Stromal cell derived factor-1 and CXCR4 expression in colorectal cancer promote liver metastasis

Cx4Mab-1: A Novel Anti-Mouse CXCR4 Monoclonal Antibody for Flow Cytometry

The CXC chemokine receptor 4 (CXCR4, CD184) is a member of the G protein-coupled receptor family that is expressed in most leukocytes. Overexpression of CXCR4 is associated with poor prognosis in not only hematopoietic malignancy but also solid tumors. Because CXCR4 is an attractive target for tumor therapy, reliable preclinical murine models using anti-CXCR4 monoclonal antibodies (mAbs) have been warranted. This study established a novel anti-mouse CXCR4 (mCXCR4) mAb using the Cell-Based Immunization and Screening method. Flow cytometric analysis showed that an anti-mCXCR4 mAb, Cx4Mab-1 (rat IgG2a, kappa), recognized mCXCR4-overexpressed Chinese hamster ovary-K1 (CHO/mCXCR4) cells and endogenously mCXCR4-expressing mouse myeloma P3X63Ag8U.1 (P3U1) cells. Furthermore, Cx4Mab-1 did not recognize mCXCR4-knockout P3U1 cells. The dissociation constants of Cx4Mab-1 for CHO/mCXCR4 and P3U1 were determined as 6.4 × 10-9 M and 2.3 × 10-9 M, respectively, indicating that Cx4Mab-1 possesses a high affinity to both endogenous and exogenous mCXCR4-expressing cells. These results indicate that Cx4Mab-1 could be a useful tool for preclinical mouse models.

The pathological role of C-X-C chemokine receptor type 4 (CXCR4) in colorectal cancer (CRC) progression; special focus on molecular mechanisms and possible therapeutics

Colorectal cancer (CRC) is comprised of transformed cells and non-malignant cells including cancer-associated fibroblasts (CAF), endothelial vasculature cells, and tumor-infiltrating cells. These nonmalignant cells, as well as soluble factors (e.g., cytokines), and the extracellular matrix (ECM), form the tumor microenvironment (TME). In general, the cancer cells and their surrounding TME can crosstalk by direct cell-to-cell contact and via soluble factors, such as cytokines (e.g., chemokines). TME not only promotes cancer progression through growth-promoting cytokines but also provides resistance to chemotherapy. Understanding the mechanisms of tumor growth and progression and the roles of chemokines in CRC will likely suggest new therapeutic targets. In this line, a plethora of reports has evidenced the critical role of chemokine receptor type 4 (CXCR4)/C-X-C motif chemokine ligand 12 (CXCL12 or SDF-1) axis in CRC pathogenesis. In the current review, we take a glimpse into the role of the CXCR4/CXCL12 axis in CRC growth, metastasis, angiogenesis, drug resistance, and immune escape. Also, a summary of recent reports concerning targeting CXCR4/CXCL12 axis for CRC management and therapy has been delivered.

Which patients are prone to suffer liver metastasis? A review of risk factors of metachronous liver metastasis of colorectal cancer

Background

In recent years, with the increasing incidence of colorectal cancer (CRC) and its high fatality rate, CRC has seized the attention of the world. And liver metastasis, as the main cause of death of CRC, has become the leading cause of treatment failure in CRC, especially metachronous liver metastasis, have caused patients who underwent bowel resection to experience multiple tortures.

Main body

Metachronous liver metastasis has severely affected the quality of life and prognosis of patients. Therefore, in this review, we discuss risk factors for metachronous liver metastasis of CRC, which is the premise for effective intervention for CRC patients who suffer metachronous liver metastasis after undergoing surgery, as well as the signaling pathways associated with CRC.

Conclusion

The occurrence of metachronous liver metastasis is closely related to histology-based prognostic biomarkers, serum-based biomarkers, tumor microenvironment, pre-metastatic niche, liquid biopsy and tissue-based biomarkers. Further research is required to explore the risk factors associated with liver metastasis of CRC.

Interaction Between microRNAs and Myeloid-Derived Suppressor Cells in Tumor Microenvironment

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells generated during a series of pathologic conditions including cancer. MicroRNA (miRNA) has been considered as a regulator in different tumor microenvironments. Recent studies have begun to unravel the crosstalk between miRNAs and MDSCs. The knowledge of the effect of both miRNAs and MDSCs in tumor may improve our understanding of the tumor immune escape and metastasis. The miRNAs target cellular signal pathways to promote or inhibit the function of MDSCs. On the other hand, MDSCs transfer bioinformation through exosomes containing miRNAs. In this review, we summarized and discussed the bidirectional regulation between miRNAs and MDSCs in the tumor microenvironment.

Colorectal Cancer: The Contribution of CXCL12 and Its Receptors CXCR4 and CXCR7

Simple Summary

Many signaling pathways are involved in cancer progression, and among these pathways, the CXCL12 axis and its two receptors CXCR4 and CXCR7 are well described for many cancers. This review presents the current knowledge on the role played by each of the actors of this axis in colorectal cancer and on its consideration in the development of new therapeutic strategies.

Abstract

Colorectal cancer is one of the most common cancers, and diagnosis at late metastatic stages is the main cause of death related to this cancer. This progression to metastasis is complex and involves different molecules such as the chemokine CXCL12 and its two receptors CXCR4 and CXCR7. The high expression of receptors in CRC is often associated with a poor prognosis and aggressiveness of the tumor. The interaction of CXCL12 and its receptors activates signaling pathways that induce chemotaxis, proliferation, migration, and cell invasion. To this end, receptor inhibitors were developed, and their use in preclinical and clinical studies is ongoing. This review provides an overview of studies involving CXCR4 and CXCR7 in CRC with an update on their targeting in anti-cancer therapies.

Serum Levels of Stromal Cell-Derived Factor-1α and Vascular Endothelial Growth Factor Predict Clinical Outcomes in Head and Neck Squamous Cell Carcinoma Patients Receiving TPF Induction Chemotherapy

Chemokines, such as stromal cell-derived factor-1α (SDF-1α) and vascular endothelial growth factor (VEGF), are associated with clinical outcomes in several cancer types. This study aimed to investigate the role of SDF-1α and VEGF in the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) who underwent TPF induction chemotherapy (docetaxel, cisplatin, and 5-fluorouracil). A total of 77 HNSCC patients were enrolled and circulating SDF-1α and VEGF values were examined at two time points for each patient, including pre-TPF treatment (treatment-naïve) and post-TPF treatment but before chemoradiotherapy. The median progression-free survival (PFS) and overall survival (OS) were 18.1 and 32.9 months, respectively. Decreased SDF-1α and VEGF levels after TPF treatment, post-TPF SDF-1α < 1500 pg/mL and VEGF value < 150 pg/mL were independent prognostic factors for better PFS and OS in univariate and multivariate analyses. A combination of SDF-1α and VEGF values may predict clinical outcomes significantly. Our study confirmed the role of SDF-1α and VEGF in the disease progression of HNSCC, and that decreased SDF-1α and VEGF after TPF treatment and lower post-TPF SDF-1α and VEGF values were associated with better prognosis in HNSCC patients who received induction chemotherapy with TPF followed by chemoradiotherapy.

Elevated CXCL12 in the plasma membrane of locally advanced rectal cancer after neoadjuvant chemoradiotherapy: a potential prognostic marker

Background: Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) has been shown to improve sphincter preservation and local pelvic control, but the efficacy of nCRT plateaus due to metastasis. CXC chemokine ligand 12 (CXCL12) has a critical impact on cancer development and metastasis.

Methods: By investigating public databases containing LARC patient data, CXCL12, CXCR4 and FAPα expression was analyzed via the Tumor Immune Estimation Resource (TIMER) and GSEA. Immunohistochemistry was applied to a total of 121 surgically resected specimens consisting of 61 LARCs after nCRT and 60 LARCs with no nCRT and 16 cases with endoscopic resection of high-grade colorectal adenoma.

Results: By investigating public databases containing LARC patient data, CXCL12 expression is correlated with poor prognosis, immune cell infiltration, epithelial- mesenchymal transition, and angiogenesis in LARC. Furthermore, radiation selectively induced CXCL12, CXCR4 and FAPα expression in tumor tissues. Immunohistochemistry results showed that the levels of CXCL12, CXCR4, and FAPα in LARC cells after nCRT were higher than in LARC cells untreated with nCRT (p < 0.001 for each). Elevated levels of CXCL12 in the plasma membrane of LARC cells after nCRT demonstrated an association with the period of freedom from recurrence (FFR) in univariate and multivariate survival analyses (p = 0.005 and p = 0.031, respectively).

Conclusions: The expression of CXCL12 may influence the survival and invasive properties of LARC cells during nCRT and promote cancer recurrence. We suggest that CXCL12 expression in the plasma membrane of radioresistant LARC cells may be a predictive factor of recurrence and a viable therapeutic strategy to control radioresistant LARC recurrence.

Prognostic and Predictive Role of CXC Chemokine Receptor 4 in Metastatic Colorectal Cancer Patients

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. About 30% of patients present with metastatic disease involving predominantly the liver and a similar percentage will develop distant metastases later after removal of the primary tumor. In metastatic CRC, chemotherapies and biological drugs have prolonged survival for up to 30 months. However, there is a great need for biomarkers predictive of response and prognosis to optimize treatments. CXC chemokine receptor 4 (CXCR4) is a chemokine receptor; it binds to CXCL12 and plays a central role in colon cancer cells' growth and dissemination.

MATERIALS AND METHODS

CXCR4 was evaluated in CRC primary tissues by immunohistochemistry. Formalin-fixed, paraffin-embedded 4-μm tissue sections were immunostained using a biotin-streptavidin-peroxidase method and categorized into 2 semiquantitative classes: (i) absence of staining, ≤50% positive cells (negative/low) and (ii) >50% positive cells (high). Associations between clinic-pathologic variables and CXCR4 expression were evaluated using the χ test. The Kaplan-Meier product-limit method was applied to graph overall survival (OS). OS was defined as the time elapsed from diagnosis to death from any cause. Univariate analysis was carried out using the log-rank test. Cox proportional hazards regression was used to analyze the effect of several risk factors on OS.

RESULTS

Seventy-eight primary adenocarcinomas were analyzed; 26 were categorized as negative/low and 52 as high. Age, sex, performance status, site of metastases, KRAS mutational status, type of first-line therapy, and a number of therapy lines did not correlate with CXCR4 expression. Although not significant (P=0.0533), high CXCR4 expression was more frequently localized on the right side of the colon. Significant correlations were detected with grading (P=0.0041) and response to first-line anti-epidermal growth factor receptors agents (P<0.0001), bevacizumab (P=0.0029), and chemotherapy alone (P=0.0260). At a median follow-up of 53 months, 77 deaths have been registered. Grading [hazard ratio (HR): 1.42; confidence interval (CI): 0.89-2.28; P<0.0001], KRAS mutational status (HR: 1.73; CI: 1.03-290; P=0.0133), response to first-line chemotherapy (HR: 3.39; CI: 2.10-5.48; P<0.0001), and CXCR4 expression (HR: 3.18; CI: 2.01-5.02; P<0.0001) showed prognostic power at univariate and multivariate analyses.

CONCLUSION

In the present report, we show that CXCR4 expression on the primary tumor is an independent prognostic factor and correlates with response to first-line chemotherapy in metastatic CRC patients.

Targeting the Tumor Microenvironment in Brain Metastasis

Dynamic interplay between cancer cells and the surrounding microenvironment is a feature of the metastatic process. Successful metastatic brain colonization requires complex mechanisms that ultimately allow tumor cells to adapt to the unique microenvironment of the central nervous system, evade immune destruction, survive, and grow. Accumulating evidence suggests that components of the brain tumor microenvironment (TME) play a vital role in the metastatic cascade. In this review, the authors summarize the contribution of the TME to the development and progression of brain metastasis. They also highlight opportunities for TME-directed targeted therapy.

Nodal-induced L1CAM/CXCR4 subpopulation sustains tumor growth and metastasis in colorectal cancer derived organoids

Background: Colorectal cancer (CRC) is currently the third leading cause for cancer-related mortality. Cancer stem cells have been implicated in colorectal tumor growth, but their specific role in tumor biology, including metastasis, is still uncertain. Methods: Increased expression of L1CAM, CXCR4 and NODAL was identified in tumor section of patients with CRC and in patients-derived-organoids (PDOs). The expression of L1CAM, CXCR4 and NODAL was evaluated using quantitative real-time PCR, western blotting, immunofluorescence, immunohistochemistry and flow cytometry. The effects of the L1CAM, CXCR4 and NODAL on tumor growth, proliferation, migration, invasion, colony-formation ability, metastasis and chemoresistance were investigated both in vitro and in vivo. Results: We found that human colorectal cancer tissue contains cancer stem cells defined by L1CAM^high/CXCR4^high expression that is activated by Nodal in hypoxic microenvironment. This L1CAM^high/CXCR4^high population is tumorigenic, highly resistant to standard chemotherapy, and determines the metastatic phenotype of the individual tumor. Depletion of the L1CAM^high/CXCR4^high population drastically reduces the tumorigenic potential and the metastatic phenotype of colorectal tumors. Conclusion: In conclusion, we demonstrated that a subpopulation of migrating L1CAM^high/CXCR4^high is essential for tumor progression. Together, these findings suggest that strategies aimed at modulating the Nodal signaling could have important clinical applications to inhibit colorectal cancer-derived metastasis.

Prognostic significance of CD8+ T-cells density in stage III colorectal cancer depends on SDF-1 expression

Since colorectal cancer (CRC) remains one of the most common malignancies, a tremendous amount of studies keep taking place in this field. Over the past 25 years, a notable part of the scientific community has focused on the association between the immune system and colorectal cancer. A variety of studies have shown that high densities of infiltrating CD8+ T-cells are associated with improved disease-free and overall survival in CRC. Stromal cell-derived factor-1 (SDF-1) is a protein that regulates leukocyte trafficking and is variably expressed in several healthy and malignant tissues. There is strong evidence that SDF-1 has a negative prognostic impact on a variety of solid tumors. However, the existing data do not provide sufficient evidence that the expression of SDF-1 has an influence on CRC. Knowing nowadays, that the microenvironment plays a crucial role in the development of cancer, we hypothesized that the expression of SDF-1 in CRC could influence the prognostic significance of CD8+ T-cells, as an indicator of the essential role of the immune microenvironment in cancer development. Therefore, we explored the combined prognostic significance of CD8+ T-cell density and SDF-1 expression in a large CRC collective. We analyzed a tissue microarray of 613 patient specimens of primary CRCs by immunohistochemistry (IHC) for the CD8 + T-cells density and the expression of SDF-1 by tumor cells and tumor-infiltrating immune cells. Besides, we analyzed the expression of SDF-1 at the RNA level in The Cancer Genome Atlas cohort. We found that the combined high CD8+ T-cell infiltration and expression of SDF-1 shows a favorable 5-year overall survival rate (66%; 95% CI 48-79%) compared to tumors showing a high expression of CD8+ T-cell only (55%; 95% CI 45-64%; p = 0.0004). After stratifying the patients in nodal negative and positive groups, we found that the prognostic significance of CD8+ T-cell density in nodal positive colorectal cancer depends on SDF-1 expression. Univariate and multivariate Hazard Cox regression survival analysis considering the combination of both markers revealed that the combined high expression of SDF-1 and CD8+ T-cell density was an independent, favorable, prognostic marker for overall survival (HR = 0.34, 95% CI 0.17-0.66; p = 0.002 and HR = 0.45, 95% CI 0.23-0.89; p = 0.021, respectively). In our cohort there was a very weak correlation between SDF-1 and CD8+ T-cells (rs = 0.13, p = 0.002) and in the trascriptomic expression of these two immune markers display a weak correlation (rs = 0.28, p < 0.001) which was significantly more pronounced in stage III cancers (rs = 0.40, p < 0.001). The combination of high CD8+ T-cell density and expression of SDF-1 represents an independent, favorable, prognostic condition in CRC, mostly in patients with stage III disease.

Prognostic Value of SDF-1α Expression in Patients with Esophageal Squamous Cell Carcinoma Receiving Esophagectomy

Stromal cell-derived factor-1α (SDF-1α) is a chemokine that has been reported to be involved in tumor progression in several malignancies. This study aimed to evaluate the crucial role of SDF-1α in patients with esophageal squamous cell carcinoma (ESCC) who underwent esophagectomy. A total of 169 patients with ESCC were identified, including overexpression of SDF-1α in 60 patients and low expression of SDF-1α in 109 patients by immunohistochemical analysis. Two ESCC cell lines, TE1 and KYSE30, were selected to evaluate the tumor cell proliferative effect of SDF-1α. Univariate and multivariate analyses showed that high tumor (T) status, positive lymph node metastasis, tumors located in the upper esophagus, and SDF-1α overexpression were significantly related to worse disease-free survival and overall survival. In addition, the two cell lines were treated with SDF-1α, AMD3100 (an SDF-1α-ligand receptor antagonist), and chemotherapeutic agents (cisplatin). Our in vitro study results showed that SDF-1α promoted the proliferation of tumor cells, and blocking the SDF-1α pathway displayed a growth inhibition effect in a dose-dependent manner. SDF-1α plays an important role in the progression of ESCC and is an independent prognostic factor for ESCC patients who underwent esophagectomy.

Exosome-encapsulated miRNAs contribute to CXCL12/CXCR4-induced liver metastasis of colorectal cancer by enhancing M2 polarization of macrophages

Tumor-associated macrophages (TAMs) are important immunocytes associated with cancer metastasis. However, whether TAMs play a dominant role in mediating CXCL12/CXCR4-induced liver metastasis of colorectal cancer (CRC) remains unexplored. Herein, we found that CD206⁺ TAMs, which infiltrated at the invasive front, were correlated with CXCR4 expression and liver metastasis of CRC in clinical specimens. Several miRNAs (miR-25-3p, miR-130b-3p, miR-425-5p), upregulated in CRC cells by activation of the CXCL12/CXCR4 axis, could be transferred to macrophages via exosomes. These exosomal miRNAs induced M2 polarization of macrophages by regulating PTEN through activation of PI3K/Akt signaling pathway. In turn, M2 polarized macrophages promoted cancer metastasis by enhancing epithelial-mesenchymal transition (EMT) and secreting vascular endothelial growth factor (VEGF). Co-culture of CRC cells with macrophages transfected with these miRNAs or treated with exosomes enhanced their metastatic capacity both in vitro and in vivo. Clinically, the serum levels of exosomal miR-25-3p, miR-130b-3p and miR-425-5p were correlated with progression and metastasis of CRC. In conclusion, these results reveal a crucial role of exosomal miRNAs in mediating the crosstalk between CXCR4 overexpressing cancer cells and TAMs, providing potential therapeutic targets for circumventing liver metastasis of CRC.

Effects of high-fat diet-induced adipokines and cytokines on colorectal cancer development

Colorectal cancer (CRC) is the third most common tumor worldwide, and recent epidemiological studies have indicated that obesity contributes to the morbidity and mortality of CRC. Furthermore, obesity‐related adipokines have been shown to be closely related to the incidence of CRC, but the underlying mechanisms are unclear. Here, we investigated the effects of high‐fat diet‐induced adipokines and cytokines on the development of CRC in vitro and in vivo. For the in vivo assays, we divided 2‐week‐old C57BL/6J‐ApcMin/J male mice into three groups: normal‐fat diet (ND), high‐fat and high‐sugar feed (HFHS), and high‐fat and low‐sugar feed (HFLS). After 1 week, all mice were injected with 20 mg·kg⁻¹ 1,2‐dimethylhydrazine once weekly for 10 consecutive weeks. Body weight, liver weight, epididymal fat weight and blood glucose levels were greatly increased in HFHS and HFLS groups compared with the ND group, and the expression levels of some adipokines and cytokines were obviously higher in HFHS or HFLS mice compared with ND mice. For the in vitro assays, HCT116 CRC cells were treated with sera of ND, HFHS or HFLS groups, or serum‐free media as a negative control. We observed that sera derived from HFHS or HFLS mice that contain excess adipokines and cytokines promoted the proliferation, migration and invasion of HCT116 cells compared with the ND sera‐conditioned medium or serum‐free medium group. Therefore, high‐fat diet‐induced adipokines and cytokines may promote the progression of CRC in vivo and in vitro.

We investigated the effects of high‐fat diet‐induced adipokines and cytokines in the development of colorectal cancer. Some adipokines and cytokines were obviously higher in obese mice than in normal mice. Obesity‐induced adipokines and cytokines promoted the proliferation, migration and invasion of HCT116 cells. Therefore, high‐fat diet‐induced adipokines and cytokines may accelerate the progression of colorectal cancer.

CXCR4 as a prognostic biomarker in gastrointestinal cancer: a meta-analysis

Background: CXCR4 is a member of the C-X-C chemokine receptor family, which is associated with multiple types of cancer. Although it has been widely reported, the prognostic value of CXCR4 expression in gastrointestinal (GI) cancer remains controversial. Methods: A meta-analysis was conducted to investigate the relationship between CXCR4 and prognosis of patients with GI cancer. Subgroup analysis was also performed according to tumour subtypes and heterogeneity test. Results: A total of 24 studies including 3637 cases suggested that overexpression of CXCR4 is significantly associated with overall survival (OS) for patients with GI cancer (HR = 1.71, 95% CI = 1.45-2.03, p = 0.000). Subgroup analysis also indicated that high CXCR4 expression in oesophagus, gastric and colorectal cancer all predicted a worse prognosis (HR = 1.52, 95% CI = 1.26-1.84, p = 0.001 for oesophagus cancer; HR = 1.59, 95% CI = 1.10-2.30, p = 0.015 for gastric cancer; HR = 2.21, 95% CI = 1.56-3.14, p = 0.000 for colorectal cancer). Conclusions: CXCR4 may serve as a prognostic indicator in GI cancer patients.

microRNA-193a-5p inhibits migration of human HT-29 colon cancer cells via suppression of metastasis pathway

PURPOSE

Altered expression of microRNAs (miRNAs) is indicated strongly in colorectal cancer (CRC). This study aims to evaluate the inhibitory role of miR-193a-5p on epithelial-mesenchymal transition markers in CRC lines. The cellular effects and potential mechanisms of miR-193a-5p were also examined.

METHODS

Quantitative reverse-transcription polymerase chain reaction (RT-PCR) was performed to determine the expression of miR-193a-5p in three CRC cell lines (HCT-116, SW-480, and HT-29) and its impact on metastasis-related genes ( vimentin and CXCR4) before and after mimic transfection. Of those, the cell line with the highest changes was selected for the next upcoming experiments such as wound-healing assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and annexin-V staining tests.

RESULTS

Our results revealed that miR-193a-5p was significantly downregulated in three CRC cell lines and that HT-29 displayed the most decrease ( P < 0.0001). The restoration of miR-193a-5p in human HT-29 cell line inhibited cell migration. But, miR-193a-5p transfection did not affect cell viability and had no significant effect on apoptosis induction. Also, the quantitative RT-PCR analysis of miR-193a-5p mimic transfected cells revealed a significant increase in miR-193a-5p messenger RNA (mRNA) expression level ( P < 0.0001) with reduction of vimentin and CXCR4 mRNA expression levels in HT-29 cell line ( P < 0.01 and < 0.05, respectively).

CONCLUSION

Our results indicated that miR-193a-5p acts as a tumor suppressor miRNA and its downregulation plays an important role in metastasis via upregulation of metastasis-related genes in CRC. Therefore, it can be considered as a potential therapeutic target for applying in CRC management in the future.

Clinical Evaluation of Preoperative Radiotherapy Combined with FOLFOX Chemotherapy on Patients with Locally Advanced Colon Cancer

This study explores the effect of preoperative radiotherapy combined with FOLFOX chemotherapy on patients with locally advanced colon cancer (LACC). Data of 102 patients with LACC were retrospectively analyzed. All received surgical resection plus postoperative FOLFOX chemotherapy; whereas 58 patients underwent preoperative radiotherapy combined with FOLFOX chemotherapy (CRT group, combined with radiotherapy treatment group), 44 patients did not undergo radiotherapy (non-CRT group). Short-and long-term effects as well as operative complications were compared. The optical density values of the caudal-related homeobox transcription factor 2 and inhibitor of growth 4 in lesions, and malignant molecules including vascular endothelial growth factor and cathepsin-D in serum were compared. The CRT group showed higher total pathological complete tumor response rate and resection rate, and lower incidence of incisional infection than the non-CRT group (all P < 0.05). The CRT group was significantly better in the three-year disease-free survival than the non-CRT group ( P < 0.05), but slightly better in the three-year overall survival and disease-free survival in the first, second, and third years ( P > 0.05). The optical density values of the caudal-related homeobox transcription factor 2 and inhibitor of growth 4 were higher than those in the non-CRT group (both P < 0.05). The levels of serum vascular endothelial growth factor and cathepsin-D in the CRT group were lower than those in the non-CRT group (both P < 0.05). Preoperative radiotherapy combined with FOLFOX chemotherapy can improve the resection rate and the pathological complete response rate in LACC surgery, and improve the survival time and the disease-free survival condition.

CXCL12/CXCR4 promotes inflammation-driven colorectal cancer progression through activation of RhoA signaling by sponging miR-133a-3p

Background

Activation of CXCL12/CXCR4 axis has been found to be associated with invasion and metastasis in many cancers. However, the underlying mechanism remains elusive. Increasing data highlight that non-coding RNAs are linked to CRC progression.

Methods

The effects of CXCR4 were investigated using villin-CXCR4 transgenic mice model by flow cytometry assay, immunohistochemistry, and Western blot. The mechanism was explored through bioinformatics, luciferase reporter assay and RNA immunoprecipitation assay.

Results

We found that high CXCR4 expression exacerbated colitis-associated cancer in villin-CXCR4 transgenic mice. CXCR4^+/−Apc^min/+ compound mutant mice demonstrated higher colorectal tumorigenesis than Apc^min/+ mice. Furthermore, overexpression of CXCR4 was found to promote the epithelial-mesenchymal transition (EMT) and infiltration of myeloid-derived suppressor cells (MDSCs) and macrophages in colonic tissue, accelerating colitis-associated and Apc mutation-driven colorectal tumorigenesis and progression. Notably, miR-133a-3p was found to be significantly decreased in HCT116 cells overexpressing CXCR4 by miRNA sequencing. miR-133a-3p was proved to target RhoA, which is involved in cytoskeletal reorganization that drive cell motility. Importantly, CXCL12/CXCR4-induced upregulation of lncRNA XIST functioned as a ceRNA to sponge miR-133a-3p, thereby liberating the repression of RhoA by miR-133a-3p. The negative correlation of miR-133a-3p with RhoA was also confirmed in human CRC tissues and CXCR4^+/− mice.

Conclusions

Our findings revealed the critical role of CXCR4 in promoting progression of inflammatory colorectal cancer through recruiting immunocytes and enhancing cytoskeletal remodeling by lncRNA XIST/ miR-133a-3p/ RhoA signaling. These results provide novel potential therapeutic targets for hindering CXCL12/CXCR4-induced CRC progression.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-1014-x) contains supplementary material, which is available to authorized users.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

ALDH1A3 upregulation and spontaneous metastasis formation is associated with acquired chemoresistance in colorectal cancer cells

Background

Efficiency of colorectal carcinoma treatment by chemotherapy is diminished as the resistance develops over time in patients. The same holds true for 5-fluorouracil, the drug used in first line chemotherapy of colorectal carcinoma.

Methods

Chemoresistant derivative of HT-29 cells was prepared by long-term culturing in increasing concentration of 5-fluorouracil. Cells were characterized by viability assays, flow cytometry, gene expression arrays and kinetic imaging. Immunomagnetic separation was used for isolation of subpopulations positive for cancer stem cells-related surface markers. Aldehyde dehydrogenase expression was attenuated by siRNA. In vivo studies were performed on SCID/bg mice.

Results

The prepared chemoresistant cell line labeled as HT-29/EGFP/FUR is assigned with different morphology, decreased proliferation rate and 135-fold increased IC₅₀ value for 5-fluorouracil in comparison to parental counterparts HT-29/EGFP. The capability of chemoresistant cells to form tumor xenografts, when injected subcutaneously into SCID/bg mice, was strongly compromised, however, they formed distant metastases in mouse lungs spontaneously. Derived cells preserved their resistance in vitro and in vivo even without the 5-fluorouracil selection pressure. More importantly, they were resistant to cisplatin, oxaliplatin and cyclophosphamide exhibiting high cross-resistance along with alterations in expression of cancer-stem cell markers such as CD133, CD166, CD24, CD26, CXCR4, CD271 and CD274. We also detected increased aldehyde dehydrogenase (ALDH) activity associated with overexpression of specific ALDH isoform 1A3. Its inhibition by siRNA approach partially sensitized cells to various agents, thus linking for the first time the ALDH1A3 and chemoresistance in colorectal cancer.

Conclusion

Our study demonstrated that acquired chemoresistance goes along with metastatic and migratory phenotype and can be accompanied with increased activity of aldehyde dehydrogenase. We describe here the valuable model to study molecular link between resistance to chemotherapy and metastatic dissemination.

High co-expression of the SDF1/CXCR4 axis in hepatocarcinoma cells is regulated by AnnexinA7 in vitro and in vivo

BACKGROUND

SDF1/CXCR4 and AnnexinA7 play important roles in many physiological and pathological conditions, but the molecular association between them in cancer cells has not been studied thus far.

METHODS

The expression changes of SDF1/CXCR4 were detected by gene transcriptome sequencing, qRT-PCR, Western blotting, cytoimmunofluorescence and immunohistochemistry in mouse hepatocarcinoma F/P cells, AnnexinA7 downregulated expression F (FA7DOWN) cells, AnnexinA7 overexpression P (PA7UP) cells, AnnexinA7 unrelated sequence F (FSHUS) cells, empty vector P (PNCEV) cells and normal liver cells in vitro and in vivo.

RESULTS

SDF1 and CXCR4 were co-expressed in hepatocarcinoma cells. SDF1 was localized mainly in the cytoplasm of cells, while CXCR4 was mainly localized in the cell membrane. Both in vitro and in vivo, expression levels of SDF1/CXCR4 in F and P cells were higher than in normal liver cells, and expression levels of SDF1/CXCR4 in F cells with high lymphatic metastatic potential were higher than those in P cells with low lymphatic metastatic potential. Expression of SDF1 was higher than that of CXCR4 in P cells and normal liver cells, while expression of CXCR4 was higher than that of SDF1 in F cells. Expression levels of SDF1/CXCR4 were completely consistent with AnnexinA7 regulation. After the AnnexinA7 gene was downregulated or upregulated, expression levels of SDF1/CXCR4 in FA7DOWN/PA7UP cells were lower or higher than those in FSHUS/PNCEV cells. Furthermore, CXCR4 was more sensitively modulated by AnnexinA7 regulation than SDF1.

CONCLUSIONS

High co-expression of SDF1/CXCR4 is a molecular characteristic of hepatocarcinoma cells, especially those with high lymphatic metastatic potential. AnnexinA7 positively regulates expression levels of SDF1/CXCR4, in particular CXCR4, and AnnexinA7 is a functional regulator of SDF1/CXCR4.

CXCR4 overexpression is correlated with poor prognosis in colorectal cancer

AIMS

Colorectal cancer threatens human health due to its high mortality resulting from metastatic progression. The expression of C-X-C chemokine receptor type 4 (CXCR4) is absent or low in most healthy tissues but high in various types of tumours. In this study, we aim to determine the prognostic significance of CXCR4 in colorectal cancer.

MAIN METHODS

We retrospectively examined a total of 72 tissue samples, that qRT-PCR and immunohistochemistry were performed to detect the expression of CXCR4 as well as univariate and multivariate analyses were performed to explore the overall survival.

KEY FINDINGS

Our data demonstrated that CXCR4 expression was associated with lymph node metastasis (P = 0.049), histological differentiation (P = 0.01), distant metastasis (P = 0.02) and DNA mismatch repair (MMR) index (P = 0.0002). However, CXCR4 expression was not associated with age, sex, tumour diameter or depth of invasion. Furthermore, both univariate and multivariate analyses confirmed that CXCR4 was an independent factor in predicting unfavourable overall survival (hazard ratio, 0.188; 95% confidence interval, 0.038-0.757).

SIGNIFICANCE

In conclusion, our findings suggest that CXCR4 might contribute to clinical tumour progression and may be a valuable prognostic biomarker in colorectal cancer treatment.

Role of the stromal cell derived factor-1/CXC chemokine receptor 4 axis in the invasion and metastasis of lung cancer and mechanism

Background

Lung cancer is the most common tumor, and has the highest incidence and mortality rates among all malignant tumors. Since stromal cell derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) are specific to binding sites, they are more important than other members of the families for tumor invasion and metastasis. We herein aimed to investigate the role of the axis of chemokine SDF-1 and its receptor CXCR4 in the invasion and metastasis of lung cancer.

Methods

Sixty clinical non-small cell lung cancer (NSCLC) tissue samples were collected. The CXCR4 expressions in cancer, paracancerous and normal lung tissues were detected by immunocytochemical assay and PCR. Cells with CXCR4 overexpression (CXCR4-A549) were constructed. After induction with SDF-1, CXCR4-A549 and A549 cells were subjected to in vitro chemotaxis and invasion assays. Their proliferation and apoptosis were detected by flow cytometry. The activities of phosphoinositide 3-kinase/protein kinase B (AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)-related signaling pathways were detected by Western blot. The downstream signaling molecules that may be activated by SDF-1/CXCR4 were analyzed. The expressions of vascular endothelial growth factor-C and matrix metalloproteinase-2 were detected by Western blot and PCR. A mouse model was established by subcutaneous inoculation of lung cancer cells. The effects of up-regulated CXCR4 expression on the migration of lung cancer cells in vitro and their tumorigenesis and metastasis in vivo were assessed.

Results

There was no expression in normal or paracancerous tissues. The expression of CXCR4 mRNA in lung cancer tissues was 83.3% (50/60). The expressions of CXCR4 in lung squamous cell carcinoma and adenocarcinoma were similar (P>0.05). The expression of CXCR4 was 76.9% (10/13) in highly differentiated carcinoma, 82.1% (23/28) in moderately differentiated carcinoma and 84.2% (16/19) in lowly differentiated carcinoma (P>0.05). The expression of CXCR4 was 72.7% (8/11) in TNM stage I patients, 83.9% (26/31) in stage II patients, and 88.9% (16/18) in stage III patients, with significant correlations. After up-regulation of CXCR4, the invasion ability of CXCR4-A549 cells was increased 1.62-fold (P<0.05). ERK and AKT were significantly phosphorylated 30 min after SDF-1 treatment. The tumorigenic rates of six mice inoculated with CXCR4-A549 and A549 cells were both 100%, with the average tumor weights of (4.37±0.96 g) and (3.24±1.16 g) respectively (P<0.05). In the CXCR4-A549 group, metastatic tumors clearly formed in the lungs of 6 mice, but only 2 mice in the A549 group had tumor cell invasion.

Conclusions

SDF-1/CXCR4 played a key role in the invasion and metastasis of lung cancer. The interaction between SDF-1α and CXCR4 activated a series of downstream molecules by activating ERK and AKT.

Tumacrophage: macrophages transformed into tumor stem-like cells by virulent genetic material from tumor cells

Tumor-associated macrophages are regarded as tumor-enhancers as they have key roles in the subversion of adaptive immunity and in inflammatory circuits that promote tumor progression. Here, we show that cancer cells can subvert macrophages yielding cells that have gained pro-tumor functions. When macrophages isolated from mice or humans are co-cultured with dead cancer cell line cells, induced to undergo apoptosis to mimic chemotherapy, up-regulation of pro-tumor gene expression was identified. Phagocytosis of apoptotic cancer cells by macrophages resulted in their transformation into tumor stem (initiating)-like cells, as indicated by the expression of epithelial markers (e.g., cytokeratin) and stem cell markers (e.g., Oct4) and their capability to differentiate in vitro and self-renew in serum-free media. Moreover, we identified a subset of monocytes/macrophages cells in the blood of cancer (breast, ovarian and colorectal) patients undergoing chemotherapy that harbor tumor transcripts. Our findings uncover a new role for macrophages in tumor development, where they can be transformed into tumor-like cells, potentially by horizontal gene transfer of tumor-derived genes, thus, by taking advantage of chemotherapy, these transformed macrophages promote tumor metastasis by escaping immune surveillance.

A meta-analysis of CXCL12 expression for cancer prognosis

Background:

CXCL12 (SDF1) is reported to promote cancer progression in several preclinical models and this is corroborated by the analysis of human tissue specimens. However, the relationship between CXCL12 expression and cancer survival has not been systematically assessed.

Methods:

We conducted a systematic review and meta-analysis of studies that evaluated the association between CXCL12 expression and cancer survival.

Results:

Thirty-eight studies inclusive of 5807 patients were included in the analysis of overall, recurrence-free or cancer-specific survival, the majority of which were retrospective. The pooled hazard ratios (HRs) for overall and recurrence-free survival in patients with high CXCL12 expression were 1.39 (95% CI: 1.17–1.65, P=0.0002) and 1.12 (95% CI: 0.82–1.53, P=0.48) respectively, but with significant heterogeneity between studies. On subgroup analysis by cancer type, high CXCL12 expression was associated with reduced overall survival in patients with oesophagogastric (HR 2.08; 95% CI: 1.31–3.33, P=0.002), pancreatic (HR 1.54; 95% CI: 1.21–1.97, P=0.0005) and lung cancer (HR 1.37; 95% CI: 1.08–1.75, P=0.01), whereas in breast cancer patients high CXCL12 expression conferred an overall survival advantage (HR 0.5; 95% CI: 0.38–0.66, P<0.00001).

Conclusions:

Determination of CXCL12 expression has the potential to be of use as a cancer biomarker and adds prognostic information in various cancer types. Prospective or prospective–retrospective analyses of CXCL12 expression in clearly defined cancer cohorts are now required to advance our understanding of the relationship between CXCL12 expression and cancer outcome.