Activation of c-Met and upregulation of CD44 expression are associated with the metastatic phenotype in the colorectal cancer liver metastasis model

Combined Therapy Targeting MET and Pro-HGF Activation Shows Significant Therapeutic Effect Against Liver Metastasis of CRPC

The liver is the most lethal metastatic site in castration-resistant prostate cancer (CRPC). Overexpression of MET protein has been reported in CRPC, and MET is an important driver gene in androgen-independent CRPC cells. Mouse CRPC cell line CRTC2 was established by subcutaneous injection of hormone-sensitive PC cells (TRAMP-C2) in castrated nude mice. CRCT2/luc2 cells were injected into the spleen of castrated nude mice, and liver metastasis was confirmed at 2 weeks post-injection. We administered MET inhibitor (MET-I) and HGF activator inhibitor (HGFA-I) to this liver metastasis model and assessed the therapeutic effect. After intrasplenic injection, CRTC2 showed a higher incidence of liver metastasis whereas no metastasis was observed in TRAMP-C2. Microarray analysis revealed increased expression of HGF, MET, and HPN, HGFAC (encoding HGF activating proteases) in liver metastasis. Proliferation of CRCT2 was significantly inhibited by co-administration of MET-I and HGFA-I by in vitro analysis with HGF-enriched condition. In an analysis of the mouse model, the combination-therapy group showed the strongest reduction for liver metastasis. Immunohistochemical staining also revealed the strongest decrease in phosphorylation of MET in the combination-therapy group. Co-culture with HGF-expressed mouse fibroblasts showed attenuation of the inhibitory effect of MET-I; however, additional HGFA-I overcame the resistance. We established an androgen-independent CRPC cell line, CRTC2, and liver metastasis model in mice. Significant effect was confirmed by combined treatment of MET-I and HGFA-I by in vitro and in vivo analysis. The results suggested the importance of combined treatment with both MET- and HGF-targeting agents in the treatment of HGF-enriched conditions including liver metastasis.

Coptisine inhibits esophageal carcinoma growth by modulating pyroptosis via inhibition of HGF/c-Met signaling

Esophageal carcinoma is a highly prevalent malignancy worldwide. The present study aimed to investigate the mechanism by which the natural compound coptisine affects pyroptosis in esophageal squamous cell carcinoma (ESCC). The expression of c-Met in ESCC patients was assessed by immunohistochemical analysis of tissue microarrays. Natural drugs that bind to c-Met were identified by screening and molecular docking. The effect of coptisine on the proliferation of ESCC cells was detected by CCK-8 and colony formation assays. Cell cycle progression and cell apoptosis were detected by flow cytometry. The levels of mRNAs related to pyroptosis and miR-21 after coptisine treatment were assessed via real-time quantitative PCR. The effect of pyroptosis was evaluated by reactive oxygen species level detection and transmission electron microscopy (TEM) analysis. The expression of proteins related to pyroptosis and the HGF/c-Met pathway was detected by western blotting. A xenograft tumor model was established, and the inhibitory effect of coptisine was evaluated by observing tumor growth. The results showed that the highly expressed protein c-Met in esophageal cancer could bind with coptisine. Coptisine inhibited c-Met phosphorylation and proliferation in ESCC cells. Furthermore, coptisine inhibited the expression of downstream proteins of the HGF/c-Met signaling pathway and induced ROS generation. Tumor xenograft experiments demonstrated that coptisine effectively inhibited tumor growth by reducing the levels of pyroptosis-associated proteins. In conclusion, these findings indicate that inhibition of the HGF/c-Met signaling pathway suppresses pyroptosis to enhance the antitumor effect of coptisine in ESCC and support the potential use of coptisine for EC treatment.

Formulation, development and evaluation of hyaluronic acid-conjugated liposomal nanoparticles loaded with regorafenib and curcumin and their in vitro evaluation on colorectal cancer cell lines

Colorectal cancer is one of the major causes of global cancer, with chemotherapy and radiation therapy being effective but limited due to low specificity. Regorafenib, a multikinase inhibitor, provides hope to patients with metastatic colorectal cancer and was approved by the FDA in 2012. However, due to resistance issues and adverse events, its efficacy is compromised, necessitating further refinement. Meanwhile, curcumin, a compound of turmeric, exhibits anticancer effects through antioxidant and anti-inflammatory actions, induction of the apoptosis, arrest of cell cycle, inhibition of angiogenesis, and modulation of signaling pathways. Unfortunately, its clinical utility is limited by its poor bioavailability, pointing towards innovative drug delivery strategies for enhanced efficacy in colorectal cancer treatment. Hyaluronic acid (HA)-decorated liposomes (LIPO) have been developed to target colorectal cells through an overexpressed CD44 receptor, increasing antitumor and antimetastasis efficacy. This study investigates the possibility of loading curcumin (CUR) or regorafenib (REGO) into a liposomal formulation for passive and HA-actively targeted treatment, evaluating its critical quality attributes (CQA) (size, zeta potential, polydispersity index) and cytotoxic activity in the HT29 colorectal cancer cell line. The average particle size of the plain liposomes and those decorated with HA was 144.00 ± 0.78 nm and 140.77 ± 1.64 nm, respectively. In contrast, curcumin-loaded plain liposomes and HA-decorated liposomes had 140 ± 2.46 nm and 164.53 ± 15.13 nm, respectively. The prepared liposomes had a spherical shape with a narrow size distribution and an acceptable zeta potential of less than -30 mV. The encapsulation efficiency was 99.2 % ± 0.3 and 99.9 ± 0.2 % for HA-decorated and bare regorafenib loaded. The % EE was 98.9 ± 0.2 % and 97.5 ± 0.2 % for bare liposomal nanoparticles loaded with curcumin and coated with curcumin. The IC50 of free REGO, CUR, REGO-LIPO, CUR-LIPO, REGO-LIPO-HA and CUR-LIPO-HA were 20.17 ± 0.78, 64.4 ± 0.33, 224.8 ± 0.06, 49.66 ± 0.22, 73.66 ± 0.6, and 27.86 ± 0.49 µM, respectively. The MTT assay in HT29 cells showed significant cytotoxic activity of the HA-decorated liposomal formulation compared to the base uncoated formulation, indicating that hyaluronic acid-targeted liposomes loaded with regorafenib or curcumin could be a promising targeted formulation against colorectal cancer cells.

Overexpression of Fatty Acid Synthase Upregulates Glutamine-Fructose-6-Phosphate Transaminase 1 and O-Linked N-Acetylglucosamine Transferase to Increase O-GlcNAc Protein Glycosylation and Promote Colorectal Cancer Growth

Fatty acid synthesis has been extensively investigated as a therapeutic target in cancers, including colorectal cancer (CRC). Fatty acid synthase (FASN), a key enzyme of de novo lipid synthesis, is significantly upregulated in CRC, and therapeutic approaches of targeting this enzyme are currently being tested in multiple clinical trials. However, the mechanisms behind the pro-oncogenic action of FASN are still not completely understood. Here, for the first time, we show that overexpression of FASN increases the expression of glutamine-fructose-6-phosphate transaminase 1 (GFPT1) and O-linked N-acetylglucosamine transferase (OGT), enzymes involved in hexosamine metabolism, and the level of O-GlcNAcylation in vitro and in vivo. Consistently, expression of FASN significantly correlates with expression of GFPT1 and OGT in human CRC tissues. shRNA-mediated downregulation of GFPT1 and OGT inhibits cellular proliferation and the level of protein O-GlcNAcylation in vitro, and knockdown of GFPT1 leads to a significant decrease in tumor growth and metastasis in vivo. Pharmacological inhibition of GFPT1 and OGT leads to significant inhibition of cellular proliferation and colony formation in CRC cells. In summary, our results show that overexpression of FASN increases the expression of GFPT1 and OGT as well as the level of protein O-GlcNAcylation to promote progression of CRC; targeting the hexosamine biosynthesis pathway could be a therapeutic approach for this disease.

RNA four-way junction (4WJ) for spontaneous cancer-targeting, effective tumor-regression, metastasis suppression, fast renal excretion and undetectable toxicity

The field of RNA therapeutics has been emerging as the third milestone in pharmaceutical drug development. RNA nanoparticles have displayed motile and deformable properties to allow for high tumor accumulation with undetectable healthy organ accumulation. Therefore, RNA nanoparticles have the potential to serve as potent drug delivery vehicles with strong anti-cancer responses. Herein, we report the physicochemical basis for the rational design of a branched RNA four-way junction (4WJ) nanoparticle that results in advantageous high-thermostability and -drug payload for cancer therapy, including metastatic tumors in the lung. The 4WJ nanostructure displayed versatility through functionalization with an anti-cancer chemical drug, SN38, for the treatment of two different cancer models including colorectal cancer xenograft and orthotopic lung metastases of colon cancer. The resulting 4WJ RNA drug complex spontaneously targeted cancers effectively for cancer inhibition with and without ligands. The 4WJ displayed fast renal excretion, rapid body clearance, and little organ accumulation with undetectable toxicity and immunogenicity. The safety parameters were documented by organ histology, blood biochemistry, and pathological analysis. The highly efficient cancer inhibition, undetectable drug toxicity, and favorable Chemical, Manufacturing, and Control (CMC) production of RNA nanoparticles document a candidate with high potential for translation in cancer therapy.

Gemcitabine resistance of pancreatic cancer cells is mediated by IGF1R dependent upregulation of CD44 expression and isoform switching

Chemoresistance in pancreatic cancer cells may be caused by the expansion of inherently resistant cancer cells or by the adaptive plasticity of initially sensitive cancer cells. We investigated how CD44 isoforms switching contributed to gemcitabine resistance. Treating CD44 null/low single-cell clones with increasing amounts of gemcitabine caused an increase in expression of CD44 and development of gemcitabine resistant (GR) cells. Drug sensitivity, invasiveness, and EMT process was evaluated by MTT, Matrigel invasion assays, and western blots. Genetic knockdown and pharmacological inhibitors were used to examine the roles of CD44 and IGF1R in mediating gemcitabine resistance. CD44 promoter activity and its interactive EMT-related transcription factors were evaluated by luciferase reporter assay and chromatin immunoprecipitation assay. Kaplan-Meier curve was created by log-rank test to reveal the clinical relevance of CD44 and IGF1R expression in patients. We found silence of CD44 in GR cells partially restored E-cadherin expression, reduced ZEB1 expression, and increased drug sensitivity. The gemcitabine-induced CD44 expressing and isoform switching were associated with an increase in nuclear accumulation of phosphor-cJun, Ets1, and Egr1 and binding of these transcription factors to the CD44 promoter. Gemcitabine treatment induced phosphorylation of IGF1R and increased the expression of phosphor-cJun, Ets1, and Egr1 within 72 h. Stimulation or suppression of IGF1R signaling or its downstream target promoted or blocked CD44 promoter activity. Clinically, patients whose tumors expressed high levels of CD44/IGF1R showed a poor prognosis. This study suggests that IGF1R-dependent CD44 isoform switching confers pancreatic cancer cells to undergo an adaptive change in response to gemcitabine and provides the basis for improved targeted therapy of pancreatic cancer.

Tissue-Specific Downregulation of Fatty Acid Synthase Suppresses Intestinal Adenoma Formation via Coordinated Reprograming of Transcriptome and Metabolism in the Mouse Model of Apc-Driven Colorectal Cancer

Altered lipid metabolism is a potential target for therapeutic intervention in cancer. Overexpression of Fatty Acid Synthase (FASN) correlates with poor prognosis in colorectal cancer (CRC). While multiple studies show that upregulation of lipogenesis is critically important for CRC progression, the contribution of FASN to CRC initiation is poorly understood. We utilize a C57BL/6-Apc/Villin-Cre mouse model with knockout of FASN in intestinal epithelial cells to show that the heterozygous deletion of FASN increases mouse survival and decreases the number of intestinal adenomas. Using RNA-Seq and gene set enrichment analysis, we demonstrate that a decrease in FASN expression is associated with inhibition of pathways involved in cellular proliferation, energy production, and CRC progression. Metabolic and reverse phase protein array analyses demonstrate consistent changes in alteration of metabolic pathways involved in both anabolism and energy production. Downregulation of FASN expression reduces the levels of metabolites within glycolysis and tricarboxylic acid cycle with the most significant reduction in the level of citrate, a master metabolite, which enhances ATP production and fuels anabolic pathways. In summary, we demonstrate the critical importance of FASN during CRC initiation. These findings suggest that targeting FASN is a potential therapeutic approach for early stages of CRC or as a preventive strategy for this disease.

Upregulation of CD36, a Fatty Acid Translocase, Promotes Colorectal Cancer Metastasis by Increasing MMP28 and Decreasing E-Cadherin Expression

Altered fatty acid metabolism continues to be an attractive target for therapeutic intervention in cancer. We previously found that colorectal cancer (CRC) cells with a higher metastatic potential express a higher level of fatty acid translocase (CD36). However, the role of CD36 in CRC metastasis has not been studied. Here, we demonstrate that high expression of CD36 promotes invasion of CRC cells. Consistently, CD36 promoted lung metastasis in the tail vein model and GI metastasis in the cecum injection model. RNA-Seq analysis of CRC cells with altered expression of CD36 revealed an association between high expression of CD36 and upregulation of MMP28, a novel member of the metallopeptidase family of proteins. Using shRNA-mediated knockdown and overexpression of CD36, we confirmed that CD36 regulates MMP28 expression in CRC cells. siRNA-mediated knockdown of MMP28 decreases invasion of CRC cells, suggesting that MMP28 regulates the metastatic properties of cells downstream of CD36. Importantly, high expression of MMP28 leads to a significant decrease in active E-cadherin and an increase in the products of E-cadherin cleavage, CTF1 and CTF2. In summary, upregulation of CD36 expression promotes the metastatic properties of CRC via upregulation of MMP28 and an increase in E-cadherin cleavage, suggesting that targeting the CD36-MMP28 axis may be an effective therapeutic strategy for CRC metastasis.

Targeting Hyaluronic Acid and Peritoneal Dissemination in Colorectal Cancer

Peritoneal metastasis (PM) from colorectal cancer (CRC) carries a significant mortality rate for patients and treatment is challenging. The development of PM is a multistep process involving detachment, adhesion, invasion and colonization of the peritoneal cavity. Cytoreductive surgery and HIPEC (hyperthermic intraperitoneal chemotherapy) for PM from CRC has some benefit but overall survival is poor and recurrence rates are high. Treatments to prevent the development of peritoneal metastasis could have the potential to improve CRC survival and disease-free outcomes. The ability of cancer cells to invade the peritoneum and become established as metastatic tumors is influenced by a multifactorial process. Hyaluronic acid (HA) has been shown to coat the mesothelial cells of the peritoneum and has been demonstrated to be utilized in various malignancies as part of the metastatic process in peritoneal dissemination. CD44, RHAMM (CD168) and ICAM-1 have all been shown to be binding partners for HA. Targeting HA-mediated binding may prevent adhesion to distant sites within the peritoneum through suppression of interaction of these molecules. Here we review the current literature and discuss key molecules involved with PM dissemination, with the potential to target these mechanisms in the delivery of future treatments.

Liver Immune Microenvironment and Metastasis from Colorectal Cancer-Pathogenesis and Therapeutic Perspectives

A drastic difference exists between the 5-year survival rates of colorectal cancer patients with localized cancer and distal organ metastasis. The liver is the most favorable organ for cancer metastases from the colorectum. Beyond the liver-colon anatomic relationship, emerging evidence highlights the impact of liver immune microenvironment on colorectal liver metastasis. Prior to cancer cell dissemination, hepatocytes secrete multiple factors to recruit or activate immune cells and stromal cells in the liver to form a favorable premetastatic niche. The liver-resident cells including Kupffer cells, hepatic stellate cells, and liver-sinusoidal endothelial cells are co-opted by the recruited cells, such as myeloid-derived suppressor cells and tumor-associated macrophages, to establish an immunosuppressive liver microenvironment suitable for tumor cell colonization and outgrowth. Current treatments including radical surgery, systemic therapy, and localized therapy have only achieved good clinical outcomes in a minority of colorectal cancer patients with liver metastasis, which is further hampered by high recurrence rate. Better understanding of the mechanisms governing the metastasis-prone liver immune microenvironment should open new immuno-oncology avenues for liver metastasis intervention.

Liver Tropism in Cancer: The Hepatic Metastatic Niche

The liver is the largest organ in the human body and is prone for cancer metastasis. Although the metastatic pattern can differ depending on the cancer type, the liver is the organ to which cancer cells most frequently metastasize for the majority of prevalent malignancies. The liver is unique in several aspects: the vascular structure is highly permeable and has unparalleled dual blood connectivity, and the hepatic tissue microenvironment presents a natural soil for the seeding of disseminated tumor cells. Although 70% of the liver is composed of the parenchymal hepatocytes, the remaining 30% is composed of nonparenchymal cells including Kupffer cells, liver sinusoidal endothelial cells, and hepatic stellate cells. Recent discoveries show that both the parenchymal and the nonparenchymal cells can modulate each step of the hepatic metastatic cascade, including the initial seeding and colonization as well as the decision to undergo dormancy versus outgrowth. Thus, a better understanding of the molecular mechanisms orchestrating the formation of a hospitable hepatic metastatic niche and the identification of the drivers supporting this process is critical for the development of better therapies to stop or at least decrease liver metastasis. The focus of this perspective is on the bidirectional interactions between the disseminated cancer cells and the unique hepatic metastatic niche.

BNIPL‑2 expression is correlated with the prognosis and regulates the proliferation of colorectal cancer through CD44

Colorectal cancer (CRC) currently leads to many deaths worldwide. The regulatory mechanism, however, remains largely unclear. In the present study, bioinformatics methods were used to identify genes associated with CRC prognosis and to detect the molecular signals regulating the cell cycle in two CRC cell lines. It was revealed that BNIPL-2 expression was higher in CRC tissues than in adjacent tissue samples. Upregulation of BNIPL-2 was correlated with poor prognosis and the adverse malignant stages T and M. BNIPL-2 was also associated with signaling pathways involved in cancer cell growth. BNIPL-2 overexpression promoted cell proliferation and increased the proportion of cells in the G2/M phase. Knockdown of BNIPL-2 inhibited cell proliferation. CD44 was regulated by BNIPL-2 and promoted cell proliferation. Downregulation of CD44 suppressed cell proliferation and rescued the cell proliferation promoted by BNIPL-2. Overexpression of CD44 restored the cell proliferation suppressed by BNIPL-2 knockdown. The present study not only suggested that BNIPL-2 may be a potential biomarker of CRC but also indicated that BNIPL-2 regulates CRC cancer proliferation via CD44, which could be a diagnostic and clinical treatment target.

Human colorectal cancer-derived carcinoma associated fibroblasts promote CD44-mediated adhesion of colorectal cancer cells to endothelial cells by secretion of HGF

BACKGROUND

Carcinoma-associated fibroblasts (CAFs) are dominant components of tumor microenvironment, which has been reported to promote development, progression, and metastasis of cancer. However, the role of CAFs during adhesion process remains unknown. It has been hypothesized that CAFs contribute to adhesion to endothelial cells of colorectal cancer (CRC) via HGF/c-Met pathway.

METHODS

Clinical specimen and orthotopic liver metastasis model was used to investigate association between CD44 expression and propensity of metastasis in CRC. Human CRC derived cancer associated fibroblasts was isolated and its effect on migration and adhesion of CRC cells was investigated. We also confirm the conclusion on animal metastasis model.

RESULTS

In this study, clinical specimen and orthotopic liver metastatic model indicated that overexpression of CD44 is associated with CRC metastasis, and we found that colorectal cancer-derived CAFs (CC-CAFs) increased the adhesion and migration of CRC cells in vitro through up-regulation of CD44, we also found that CC-CAFs promoted adhesion and liver or lung metastasis in vivo. Mechanistically, we found that the expression of HGF increased tenfolds compared CC-CAFs with adjacent normal fibroblasts, and HGF promoted adhesion through up-regulation of CD44 via HGF/c-MET signal pathway.

CONCLUSIONS

These results indicated that CC-CAFs-derived HGF induced up-regulation of CD44 which mediated adhesion of CRC cells to endothelial cells, and subsequently resulted in enhancement of metastasis of CRC cells, it could provide a novel therapeutic or preventive target.

Myoferlin Contributes to the Metastatic Phenotype of Pancreatic Cancer Cells by Enhancing Their Migratory Capacity through the Control of Oxidative Phosphorylation

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies with an overall survival of 5% and is the second cause of death by cancer, mainly linked to its high metastatic aggressiveness. Accordingly, understanding the mechanisms sustaining the PDAC metastatic phenotype remains a priority. In this study, we generated and used a murine in vivo model to select clones from the human Panc-1 PDAC cell line that exhibit a high propensity to seed and metastasize into the liver. We showed that myoferlin, a protein previously reported to be overexpressed in PDAC, is significantly involved in the migratory abilities of the selected cells. We first report that highly metastatic Panc-1 clones expressed a significantly higher myoferlin level than the corresponding low metastatic ones. Using scratch wound and Boyden’s chamber assays, we show that cells expressing a high myoferlin level have higher migratory potential than cells characterized by a low myoferlin abundance. Moreover, we demonstrate that myoferlin silencing leads to a migration decrease associated with a reduction of mitochondrial respiration. Since mitochondrial oxidative phosphorylation has been shown to be implicated in the tumor progression and dissemination, our data identify myoferlin as a valid potential therapeutic target in PDAC.

A genome-wide association study identifies single nucleotide polymorphisms associated with time-to-metastasis in colorectal cancer

Background

Differentiating between cancer patients who will experience metastasis within a short time and who will be long-term survivors without metastasis is a critical aim in healthcare. The microsatellite instability (MSI)-high tumor phenotype is such a differentiator in colorectal cancer, as patients with these tumors are unlikely to experience metastasis. Our aim in this study was to determine if germline genetic variations could further differentiate colorectal cancer patients based on the long-term risk and timing of metastasis.

Methods

The patient cohort consisted of 379 stage I-III Caucasian colorectal cancer patients with microsatellite stable or MSI-low tumors. We performed univariable analysis on 810,622 common single nucleotide polymorphisms (SNPs) under different genetic models. Depending on the long-term metastasis-free survival probability estimates, we applied a mixture cure model, Cox proportional hazards regression model, or log-rank test. For SNPs reaching Bonferroni-corrected significance (p < 6.2 × 10^− 8) having valid genetic models, multivariable analysis adjusting for significant baseline characteristics was conducted.

Results

After adjusting for significant baseline characteristics, specific genotypes of ten polymorphisms were significantly associated with time-to-metastasis. These polymorphisms are three intergenic SNPs, rs5749032 (p = 1.28 × 10^− 10), rs2327990 (p = 9.59 × 10^− 10), rs1145724 (p = 3 × 10^− 8), and seven SNPs within the non-coding sequences of three genes: FHIT (p = 2.59 × 10^− 9), EPHB1 (p = 8.23 × 10^− 9), and MIR7515 (p = 4.87 × 10^− 8).

Conclusions

Our results suggest novel associations of specific genotypes of SNPs with early metastasis in Caucasian colorectal cancer patients. These associations, once replicated in other patient cohorts, could assist in the development of personalized treatment strategies for colorectal cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5346-5) contains supplementary material, which is available to authorized users.

Upregulation of c-mesenchymal epithelial transition expression and RAS mutations are associated with late lung metastasis and poor prognosis in colorectal carcinoma

The present study aimed to investigate whether c-mesenchymal epithelial transition factor (C-MET) overexpression combined with RAS (including KRAS, NRAS and HRAS) or BRAF mutations were associated with late distant metastases and the prognosis of patients with colorectal cancer (CRC). A total of 374 patients with stage III CRC were classified into 4 groups based on RAS/BRAF and C-MET status for comprehensive analysis. Mutations in RAS/BRAF were determined using Sanger sequencing and C-MET expression was examined using immunohistochemistry. The associations between RAS/BRAF mutations in combination with C-MET overexpression and clinicopathological variables including survival were evaluated. In addition, their predictive value for late distant metastases were statistically analyzed via logistic regression and receiver operating characteristic analysis. Among 374 patients, mutations in KRAS, NRAS, HRAS, BRAF and C-MET overexpression were observed in 43.9, 2.4, 0.3, 5.9 and 71.9% of cases, respectively. Considering RAS/BRAF mutations and C-MET overexpression, vascular invasion (P=0.001), high carcino-embryonic antigen level (P=0.031) and late distant metastases (P<0.001) were more likely to occur in patients of group 4. Furthermore, survival analyses revealed RAS/BRAF mutations may have a more powerful impact on survival than C-MET overexpression, although they were both predictive factors for adverse prognosis. Further logistic regression suggested that RAS/BRAF mutations and C-MET overexpression may predict late distant metastases. In conclusion, RAS/BRAF mutations and C-MET overexpression may serve as predictive indicators for metastatic behavior and poor prognosis of CRC.

Fucoidan enhances the therapeutic potential of arsenic trioxide and all-trans retinoic acid in acute promyelocytic leukemia, in vitro and in vivo

The morbidity and mortality associated with current therapies for acute promyelocytic leukemia (APL) remain a significant clinical concern, despite improvements in patient survival. Consequently, the development of adjuvant therapies that increase efficacy while reducing morbidities is important. Reducing the concentration of the toxic drugs in adjuvant therapy has the potential to reduce unwanted side effects. Therefore, this study aimed to determine the synergistic effects of fucoidan, an anti-tumor agent, with current APL therapies.When the human APL cell line, NB4, was treated in vitro with fucoidan plus ATO and ATRA at therapeutic and sub-therapeutic doses, there was an increase in sub-G0/G1 cells, annexin V/PI-positive-apoptotic cells and DNA fragmentation. This reduction in proliferation and increase in apoptosis was accompanied by enhanced myeloid differentiation as indicated by an increased expression of CD11b. This was not observed with the AML cell line Kasumi-1, suggesting specificity for APL.In vivo treatment of APL-bearing mice with fucoidan+ATRA or fucoidan+ATO delayed tumor growth, induced differentiation and increased tumor volume doubling time. The differentiated APL cells derived from the excised tumor mass exhibited decreased CD44 expression in fucoidan+ATRA treated mice. This could translate to decreased cell migration in APL patients.Our findings provide evidence supporting the use of fucoidan as an adjuvant therapeutic agent in the treatment of APL.

Hepatocyte growth factor is a prognostic marker in patients with colorectal cancer: a meta-analysis

Hepatocyte growth factor (HGF) is a crucial factor associated with development, progression and metastasis of colorectal cancer (CRC). However, its prognostic value remains unclear. Thus studies referring to the correlation between HGF and CRC patients’ prognosis were included to explore the role of HGF in CRC. At last nine articles were included. The results showed that the over-expression of HGF was associated with a poor prognosis, presented through overall survival (OS, Hazard ratio (HR) = 2.50, 95% confidence interval (CI): 2.12–2.96) and disease-free survival (DFS, HR = 1.99, 95% CI: 1.59–2.50). Subgroup analysis indicated that no significant difference was found between the Asian countries (OS: HR = 2.37; DFS: HR = 2.02) and the non-Asian countries (OS: HR = 3.15; DFS: HR = 1.87), between the studies that used univariate analyses (OS: HR = 2.51; DFS: HR = 2.07) and those that used multivariate analyses (OS: HR = 2.65; DFS: HR = 1.78), and between metastatic CRC (OS: HR = 2.26; DFS: HR = 2.06) and stage I-IV CRC (OS: HR = 3.08; DFS: HR = 0.70). Our meta-analysis has shown that the over-expression of HGF is valuable in CRC prognosis evaluation. This conclusion should be further confirmed by large-sample cohort studies.

Development of Halofluorochromic Polymer Nanoassemblies for the Potential Detection of Liver Metastatic Colorectal Cancer Tumors Using Experimental and Computational Approaches

PURPOSE

To develop polymer nanoassemblies (PNAs) modified with halofluorochromic dyes to allow for the detection of liver metastatic colorectal cancer (CRC) to improve therapeutic outcomes.

METHODS

We combine experimental and computational approaches to evaluate macroscopic and microscopic PNA distributions in patient-derived xenograft primary and orthotropic liver metastatic CRC tumors. Halofluorochromic and non-halofluorochromic PNAs (hfPNAs and n-hfPNAs) were prepared from poly(ethylene glycol), fluorescent dyes (Nile blue, Alexa546, and IR820), and hydrophobic groups (palmitate), all of which were covalently tethered to a cationic polymer scaffold [poly(ethylene imine) or poly(lysine)] forming particles with an average diameter < 30 nm.

RESULTS

Dye-conjugated PNAs showed no aggregation under opsonizing conditions for 24 h and displayed low tissue diffusion and cellular uptake. Both hfPNAs and n-hfPNAs accumulated in primary and liver metastatic CRC tumors within 12 h post intravenous injection. In comparison to n-hfPNAs, hfPNAs fluoresced strongly only in the acidic tumor microenvironment (pH < 7.0) and distinguished small metastatic CRC tumors from healthy liver stroma. Computational simulations revealed that PNAs would steadily accumulate mainly in acidic (hypoxic) interstitium of metastatic tumors, independently of the vascularization degree of the tissue surrounding the lesions.

CONCLUSION

The combined experimental and computational data confirms that hfPNAs detecting acidic tumor tissue can be used to identify small liver metastatic CRC tumors with improved accuracy.

Molecular weight specific impact of soluble and immobilized hyaluronan on CD44 expressing melanoma cells in 3D collagen matrices

Hyaluronan (HA) and its principal receptor CD44 are known to be involved in regulating tumor cell dissemination and metastasis. The direct correlation of CD44-HA interaction on proliferation and invasion of tumor cells in dependence on the molecular weight and the presentation form of HA is not fully understood because of lack of appropriate matrix models. To address this issue, we reconstituted 3D collagen (Coll I) matrices and functionalized them with HA of molecular weight of 30-50kDa (low molecular weight; LMW-HA) and 500-750kDa (high molecular weight; HMW-HA). A post-modification strategy was applied to covalently immobilize HA to reconstituted fibrillar Coll I matrices, resulting in a non-altered Coll I network microstructure and stable immobilization over days. Functionalized Coll I matrices were characterized regarding topological and mechanical characteristics as well as HA amount using confocal laser scanning microscopy, colloidal probe force spectroscopy and quantitative Alcian blue assay, respectively. To elucidate HA dependent tumor cell behavior, BRO melanoma cell lines with and without CD44 receptor expression were used for in vitro cell experiments. We demonstrated that only soluble LMW-HA promoted cell proliferation in a CD44 dependent manner, while HMW-HA and immobilized LMW-HA did not. Furthermore, an enhanced cell invasion was found only for immobilized LMW-HA. Both findings correlated with a very strong and specific adhesive interaction of LMW-HA and CD44+ cells quantified in single cell adhesion measurements using soft colloidal force spectroscopy. Overall, our results introduce an in vitro biomaterials model allowing to test presentation mode and molecular weight specificity of HA in a 3D fibrillar matrix thus mimicking important in vivo features of tumor microenvironments.

STATEMENT OF SIGNIFICANCE

Molecular weight and presentation form (bound vs. soluble) of hyaluronan (HA) are intensively discussed as key regulators in tumor progression and inflammation. We introduce 3D fibrillar collagen matrices with defined microstructure and stiffness allowing the presentation of specific molecular weight forms of HA in soluble and bound manner. Mimicking in that way important in vivo features of tumor microenvironments, we found that only low molecular weight HA (LMW-HA) in soluble form promoted proliferation of a melanoma cell line (BRO), while it enhanced cell invasion in bound form. The molecular weight specificity of LMW-HA was verified to be CD44 receptor dependent and was correlated to adhesive ligand-receptor interactions in quantitative colloidal force spectroscopy at single cell level.

Role of the Microenvironment in Liver Metastasis: From Pre- to Prometastatic Niches

Liver metastases remain a major barrier to successful management of malignant disease, particularly for cancers of the gastrointestinal tract but also for other malignancies, such as breast carcinoma and melanoma. The ability of metastatic cells to survive and proliferate in the liver is determined by the outcome of complex, reciprocal interactions between tumor cells and different local resident subpopulations, including the sinusoidal endothelium, stellate, Kupffer, and inflammatory cells that are mediated through cell-cell and cell-extracellular matrix adhesion and the release of soluble factors. Cross-communication between different hepatic resident cells in response to local tissue damage and inflammation and the recruitment of bone marrow cells further enhance this intercellular communication network. Both resident and recruited cells can play opposing roles in the progression of metastasis, and the balance of these divergent effects determines whether the tumor cells will die, proliferate, and colonize the new site or enter a state of dormancy. Moreover, this delicate balance can be tilted in favor of metastasis, if factors produced by the primary tumor precondition the microenvironment to form niches of activated resident cells that promote tumor expansion. This review aims to summarize current knowledge on these diverse interactions and the impact they can have on the clinical management of hepatic metastases. Clin Cancer Res; 22(24); 5971-82. ©2016 AACR.

Impact of CD44v6 overexpression on invasion and metastasis of colon cancer SW480 cells

AIM: To investigate the impact of CD44v6 overexpression on the invasion and metastasis of human colon cancer SW480 cells.

METHODS: SW480 cells stably overexpressing CD44v6 (CD44v6 group) and negative control cells (NC group) were developed through lentivirus infection. Transfection efficiency was evaluated by detecting the expression of enhanced green fluorescent protein (EGFP). CD44v6 mRNA levels were determined using quantitative real-time PCR. Localization of the overexpressed protein was observed by immunofluorescence staining of Flag protein. Cell proliferation was determined by cell counting kit (CCK)-8 assay. Cell invasion and metastasis were examined by scratch assay and transwell assay.

RESULTS: EGFP detection indicated that transfection efficiency was close to 100% in both groups. CD44v6 mRNA levels in CD44v6 overexpressing cells were significantly higher than those in the control cells (P < 0.001). The overexpressed CD44v6 protein was mainly localized on the cell membrane. No difference was revealed in cell proliferation between the two groups by CCK-8 assay. Scratch assay showed that the wound healing index was significantly increased in the CD44v6 group compared with the NC group (P < 0.05). Transwell assay showed that the invasion and metastasis index was significantly increased in the CD44v6 group compared with the NC group (P < 0.05), and the index was significantly decreased after the cells in the CD44v6 group were treated with CD44v6 antibody (P < 0.05).

CONCLUSION: Overexpression of CD44v6 significantly enhances the invasion and metastasis ability of SW480 cells.

Expression of CD44 in pancreatic cancer and its significance

BACKGROUND

CD44 is a potentially interesting prognostic marker and therapeutic target in pancreatic cancer. The expression of CD44 has been reported to correlate with poor prognosis of pancreatic cancer in most literatures. The purpose of this study is to investigate the roles of CD44 in pancreatic caner, and their correlation with the prognosis of pancreatic cancer patients.

METHODS

67 pancreatic cancer samples were collected in Xinhua hospital affiliated to Shanghai Jiaotong University dating from Jan 2010 to Dec 2012. Immunohistochemistry was applied to test the expression of CD44 in pancreatic cancer. The clinical data of the patients were collected including their gender, age, the histology and location, lymph node metastasis and so on. The correlation between the CD44 expression and the clinicopathological factors of patients with pancreatic cancer was analyzed by the software SPSS 13.0. We devise and synthesis of effectively interference of shRNA sequence of CD44, which was transefected to the pancreatic cancer cells PANC-1. Colony formation assay, cell migration assays and western blot were performed.

RESULTS

The positive rates of CD44 expression in pancreatic samples were 73.1% (49/67). Univariate analysis showed that there were a significant differences between the CD44 expression and the pancreatic cancer' T staging, TNM staging, lymph node metastasis, the differentiation degree, tumor location (P < 0.05). The Cox proportional hazards model showed that differentiation, CD44 expression and nerve invasion were independent prognostic factors. Knockdown of CD44 expression in pancreatic cancer cells led to decreased cellular proliferation and migration ability, accompanied by downregulation of p-ERK and p-AKT.

CONCLUSION

CD44 were related to the distant metastasis and aggressive malignant behaviors of pancreatic cancer. CD44 may regulate tumorigenesis and cancer metastasis partially via PI3K/AKT or MAPK/ERK regulatory pathway.

Delivery of RNA nanoparticles into colorectal cancer metastases following systemic administration

The majority of deaths from all cancers, including colorectal cancer (CRC), is a result of tumor metastasis to distant organs. To date, an effective and safe system capable of exclusively targeting metastatic cancers that have spread to distant organs or lymph nodes does not exist. Here, we constructed multifunctional RNA nanoparticles, derived from the three-way junction (3WJ) of bacteriophage phi29 motor pRNA, to target metastatic cancer cells in a clinically relevant mouse model of CRC metastasis. The RNA nanoparticles demonstrated metastatic tumor homing without accumulation in normal organ tissues surrounding metastatic tumors. The RNA nanoparticles simultaneously targeted CRC cancer cells in major sites of metastasis, such as liver, lymph nodes, and lung. Our results demonstrate the therapeutic potential of these RNA nanoparticles as a delivery system for the treatment of CRC metastasis.

The miR-199a/Brm/EGR1 axis is a determinant of anchorage-independent growth in epithelial tumor cell lines

In epithelial cells, miRNA-199a-5p/-3p and Brm, a catalytic subunit of the SWI/SNF complex were previously shown to form a double-negative feedback loop through EGR1, by which human cancer cell lines tend to fall into either of the steady states, types 1 [miR-199a(−)/Brm(+)/EGR1(−)] and 2 [miR-199a(+)/Brm (−)/EGR1(+)]. We show here, that type 2 cells, unlike type 1, failed to form colonies in soft agar, and that CD44, MET, CAV1 and CAV2 (miR-199a targets), all of which function as plasma membrane sensors and can co-localize in caveolae, are expressed specifically in type 1 cells. Single knockdown of any of them suppressed anchorage-independent growth of type 1 cells, indicating that the miR-199a/Brm/EGR1 axis is a determinant of anchorage-independent growth. Importantly, two coherent feedforward loops are integrated into this axis, supporting the robustness of type 1-specific gene expression and exemplifying how the miRNA-target gene relationship can be stably sustained in a variety of epithelial tumors.