and HeLa and SiHa cells (all p < 0.001). By contrast, cyclin D1 was up-regulated. Furthermore, the expression of miR-195 was inversely proportional to that of cyclin D1 mRNA or protein (p = 0.013, p = 0.015, respectively). In vitro studies demonstrated that the overexpression of miR-195 played a suppressor role in the proliferation of HeLa and SiHa cells and promoted cell apoptosis. Luciferase reporter assays confirmed that miR-195 binding to the 3'-UTR regions of cyclin D1 inhibited the expression of cyclin D1 in HeLa and SiHa cells. However, the inhibitor of miR-195 promoted the expression of cyclin D1 and cell proliferation. In conclusion, our data suggest that miR-195 may have the potential role in treatment of CC patients, as well as miR-195 is a novel regulator of invasiveness and tumorigenicity in CC cells by targeting cyclin D1. MiR-195/cyclin D1 pathway may be a useful therapeutic agent in CC patients.