Therapeutic Suppression of FAK-AKT Signaling Overcomes Resistance to SHP2 Inhibition in Colorectal Carcinoma

Inhibition of Integrin-Associated Kinases FAK and ILK on the In Vitro Model of Skin Wound Healing

Dermal fibroblasts are essential cells of skin tissue responsible for its normal functioning. In skin wounds, the differentiation of resident fibroblasts into myofibroblasts occurs, which is accompanied by the rearrangement of actin cytoskeleton with the expression of alpha-smooth muscle actin. This transformation is a prerequisite for a successful wound healing. At the same time, different studies indicate that extracellular matrix may be involved in regulation of this process. Since the connection between cells and matrix is provided by transmembrane integrin receptors, this work was aimed at studying the dynamics of signaling pathways associated with integrins on an in vitro model of wound healing using human skin fibroblasts. It was shown that the healing of simulated wound was accompanied by a change in the level of integrins as well as integrin-associated kinases ILK (integrin-linked kinase) and FAK (focal adhesion kinase). Pharmacological inhibition of ILK and FAK caused the suppression of p38 and Akt which proteins are involved in regulation of the actin cytoskeleton. Moreover, it resulted in an inefficient wound closure in vitro. The results of this study support the involvement of integrin-associated kinases in regulation of fibroblast-to-myofibroblast transition during wound healing.

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.

SULF1 regulates malignant progression of colorectal cancer by modulating ARSH via FAK/PI3K/AKT/mTOR signaling

BACKGROUND

Colorectal cancer (CRC) has the third highest incidence and second mortality rate of malignant tumors globally, highlighting the urgency to explore the mechanisms underlying CRC progression for refined treatment of this patient population.

METHODS

R Studio was used for data sorting and analysis. Cell apoptosis and cell cycle detection were performed by flow cytometry. Quantitative real-time PCR (qRT-PCR) was used to explore mRNA expression levels. Western blotting was used to explore protein expression levels. CCK8, EdU, and colony formation assays were performed to explore the proliferation capacity of CRC cells. Transwell invasion and migration assays, along with the wound healing assay, were used to explore the invasive and migratory abilities of CRC cells. Subcutaneous Xenograft Assay was utilized to evaluate the tumorigenic capacity of CRC cells in vivo.

RESULTS

SULF1 was highly expressed in CRC samples and cell lines. The knockdown of SULF1 inhibited the proliferation, invasion, and migration of CRC and increased the rate of cell apoptosis. Meanwhile, we demonstrated that SULF1 could negatively regulate ARSH through the FAK/PI3K/AKT/mTOR pathway.

CONCLUSION

We demonstrated that SULF1 could promote CRC progression by regulating ARSH. The SULF1/ARSH/FAK/PI3K/AKT/mTOR signaling pathway represents a promising target for the treatment of this patient population. Colorectal cancer (CRC) has the third highest incidence and second mortality rate of malignant tumors globally. Sulfatase 1 (SULF1) belongs to the sulfatase family, The function of SULF1 in CRC remains elusive. Our study demonstrated that the knockdown of SULF1 could inhibit the proliferation, invasion, and migration of CRC. Meanwhile, our findings indicated that SULF1 could interact with Arylsulfatase Family Member H (ARSH) to regulate the proliferation, invasion, and migration of CRC via the FAK/PI3K/AKT/mTOR signaling pathway. Taken together, our findings suggest that SULF1 might be a new therapeutic target in CRC.

The novel angiogenesis regulator circFAM169A promotes the metastasis of colorectal cancer through the angiopoietin-2 signaling axis

BACKGROUND

Angiogenesis plays an important role in the metastasis of cancers. However, the mechanisms whereby circular RNAs (circRNAs) regulate angiogenesis and affect cancer metastasis are still unclear.

METHODS

We used gene set variation and Spearman's correlation analyses to identify novel angiogenesis-related circRNAs, including circFAM169A. The Kyoto Encyclopedia of Genes and Genomes and Gene Ontology were used to assess the potential biological function of circFAM169A. A quantitative reverse transcription-PCR (qRT-PCR) analysis of 20 pairs of colorectal cancer (CRC) samples was performed to detect the expression level of circFAM169A. Transwell assays, tube formation assays, and nude mouse metastatic tumor models were used to study the function of circFAM169A in CRC. qRT-PCR, dual-luciferase reporter gene assay, RNA antisense purification assay, and Western blot were performed to analyze the competing endogenous RNA mechanism of circFAM169A in promoting CRC angiogenesis.

RESULTS

circFAM169A was highly correlated with the hallmark of angiogenesis in CRC patients. It was up-regulated in liver metastasized CRC patients. circFAM169A overexpression promoted the angiogenesis, migration, and invasion of CRC cells while its down-regulation had the opposite effects. In vivo mouse models further highlighted the pro-metastatic role of circFAM169A in CRC. More importantly, we discovered that circFAM169A enhances the expression of angiopoietin-2 by binding to miR-518a-5p.