CC chemokine ligand 18 and IGF-binding protein 6 as potential serum biomarkers for prostate cancer

The Potential of Extracellular Matrix- and Integrin Adhesion Complex-Related Molecules for Prostate Cancer Biomarker Discovery

Prostate cancer is among the top five cancer types according to incidence and mortality. One of the main obstacles in prostate cancer management is the inability to foresee its course, which ranges from slow growth throughout years that requires minimum or no intervention to highly aggressive disease that spreads quickly and resists treatment. Therefore, it is not surprising that numerous studies have attempted to find biomarkers of prostate cancer occurrence, risk stratification, therapy response, and patient outcome. However, only a few prostate cancer biomarkers are used in clinics, which shows how difficult it is to find a novel biomarker. Cell adhesion to the extracellular matrix (ECM) through integrins is among the essential processes that govern its fate. Upon activation and ligation, integrins form multi-protein intracellular structures called integrin adhesion complexes (IACs). In this review article, the focus is put on the biomarker potential of the ECM- and IAC-related molecules stemming from both body fluids and prostate cancer tissue. The processes that they are involved in, such as tumor stiffening, bone turnover, and communication via exosomes, and their biomarker potential are also reviewed.

CCL18 Knockdown Suppresses Cell Growth and Migration in Thyroid Cancer

BACKGROUND

Chemokine (C-C motif) ligand 18 (CCL18) is a chemokine that plays a key role in immune and inflammatory responses. In recent years, CCL18 participates in the development and progression of various cancers, but its expression and role in thyroid cancer (TC) remain unclear.

METHODS

RT-qPCR assay and Western blot assay were used to explore the expression level of CCL18 in TC tissues and cells. Cell proliferation was measured by MTT assay. Transwell assay was adopted to detect cell migration in TC cells. Dual luciferase reporter assay was performed to assess the relationship between CCL18 and miR-149-5p.

RESULTS

There was an uptrend of CCL18 in TC tissues and cells. Our findings indicated that CCL18 overexpression facilitated lymph node metastasis in patients with TC. CCL18 silencing was found to inhibit cell migration, proliferation, and EMT progression in TC cells. CCL18 was proved to be a target gene of miR-149-5p. Additionally, miR-149-5p weakened the effect of CCL18 in the progression of TC.

CONCLUSION

Therefore, our results indicated that CCL18 knockdown restrained TC progression and suggested that CCL18 might be a potential therapeutic target for TC.

The immunosuppressive and pro-tumor functions of CCL18 at the tumor microenvironment

Chemokines are essential mediators of immune cell trafficking. In a tumor microenvironment context, chemotactic cytokines are known to regulate the migration, positioning and interaction of different cell subsets with both anti- and pro-tumor functions. Additionally, chemokines have critical roles regarding non-immune cells, highlighting their importance in tumor growth and progression. CCL18 is a primate-specific chemokine produced by macrophages and dendritic cells. This chemokine presents both constitutive and inducible expression. It is mainly associated with a tolerogenic response and involved in maintaining homeostasis of the immune system under physiological conditions. Recently, CCL18 has been noticed as an important component of the complex chemokine system involved in the biology of tumors. This chemokine induces T regulatory cell differentiation and recruitment to the tumor milieu, with subsequent induction of a pro-tumor (M2-like) macrophage phenotype. CCL18 is also directly involved in cancer cell-invasion, migration, epithelial-to-mesenchymal transition and angiogenesis stimulation, pinpointing an important role in the promotion of cancer progression. Interestingly, this chemokine is highly expressed in tumor tissues, particularly at the invasive front of more advanced stages (e.g. colorectal cancer), and high levels are detected in the serum of patients, correlating with poor prognosis. Despite the promising role of CCL18 as a biomarker and/or therapeutic target to hamper disease progression, its pleiotropic functions in a context of cancer are still poorly explored. The scarce knowledge concerning the receptors for this chemokine, together with the insufficient insight on the downstream signaling pathways, have impaired the selection of this molecule as an immediate target for translational research. In this Review, we will discuss recent findings concerning the role of CCL18 in cancer, integrate recently disclosed molecular mechanisms and compile data from current clinical studies.

CCL18 in the Progression of Cancer

A neoplastic tumor consists of cancer cells that interact with each other and non-cancerous cells that support the development of the cancer. One such cell are tumor-associated macrophages (TAMs). These cells secrete many chemokines into the tumor microenvironment, including especially a large amount of CCL18. This chemokine is a marker of the M2 macrophage subset; this is the reason why an increase in the production of CCL18 is associated with the immunosuppressive nature of the tumor microenvironment and an important element of cancer immune evasion. Consequently, elevated levels of CCL18 in the serum and the tumor are connected with a worse prognosis for the patient. This paper shows the importance of CCL18 in neoplastic processes. It includes a description of the signal transduction from PITPNM3 in CCL18-dependent migration, invasion, and epithelial-to-mesenchymal transition (EMT) cancer cells. The importance of CCL18 in angiogenesis has also been described. The paper also describes the effect of CCL18 on the recruitment to the cancer niche and the functioning of cells such as TAMs, regulatory T cells (T_reg), cancer-associated fibroblasts (CAFs) and tumor-associated dendritic cells (TADCs). The last part of the paper describes the possibility of using CCL18 as a therapeutic target during anti-cancer therapy.

MiR-484 suppressed proliferation, migration, invasion and induced apoptosis of gastric cancer via targeting CCL-18

Gastric cancer is a common and high-incidence malignant gastro-intestinal cancer that seriously threatens human life. Evidence suggests that microRNAs (miRNAs) play an essential role in regulating the occurrence and development of gastric cancer, but the possible mechanisms and effects remain to be further explored. In the present study, a new tumour suppresser function of miR-484 was identified in gastric cancer. The expression of miR-484 was obviously decreased, and the expression of CCL-18 was obviously increased in gastric cancer tissues and cell lines. In addition, upregulation of miR-484 suppressed cell proliferation, migration and invasion, and induced cell cycle arrest in G1 phase and cell apoptosis in gastric cancer cells. Besides, miR-484 mimics could block the PI3K/AKT signalling pathway. Moreover, CCL-18 was confirmed as a direct target of miR-484 by binding its 3'-UTR, and over-expression of CCL-18 could restore the effects of miR-484 on the growth and metastasis of gastric cancer. Finally, in vivo experiments showed that over-expression of miR-484 inhibited the subcutaneous tumorigenicity of gastric cancer cells, and the inhibition was blocked after over-expression of CCL-18. To conclude, miR-484 expression was downregulated in gastric cancer tissues and cells and played an anti-cancer role in the occurrence and development of gastric cancer, which may be achieved by inhibiting the expression of transcription factor CCL-18 and blocking the PI3K/AKT pathway.

ARNT-dependent CCR8 reprogrammed LDH isoform expression correlates with poor clinical outcomes of prostate cancer

Lactate dehydrogenase isozyme (LDH) is a tetramer constituted of two isoforms, LDHA and LDHB, the expression of which is associated with cell metabolism and cancer progression. Our previous study reveals that CC-chemokine ligand-18 (CCL18) is involved in progression of prostate cancer (PCa).This study aims to investigate how CCL18 regulates LDH isoform expression, and therefore, contributes to PCa progression. The data revealed that the expression of LDHA was upregulated and LDHB was downregulated in PCa cells by CCL18 at both messenger RNA and protein levels. The depletion of CCR8 reduced the ability of CCL18 to promote the proliferation, migration, and lactate production of PCa cells. Depletion of a CCR8 regulated transcription factor, ARNT, significantly reduced the expression of LDHA. In addition, The Cancer Genome Atlas dataset analyses revealed a positive correlation between CCR8 and ARNT expression. Two dimension difference gel electrophoresis revealed that the LDHA/LDHB ratio was increased in the prostatic fluid of patients with PCa and PCa tissues. Furthermore, increased LDHA/LDHB ratio was associated with poor clinical outcomes of patients with PCa. Together, our results indicate that the CCR8 pathway programs LDH isoform expression in an ARNT dependent manner and that the ratio of LDHA/LDHB has the potential to serve as biomarkers for PCa diagnosis and prognosis.

Macrophage-derived CCL18 promotes osteosarcoma proliferation and migration by upregulating the expression of UCA1

Osteosarcoma (OS), which is the most common primary malignant bone tumor, has a high incidence of pulmonary metastasis. CCL18 (C-C motif chemokine ligand 18), which is secreted by tumor-associated macrophages (TAMs), has been found to be increased in various tumors and is associated with tumor metastasis. However, the role of CCL18 in OS remains unclear. Here, we evaluated the effect of CCL18 on the OS cell lines MG63 and 143B and explored its potential mechanisms. We found that CCL18 enhanced the proliferation and migration of OS cells and upregulated UCA1 through transcription factor EP300. Subsequently, we further revealed that the downstream Wnt/β-catenin signaling pathway participated in this process. In addition, the high expression of CCL18 in both tissue and serum from patients was closely related to pulmonary metastasis and poor survival in OS patients. The tumor xenograft models also showed that CCL18 promoted the metastasis of OS cells. Collectively, our study indicated that macrophage-derived CCL18 promotes OS proliferation and metastasis via the EP300/UCA1/Wnt/β-catenin pathway and that CCL18 may be used as a prognostic marker and therapeutic target of OS. KEY MESSAGES: CCL18 promotes proliferation and migration of osteosarcoma cells by EP300/ UCA1/ Wnt/β-catenin pathway. CCL18⁺ TAMs are significantly correlated with pulmonary metastasis and poor survival in osteosarcoma patients. CCL18 may be used as a prognostic marker and therapeutic target for osteosarcoma.

IGFBP6 is a novel nasopharyngeal carcinoma prognostic biomarker

Insulin-like growth factor binding proteins (IGFBPs) play critical roles in carcinogenesis. This study assessed the impact of IGFBP6 on the progression of nasopharyngeal carcinoma (NPC). Using immunohistochemical analysis, we found that IGFBP6 was differentially expressed in primary malignant NPC tissues. Clinical samples were divided into two groups: IGFBP6(+) and IGFBP6(−). Five years of follow-up revealed that overall survival and distant metastasis-free survival rates were significantly higher in the IGFBP6(+) than IGFBP6(−) group. We also used real-time PCR, ELISA and western blot assays to measure IGFBP6 levels in five NPC cell lines (CNE1, CNE2, HONE1, HK1 and SUNE1). All the cell lines expressed IGFBP6, but at different levels, reflecting disease heterogeneity. In addition, exogenous expression of IGFBP6 inhibited CNE2 cell proliferation and invasion in vitro. IGFBP6 knockdown activated the GSK3β/β-catenin/cyclin D1 pathway and enhanced CNE2 tumor cell growth and metastasis in a mouse model. These results suggest that IGFBP6 may be an independent prognostic biomarker for NPC.

Plasma Peptidome as a Source of Biomarkers for Diagnosis of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the bile duct cancer which constitutes one of the important public health problems in Thailand with high mortality rate, especially in the Opisthorchis viverrini (a parasite risk factor for CCA) endemic area of the northeastern region of the country. This study aimed to identify potential biomarkers from the plasma peptidome by CCA patients. Peptides were isolated using 10 kDa cut-off filter column and the flow-through was then used as a peptidome for LC-MS/MS analysis. A total of 209 peptides were obtained. Among these, 15 peptides were concerned with signaling pathways and 12 related to metabolic, regulatory, and biosynthesis of secondary metabolite pathways. Five exclusive peptides were identified as potential biomarkers, i.e. ETS domain-containing transcription factor ERF (P50548), KIAA0220 (Q92617), phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit beta isoform isoform 1 (P42338), LP2209 (Q6XYC0), and casein kinase II subunit alpha (P19784). Three of these biomarkers are signaling related molecules. A combination of these biomarkers for CCA diagnosis is proposed.

The Expression of IGFBP6 after Spinal Cord Injury: Implications for Neuronal Apoptosis

IGFBP6, a member of the insulin-like growth factor-binding proteins family that contains six high affinity IGFBPs, modulates insulin-like growth factor (IGF) activity and also showed an independent effect of IGF, such as growth inhibition and apoptosis. However, the role of IGFBP6 in spinal cord injury (SCI) remains largely elusive. In this study, we have performed an acute SCI model in adult rats and investigated the dynamic changes of IGFBP6 expression in the spinal cord. Our results showed that IGFBP6 was upregulated significantly after SCI, which was paralleled with the levels of apoptotic proteins p53 and active caspase-3. Immunofluorescent labeling showed that IGFBP6 was co-localizated with active caspase-3 and p53 in neurons. To further investigate the function of IGFBP6, an apoptosis model was established in primary neuronal cells. When IGFBP6 was knocked down by specific short interfering RNA (siRNA), the protein levels of active caspase-3 and Bax as well as the number of apoptotic primary neurons were significantly decreased in our study. Taken together, our findings suggest that the change of IGFBP6 protein expression plays a key role in neuronal apoptosis after SCI.

Insulin-like growth factor binding proteins 4-6

Insulin-like growth factor binding proteins (IGFBPs) 4-6 have important roles as modulators of IGF actions. IGFBP-4 and IGFBP-6 predominantly inhibit IGF actions, whereas IGFBP-5 may enhance these actions under some circumstances. IGFBP-6 is unique among the IGFBPs for its marked IGF-II binding preference. IGFBPs 4-6 are found in the circulation as binary complexes with IGFs that can enter tissues. Additionally, about half of the circulating IGFBP-5 is found in ternary complexes with IGFs and an acid labile subunit; this high molecular complex cannot leave the circulation and acts as an IGF reservoir. IGFBPs 4-6 also have IGF-independent actions. These IGFBPs are regulated in a cell-specific manner and their dysregulation may play a role in a range of diseases including cancer. However, there is no clear clinical indication for measuring serum levels of these IGFBPs at present.

CCL18 promotes the invasion and migration of gastric cancer cells via ERK1/2/NF-κB signaling pathway

CCL18 is a member of CCL chemokines and is frequently overexpressed in cancer. Elevated CCL18 expression has been reported to be associated with poor prognosis of gastric cancer. However, the molecular mechanisms of CCL18 in gastric cancer cells remain elusive. In our study, we found that CCL18 was highly expressed in different gastric cancer cells. CCL18 stimulation dose-dependently enhanced the invasion and migration of MGC-803 cells. Knockdown of endogenous CCL18 inhibited the invasion and migration of MGC-803 cells, whereas overexpression of CCL18 promoted the invasion and migration of MKN28 cells. We further found that CCL18 increased the expressions of MMP-3 and Slug and decreased the expression of E-cadherin in MGC-803 cells. In addition, CCL18 time-dependently induced activation of ERK1/2, IκBα, and NF-κB. These effects of CCL18 were prevented by ERK1/2 selective inhibitor U0126 as well as NF-κB selective inhibitor BAY117082. Taken together, our findings establish a signaling role for CCL18 in gastric cancer cells and identify that the CCL18/ERK1/2/NF-κB signaling pathway is essential for tumor invasiveness in gastric cancer cells. Thus, our data may provide knowledge for using CCL18 as a novel target for effective diagnosis and treatment of gastric cancer.

The insulin-like growth factor (IGF) axis as an anticancer target in prostate cancer

Prostate cancer (PCa) is the most common cancer and the second leading cause of cancer death in males. In recent years, several new targeting agents have been introduced for the treatment of advanced stages of the disease. However, development of resistance limits the efficacy of new drugs and there is a further need to develop additional novel treatment approaches. One of the most investigated targets in cancer research is the insulin-like growth factor (IGF) axis, whose receptors are overexpressed in several cancer entities including PCa. In preclinical studies in PCa, targeting of the IGF axis receptors showed promising anti-tumor effects. Currently available data on clinical studies do not meet the expectations for this new treatment approach. In this review we provide a summary of preclinical and clinical studies on the IGF axis in PCa including treatment with monoclonal antibodies and tyrosine kinase inhibitors. Moreover, we summarize preliminary results from ongoing studies and discuss limitations and side effects of the substances used. We also address the role of the IGF axis in the biomarkers setting including IGF-binding proteins and genetic variants.

Recent insights into the actions of IGFBP-6

IGFBP-6 is an O-linked glycoprotein that preferentially binds IGF-II over IGF-I. It is a relatively selective inhibitor of IGF-II actions including proliferation, survival and differentiation of a wide range of cells. IGFBP-6 has recently been shown to have a number of IGF-independent actions, including promotion of apoptosis in some cells and inhibition of angiogenesis. IGFBP-6 also induces migration of tumour cells including rhabdomyosarcomas by an IGF-independent mechanism. This chemotactic effect is mediated by MAP kinases. IGFBP-6 binds to prohibitin-2 on the cell surface and the latter is required for IGFBP-6-induced migration by a mechanism that is independent of MAP kinases. IGFBP-6 may enter the nucleus and modulate cell survival and differentiation. IGFBP-6 expression is decreased in a number of cancer cells and it has been postulated to act as a tumour suppressor. IGFBP-6 expression is increased in a smaller number of cancers, which may reflect a compensatory mechanism to control IGF-II actions or IGF-independent actions. The relative balance of IGF-dependent and IGF-independent actions of IGFBP-6 in vivo together with the related question regarding the roles of IGFBP-6 binding to IGF and non-IGF ligands are keys to understanding the physiological role of this protein.

Inflammation and prostate cancer: friends or foe?

INTRODUCTION

Prostate cancer is the most common non-cutaneous malignancy diagnosed in men. Moving from histological observations since a long time, it has been recognized that innate and adaptive immunity actively participates in the pathogenesis, surveillance, and progression of prostate cancer.

MATERIALS AND METHODS

A PubMed and Web of Science databases search was performed for studies providing evidence on the roles of the innate and adaptive immunity during the development and progression of prostate cancer.

CONCLUSIONS

There are growing evidences that chronic inflammation is involved in the regulation of cellular events in prostate carcinogenesis, including disruption of the immune response and regulation of the tumor microenvironment. This review discusses the role played by the innate and adaptive immune system in the local progression of prostate cancer, and the prognostic information that we can currently understand and exploit.