The tyrosine phosphatase SHP2 promotes proliferation and oxaliplatin resistance of colon cancer cells through AKT and ERK

Discovery of novel phenyl urea SHP2 inhibitors with anti-colon cancer and potential immunomodulatory effects

Src Homology-2 Domain Containing Protein Tyrosine Phosphatase-2 (SHP2) is a non-receptor-type protein tyrosine phosphatase (PTP), which is recognized as potential and attractive cancer therapeutic target. Currently, no SHP2 inhibitors have been approved for clinical use, and colorectal cancer (CRC) cells exhibited frequent resistance to reported SHP2 inhibitors, such as SHP099 and TNO155. Herein, we reported our discovery and optimization of phenyl urea as novel SHP2 inhibitors. A8, the most potential SHP2 inhibitor, exhibited great antiproliferative activities against SHP099/TNO155-insensitive tumor cell lines, and rescued PD-L1-mediated immunosuppression. A8 significantly suppressed in vivo tumor growth in a CT26 mouse model and activated immunomodulatory effects in tumor microenvironment. Our work demonstrated that A8 has the potential to be a lead compound for the further development of SHP2 inhibitor and the treatment of CRC.

Exosomes Mediate the Production of Oxaliplatin Resistance and Affect Biological Behaviors of Colon Cancer Cell Lines

BACKGROUND

Colon cancer has high mortality rate which making it one of the leading causes of cancer deaths. Oxaliplatin is a common chemotherapeutic drug, but it has disadvantages such as drug resistance.

OBJECTIVE

The purpose of this study is to explore the mechanism of exosomes in the resistance of oxaliplatin and verify whether elemene and STAT3 inhibitors reverse the resistance to oxaliplatin.

METHODS

Related cell line models were constructed and the proliferation, migration, invasion, apoptosis and resistance to oxaliplatin were evaluated for all three cells of HCT116/L, sensitive cell HCT116 and HCT116+HCT116/L-exosomes (HCT116-exo). It was to explore probable signaling pathways and mechanisms by Western blotting.

RESULTS

HCT116-exo drug-resistant chimeric cells showed greater capacity for proliferation, migration and invasion than HCT116 sensitive cells. After the above cells were treated with oxaliplatin, the apoptosis rate of chimeric drug-resistant cells HCT116-exo and its IC50 increased compared with the sensitive cells HCT116. The proliferation, invasion and migration of cells treated with STAT3 inhibitor or β-elemene combined with oxaliplatin reduced compared with those treated with oxaliplatin or β-elemene alone. The STAT3 inhibitor or β-elemene in combination with oxaliplatin increased the rate of apoptosis relative to oxaliplatin or β-elemene alone. Drug-resistant cell exosomes could promote the EMT process, related to the participation of FGFR4, SHMT2 and STAT3 inhibitors.

CONCLUSION

Drug-resistant cell exosomes could induce resistance, and improve the capacity of colon cancer towards proliferate, invade, migrate and promote the EMT process. The β-elemene combined with oxaliplatin could reverse the above results which might be related to the STAT3 pathway and EMT pathway in colon cancer.

Neoplastic ICAM-1 protects lung carcinoma from apoptosis through ligation of fibrinogen

Intercellular cell adhesion molecule-1 (ICAM-1) is frequently overexpressed in non-small cell lung cancer (NSCLC) and associated with poor prognosis. However, the mechanism underlying the negative effects of neoplastic ICAM-1 remains obscure. Herein, we demonstrate that the survival of NSCLC cells but not normal human bronchial epithelial cells requires an anti-apoptosis signal triggered by fibrinogen γ chain (FGG)-ICAM-1 interaction. ICAM-1-FGG ligation preserves the tyrosine phosphorylation of ICAM-1 cytoplasmic domain and its association with SHP-2, and subsequently promotes Akt and ERK1/2 activation but suppresses JNK and p38 activation. Abolishing ICAM-1-FGG interaction induces NSCLC cell death by activating caspase-9/3 and significantly inhibits tumor development in a mouse xenograft model. Finally, we developed a monoclonal antibody against ICAM-1-FGG binding motif, which blocks ICAM-1‒FGG interaction and effectively suppresses NSCLC cell survival in vitro and tumor growth in vivo. Thus, suppressing ICAM-1-FGG axis provides a potential strategy for NSCLC targeted therapy.

WWP1 inhibition increases SHP2 inhibitor efficacy in colorectal cancer

Protein tyrosine phosphatase SHP2 activates RAS signaling, which is a novel target for colorectal cancer (CRC) therapy. However, SHP2 inhibitor monotherapy is ineffective for metastatic CRC and a combination therapy is required. In this study, we aimed to improve the antitumor efficacy of SHP2 inhibition and try to explore the resistance mechanism of SHP2 inhibitor. Results showed that WWP1 promoted the proliferation of CRC cells. Genetic or pharmacological inhibition of WWP1 enhanced the effect of SHP2 inhibitor in suppressing tumor growth in vitro and in vivo. WWP1 may mediate feedback reactivation of AKT signaling following SHP2 inhibition. Furthermore, nomogram models constructed with IHC expression of WWP1 and SHP2 greatly improved the accuracy of prognosis prediction for patients with CRC. Our findings indicate that WWP1 inhibitor I3C can synergize with SHP2 inhibitor and is expected to be a new strategy for clinical trials in treating advanced CRC patients.

The Toxoplasma secreted effector TgWIP modulates dendritic cell motility by activating host tyrosine phosphatases Shp1 and Shp2

The obligate intracellular parasite Toxoplasma gondii causes life-threatening toxoplasmosis to immunocompromised individuals. The pathogenesis of Toxoplasma relies on its swift dissemination to the central nervous system through a 'Trojan Horse' mechanism using infected leukocytes as carriers. Previous work found TgWIP, a protein secreted from Toxoplasma, played a role in altering the actin cytoskeleton and promoting cell migration in infected dendritic cells (DCs). However, the mechanism behind these changes was unknown. Here, we report that TgWIP harbors two SH2-binding motifs that interact with tyrosine phosphatases Shp1 and Shp2, leading to phosphatase activation. DCs infected with Toxoplasma exhibited hypermigration, accompanying enhanced F-actin stress fibers and increased membrane protrusions such as filopodia and pseudopodia. By contrast, these phenotypes were abrogated in DCs infected with Toxoplasma expressing a mutant TgWIP lacking the SH2-binding motifs. We further demonstrated that the Rho-associated kinase (Rock) is involved in the induction of these phenotypes, in a TgWIP-Shp1/2 dependent manner. Collectively, the data uncover a molecular mechanism by which TgWIP modulates the migration dynamics of infected DCs in vitro.

Circular RNA circHIPK2 inhibits colon cancer cells through miR-373-3p/RGMA axis

Circular RNAs (circRNAs) have been implicated in cancer development. However, their regulation, function, and underlying mechanisms of action remain unclear. We found that circHIPK2 was downregulated in colon cancer, and low expression levels of circHIPK2 were associated with high tumor grade and poor patient survival. The expression of circHIPK2 was observed to be regulated by the transcription factor HOXD10, which was downregulated in colon cancer. Consequently, low circHIPK2 expression promoted colon cancer cell proliferation, migration, and invasion in vitro and tumor growth and metastasis in vivo. Mechanistically, circHIPK2 sponges miR-373-3p to upregulate the expression of the tumor suppressor RGMA, leading to the activation of BMP/Smad signaling and, ultimately, the inhibition of colon cancer cells, indicating that circHIPK2 inhibits colon cancer cells through the miR-373-3p/RGMA/BMP pathway. These findings revealed a previously unknown regulation, function, and underlying mechanism of circHIPK2 in cancer cells. Hence, circHIPK2 may have a prognostic value and serve as a potential target for colon cancer treatment.

M-CSF secreted by gastric cancer cells exacerbates the progression of gastric cancer by increasing the expression of SHP2 in tumor-associated macrophages

OBJECTIVE

To investigate the effect of Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) in tumor-associated macrophages (TAMs), which is mediated by macrophage colony-stimulating factor (M-CSF) secreted by gastric cancer cells, on the development of gastric cancer and its molecular mechanism.

METHODS

The progression of gastric cancer was detected by nude mouse tumor-bearing experiments. Colony formation assay and cell counting kit-8 (CCK8) assay were used to detect the proliferation capacity of gastric cancer cells. The migration capacity of gastric cancer cells was examined by wound healing assay. Transwell migration and invasion assays were performed on gastric cancer cells. Detection of relevant protein expression using western blotting.

RESULTS

Overexpression of SHP2 could promote the progression of gastric cancer in nude mice. The results of colony formation assay and CCK8 assay showed that overexpression of SHP2 could enhance the proliferation of gastric cancer cells. It was found by wound healing assay and Transwell assay that overexpression of SHP2 could facilitate the migration and invasion of gastric cancer cells. The results of Western blotting revealed that overexpression of SHP2 could increase the expressions of p-STAT3, s-PD-1, p-Src, p-Lyn, p-PI3K, p-AKT, Arginase-1, MMP1 and MMP3 but decrease the expressions of TBK1 and SOCS1 in TAMs, and also increase the expressions of CD9, TSG101 and s-PD-1 in exosomes.

CONCLUSION

M-CSF secreted by gastric cancer cells can promote the proliferation, invasion and migration of gastric cancer cells by increasing the expression of SHP2 in TAMs.

Silencing LY6D Expression Inhibits Colon Cancer in Xenograft Mice and Regulates Colon Cancer Stem Cells' Proliferation, Stemness, Invasion, and Apoptosis via the MAPK Pathway

This study explored the role of lymphocyte antigen 6 family member D (LY6D) in colon cancer stem cells' (CCSCs) proliferation and invasion. LY6D was knocked down using siRNA, and the down-regulation of LY6D was verified using Western blotting. After LY6D knockdown, CCSCs' proliferation, stemness, and invasion were suppressed, whereas apoptosis was increased. Gene Ontology (GO) enrichment analysis revealed that the differentially expressed genes (DEGs) between siLY6D and the negative control groups were significantly enriched in the cell-substrate adherens junction, focal adhesion, and cell-substrate junction terms. Meanwhile, the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the DEGs were significantly enriched in the MAPK pathway. In addition, Western blotting results showed that pBRAF and pERK1/2, cascade kinases of the MAPK pathway, were significantly down-regulated after LY6D knockdown. In addition, nude mice xenograft experiments showed that the siLY6D treatment decreased tumor sizes and weights and improved tumor-bearing mice survival rates compared with the control group. In conclusion, these findings indicate that LY6D, which is highly expressed in CCSCs, is a key factor involved in tumor growth and development and might be a potential cancer marker and therapeutic target for colon cancer.

FOXA1/MND1/TKT axis regulates gastric cancer progression and oxaliplatin sensitivity via PI3K/AKT signaling pathway

BACKGROUND

Drug resistance is a main factor affecting the chemotherapy efficacy of gastric cancer (GC), in which meiosis plays an important role. Therefore, it is urgent to explore the effect of meiosis related genes on chemotherapy resistance.

METHODS

The expression of meiotic nuclear divisions 1 (MND1) in GC was detected by using TCGA and clinical specimens. In vitro and in vivo assays were used to investigate the effects of MND1. The molecular mechanism was determined using luciferase reporter assay, CO-IP and mass spectrometry (MS).

RESULTS

Through bioinformatics, we found that MND1 was highly expressed in platinum-resistant samples. In vitro experiments showed that interference of MND1 significantly inhibited the progression of GC and increased the sensitivity to oxaliplatin. MND1 was significantly higher in 159 GC tissues in comparison with the matched adjacent normal tissues. In addition, overexpression of MND1 was associated with worse survival, advanced TNM stage, and lower pathological grade in patients with GC. Further investigation revealed that forkhead box protein A1 (FOXA1) directly binds to the promoter of MND1 to inhibit its transcription. CO-IP and MS assays showed that MND1 was coexpressed with transketolase (TKT). In addition,TKT activated the PI3K/AKT signaling axis and enhanced the glucose uptake and lactate production in GC cells.

CONCLUSIONS

Our results confirm that FOXA1 inhibits the expression of MND1, which can directly bind to TKT to promote GC progression and reduce oxaliplatin sensitivity through the PI3K/AKT signaling pathway.

SH2 Domain-Containing Phosphatase-SHP2 Attenuates Fibrotic Responses through Negative Regulation of Mitochondrial Metabolism in Lung Fibroblasts

Background: We have previously shown that SHP2 downregulation may predispose fibroblasts to differentiate into myofibroblasts and proposed a role for SHP2 downregulation in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Recent data have shown that SHP2 localizes to the mitochondrial intercristae, and its overexpression enhances mitochondrial metabolism leading to oxidative stress and senescence. Objective: To determine the effect of SHP2 on fibrotic responses. Methods and Results: Primary mouse lung fibroblasts derived from mice carrying a conditional knock-in mutation (D61G/+), rendering the SHP2 catalytic domain constitutively active, had reduced proliferation (1.6-fold, p < 0.05), migration (2-fold, p < 0.05), as well as reduced responsiveness of TGFB-1 induced fibroblasts-to-myofibroblasts differentiation, compared to wild-type ones. Electron microscope analysis revealed that SHP2 D61G/+ mouse lung fibroblasts were characterized by mitochondrial abnormalities, including swollen mitochondria with disrupted electron-lucent cristae and an increased number of autophagosomes compared to wild-type ones. SHP2 D61G/+ MLFs exhibited increased protein levels of autophagy markers, including LC3B-II and p-62, evidence that was confirmed by immunofluorescence analysis. Mitochondrial function analysis revealed that stable (genotype D61G/+) overexpression of SHP2 led to impaired mitochondrial function, as assessed by decreased mitochondrial membrane potential (1.29-fold, p < 0.05), coupling efficiency (1.82 fold, p < 0.05), oxygen consumption rate (1.9-fold, p < 0.05), and increased reactive oxygen species production both at baseline (1.75-fold, p < 0.05) and following H2O2 stimulation (1.63-fold, p < 0.05) compared to wild-type ones (SHP2+/+). SHP2 D61G/+ mouse lung fibroblasts showed enhanced AMPK activity, as well as decreased activation of the mTORC1 signaling pathway, potentially leading to ineffective mitochondrial metabolism and increased autophagy. Conclusions: SHP2 attenuates fibrotic responses in fibroblast cell lines through negative regulation of mitochondrial metabolism and induction of autophagy. SHP2 activation may represent a promising therapeutic strategy for patients with fibrotic lung diseases.

XBP1s acts as a transcription factor of IRE1α and promotes proliferation of colon cancer cells

Upon ER stress, IRE1α is activated to splice XBP1 mRNA to generate XBP1s, a transcription factor that induces the expression of genes to cope with the stress. Expression of IRE1α is elevated in cancers and the IRE1α-XBP1s axis plays an important role in proliferation of cancer cells. However, the underlying mechanism is not well known. We found that ER stressors induced the expression of IRE1α, which was inhibited by depletion of XBP1s. XBP1s bound IRE1α promoter and initiated the transcription of IRE1α. These data indicate that XBP1s acts as a transcription factor of IRE1α. Overexpression of XBP1s increased the phosphorylation of JNK, a substrate of IRE1α kinase, which was inhibited by IRE1α kinase inhibitor Kira8. Overexpression of XBP1s also activated the regulated IRE1-dependent decay of mRNAs, which was suppressed by IRE1α RNase inhibitor STF083010. Moreover, we found that expression of XBP1s promoted proliferation of colon cancer cells, which was abrogated by Kira8 and STF083010. The results suggest that XBP1s functions to induce IRE1α expression and promote cancer cell proliferation. Our findings reveal a previously unknown mechanism of IRE1α expression by XBP1s and highlight the role of this regulation in proliferation of colon cancer cells, suggesting that IRE1α-targeting is a potential therapeutic strategy for colon cancer.

Echinatin induces reactive oxygen species-mediated apoptosis via JNK/p38 MAPK signaling pathway in colorectal cancer cells

Colorectal cancer (CRC) is a very common and deadly cancer worldwide, and oxaliplatin is used as first-line chemotherapy. However, resistance usually develops, limiting treatment. Echinatin (Ech) is the main component of licorice and exhibits various therapeutic effects on inflammation-mediated diseases and cancer, ischemia/reperfusion, and liver injuries. The present study elucidated the underlying molecular mechanism of Ech-induced apoptosis in both oxaliplatin-sensitive (HT116 and HT29) and -resistant (HCT116-OxR and HT29-OxR) CRC cells. To evaluate the antiproliferative activities of Ech, we performed MTT and soft agar assays. Ech reduced viability, colony size, and numbers of CRC cells. The underlying molecular mechanisms were explored by various flow cytometry analyses. Ech-induced annexin-V stained cells, reactive oxygen species (ROS) generation, cell cycle arrest, JNK/p38 MAPK activation, endoplasmic reticulum (ER) stress, mitochondrial membrane potential depolarization, and multi-caspase activity. In addition apoptosis-, cell cycle-, and ER stress-related protein levels were confirmed by western blotting. Moreover, we verified ROS-mediated cell death by treatment with inhibitors such as N-acetyl-L-cysteine, SP600125, and SB203580. Taken together, Ech exhibits anticancer activity in oxaliplatin-sensitive and -resistant CRCs by inducing ROS-mediated apoptosis through the JNK/p38 MAPK signaling pathway. This is the first study to show that Ech has the potential to treat drug-resistant CRC, providing new directions for therapeutic strategies targeting drug-resistant CRC.

Protein phosphatases regulate the liver microenvironment in the development of hepatocellular carcinoma

The liver is a complicated heterogeneous organ composed of different cells. Parenchymal cells called hepatocytes and various nonparenchymal cells, including immune cells and stromal cells, are distributed in liver lobules with hepatic architecture. They interact with each other to compose the liver microenvironment and determine its characteristics. Although the liver microenvironment maintains liver homeostasis and function under healthy conditions, it also shows proinflammatory and profibrogenic characteristics that can induce the progression of hepatitis and hepatic fibrosis, eventually changing to a protumoral microenvironment that contributes to the development of hepatocellular carcinoma (HCC). According to recent studies, phosphatases are involved in liver diseases and HCC development by regulating protein phosphorylation in intracellular signaling pathways and changing the activities and characteristics of liver cells. Therefore, this review aims to highlight the importance of protein phosphatases in HCC development and in the regulation of the cellular components in the liver microenvironment and to show their significance as therapeutic targets.

Dihydrotanshinone I Inhibits the Proliferation and Growth of Oxaliplatin-Resistant Human HCT116 Colorectal Cancer Cells

Oxaliplatin (OXA) is a first-line chemotherapeutic drug for the treatment of colorectal cancer (CRC), but acquired drug resistance becomes the main cause of treatment failure. Increasing evidence has shown that some natural components may serve as chemoresistant sensitizers. In this study, we discovered Dihydrotanshinone I (DHTS) through virtual screening using a ligand-based method, and explored its inhibitory effects and the mechanism on OXA-resistant CRC in vitro and in vivo. The results showed that DHTS could effectively inhibit the proliferation of HCT116 and HCT116/OXA resistant cells. DHTS-induced cell apoptosis blocked cell cycle in S and G₂/M phases, and enhanced DNA damage of HCT116/OXA cells in a concentration-dependent manner. DHTS also exhibited the obvious inhibition of tumor growth in the HCT116/OXA xenograft model. Mechanistically, DHTS could downregulate the expression of Src homology 2 structural domain protein tyrosine phosphatase (SHP2) and Wnt/β-catenin, as well as conventional drug resistance and apoptosis-related proteins such as multidrug resistance associated proteins (MRP1), P-glycoprotein (P-gp), Bcl-2, and Bcl-xL. Thus, DHTS markedly induces cell apoptosis and inhibits tumor growth in OXA-resistant HCT116 CRC mice models, which can be used as a novel lead compound against OXA-resistant CRC.

A comprehensive review of SHP2 and its role in cancer

Src homology 2-containing protein tyrosine phosphatase 2 (SHP2) is a non-receptor protein tyrosine phosphatase ubiquitously expressed mainly in the cytoplasm of several tissues. SHP2 modulates diverse cell signaling events that control metabolism, cell growth, differentiation, cell migration, transcription and oncogenic transformation. It interacts with diverse molecules in the cell, and regulates key signaling events including RAS/ERK, PI3K/AKT, JAK/STAT and PD-1 pathways downstream of several receptor tyrosine kinases (RTKs) upon stimulation by growth factors and cytokines. SHP2 acts as both a phosphatase and a scaffold, and plays prominently oncogenic functions but can be tumor suppressor in a context-dependent manner. It typically acts as a positive regulator of RTKs signaling with some inhibitory functions reported as well. SHP2 expression and activity is regulated by such factors as allosteric autoinhibition, microRNAs, ubiquitination and SUMOylation. Dysregulation of SHP2 expression or activity causes many developmental diseases, and hematological and solid tumors. Moreover, upregulated SHP2 expression or activity also decreases sensitivity of cancer cells to anticancer drugs. SHP2 is now considered as a compelling anticancer drug target and several classes of SHP2 inhibitors with different mode of action are developed with some already in clinical trial phases. Moreover, novel SHP2 substrates and functions are rapidly growing both in cell and cancer. In view of this, we comprehensively and thoroughly reviewed literatures about SHP2 regulatory mechanisms, substrates and binding partners, biological functions, roles in human cancers, and different classes of small molecule inhibitors target this oncoprotein in cancer.

Critical roles of PTPN family members regulated by non-coding RNAs in tumorigenesis and immunotherapy

Since tyrosine phosphorylation is reversible and dynamic in vivo, the phosphorylation state of proteins is controlled by the opposing roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatase (PTPs), both of which perform critical roles in signal transduction. Of these, intracellular non-receptor PTPs (PTPNs), which belong to the largest class I cysteine PTP family, are essential for the regulation of a variety of biological processes, including but not limited to hematopoiesis, inflammatory response, immune system, and glucose homeostasis. Additionally, a substantial amount of PTPNs have been identified to hold crucial roles in tumorigenesis, progression, metastasis, and drug resistance, and inhibitors of PTPNs have promising applications due to striking efficacy in antitumor therapy. Hence, the aim of this review is to summarize the role played by PTPNs, including PTPN1/PTP1B, PTPN2/TC-PTP, PTPN3/PTP-H1, PTPN4/PTPMEG, PTPN6/SHP-1, PTPN9/PTPMEG2, PTPN11/SHP-2, PTPN12/PTP-PEST, PTPN13/PTPL1, PTPN14/PEZ, PTPN18/PTP-HSCF, PTPN22/LYP, and PTPN23/HD-PTP, in human cancer and immunotherapy and to comprehensively describe the molecular pathways in which they are implicated. Given the specific roles of PTPNs, identifying potential regulators of PTPNs is significant for understanding the mechanisms of antitumor therapy. Consequently, this work also provides a review on the role of non-coding RNAs (ncRNAs) in regulating PTPNs in tumorigenesis and progression, which may help us to find effective therapeutic agents for tumor therapy.

PHD3 inhibits cell proliferation through hydroxylation of PAX2 at proline 9

The oncoprotein transcription factor paired box 2 (PAX2) is aberrantly expressed in cancers, but the underlying mechanism remains elusive. Prolyl hydroxylase 3 (PHD3) hydroxylates the proline residue of HIFα, mediating HIFα degradation. The von Hippel-Lindau protein (pVHL) is an E3 ligase which mediates ubiquitination and degradation of hydroxylated HIFα. PHD3 and pVHL are found to inhibit the expression of PAX2, however, the molecular mechanism is unclear. Here we demonstrate that PHD3 hydroxylates PAX2 at proline 9, which is required for pVHL to mediate PAX2 ubiquitination and degradation. Overexpression of PHD3 enhances prolyl hydroxylation, ubiquitination and degradation of PAX2 with little effect on those of PAX2(P9A). PHD3 does not influence PAX2 expression in VHL-null cells. pVHL binds to PAX2 and enhances PAX2 ubiquitination and degradation. However, pVHL does not bind with PAX2(P9A) and cannot enhance its ubiquitination and degradation. Our results suggest that proline 9 hydroxylation is a prerequisite for PAX2 degradation by pVHL. Functional studies indicate that introduction of PAX2 into PAX2-null COS-7 cells promotes cell proliferation, which is suppressed by co-expression of PHD3 but not by hydroxylase-deficient PHD3(H196A). PHD3 inhibits PAX2-induced, but not PAX2(P9A)-induced proliferation of COS-7 cells. These results suggest that PHD3 hydroxylates PAX2, followed by pVHL-mediated PAX2 ubiquitination and degradation. This study also suggests that PHD3 inhibits cell proliferation through downregulating PAX2.

The Therapeutic Potential of MAPK/ERK Inhibitors in the Treatment of Colorectal Cancer

The MAPK/ERK signaling pathway regulates cancer cell proliferation, apoptosis, inflammation, angiogenesis, metastasis and drug resistance. Mutations and up-regulation of components of the MAPK/ERK signaling pathway, as well as over-activation of this critical signaling pathway, are frequently observed in colorectal carcinomas. Targeting the MAPK/ERK signaling pathway, using specific pharmacological inhibitors, elicits potent anti-tumor effects, supporting the therapeutic potential of these inhibitors in the treatment of CRC. Several drugs have recently been developed for the inhibition of the MEK/ERK pathway in preclinical and clinical settings, such as MEK162 and MK-2206. MEK1/2 inhibitors demonstrate promising efficacy and anticancer activity for the treatment of this malignancy. This review summarizes the current knowledge on the role of the MAPK/ERK signaling pathway in the pathogenesis of CRC and the potential clinical value of synthetic inhibitors of this pathway in preventing CRC progression for a better understanding, and hence, better management of colorectal cancer.