Expression of ASAP1 and FAK in gastric cancer and its clinicopathological significance

Role and mechanism of NCAPD3 in promoting malignant behaviors in gastric cancer

Background

Gastric cancer (GC) is one of the major malignancies threatening human lives and health. Non-SMC condensin II complex subunit D3 (NCAPD3) plays a crucial role in the occurrence of many diseases. However, its role in GC remains unexplored.

Materials and Methods

The Cancer Genome Atlas (TCGA) database, clinical samples, and cell lines were used to analyze NCAPD3 expression in GC. NCAPD3 was overexpressed and inhibited by lentiviral vectors and the CRISPR/Cas9 system, respectively. The biological functions of NCAPD3 were investigated in vitro and in vivo. Gene microarray, Gene set enrichment analysis (GSEA) and ingenuity pathway analysis (IPA) were performed to establish the potential mechanisms.

Results

NCAPD3 was highly expressed in GC and was associated with a poor prognosis. NCAPD3 upregulation significantly promoted the malignant biological behaviors of gastric cancer cell, while NCAPD3 inhibition exerted a opposite effect. NCAPD3 loss can directly inhibit CCND1 and ESR1 expression to downregulate the expression of downstream targets CDK6 and IRS1 and inhibit the proliferation of gastric cancer cells. Moreover, NCAPD3 loss activates IRF7 and DDIT3 to regulate apoptosis in gastric cancer cells.

Conclusion

Our study revealed that NCAPD3 silencing attenuates malignant phenotypes of GC and that it is a potential target for GC treatment.

ASAP1 Expression in Invasive Breast Cancer and Its Prognostic Role

Breast cancer is a major global health burden with high morbidity and mortality rates. Previous studies have reported that increased expression of ASAP1 is associated with poor prognosis in various types of cancer. This study was conducted on 452 breast cancer patients who underwent surgery at Hanyang University Hospital, Seoul, South Korea. Data on clinicopathological characteristics including molecular pathologic markers were collected. Immunohistochemical staining of ASAP1 expression level were used to classify patients into high and low groups. In total, 452 cases low ASAP1 expression group was associated with significantly worse recurrence-free survival (p = 0.029). In ER-positive cases (n = 280), the low ASAP1 expression group was associated with significantly worse overall survival (p = 0.039) and recurrence-free survival (p = 0.029). In multivariate cox analysis, low ASAP1 expression was an independent significant predictor of poor recurrence-free survival in the overall patient group (hazard ratio = 2.566, p = 0.002) and ER-positive cases (hazard ratio = 4.046, p = 0.002). In the analysis of the TCGA dataset, the low-expression group of ASAP1 protein demonstrated a significantly poorer progression-free survival (p = 0.005). This study reports that low ASAP1 expression was associated with worse recurrence-free survival in invasive breast cancer.

FAK/IL-8 axis promotes the proliferation and migration of gastric cancer cells

Gastric cancer (GC) is one of the most common malignancies in China and is associated with high mortality. The occurrence and development of gastric cancer are related to genetic and environmental factors. Focal adhesion kinase (FAK) is a cytoplasmic nonreceptor protein tyrosine kinase that is activated by the extracellular matrix and growth factors. FAK is highly expressed in cancer and promotes its development by regulating cancer cell proliferation, migration, and angiogenesis. The expression of IL-8 is increased in many types of malignant tumor cells and is linked to their proliferation, migration, invasion, angiogenesis, and EMT. In this study, we found FAK to be essential for the proliferation, migration, and peritoneal metastasis of gastric cancer cells. To examine the molecular regulatory mechanisms of FAK in the peritoneal dissemination of gastric cancer, we performed RNA-seq analysis of MKN-45-FAK-/- and MKN45 cells and demonstrated that IL-8 was downregulated in FAK-deficient cells. Conversely, we confirmed that IL-8 activates FAK activity. We established that IL-8 promotes the proliferation, colony formation, and migration of gastric cancer cells that are partially mediated by FAK. Thus, we propose that an IL-8-FAK-IL-8 positive feedback loop effects the proliferation and migration of gastric cancer cells.

ASAP1 activates the IQGAP1/CDC42 pathway to promote tumor progression and chemotherapy resistance in gastric cancer

Abnormal expression and remodeling of cytoskeletal regulatory proteins are important mechanisms for tumor development and chemotherapy resistance. This study systematically analyzed the relationship between differential expression of cytoskeleton genes and prognosis in gastric cancer (GC). We found the Arf GTP-activating protein ASAP1 plays a key role in cytoskeletal remodeling and prognosis in GC patients. Here we analyzed the expression level of ASAP1 in tissue microarrays carrying 564 GC tissues by immunohistochemistry. The results showed that ASAP1 expression was upregulated in GC cells and can be served as a predictor of poor prognosis. Moreover, ASAP1 promoted the proliferation, migration, and invasion of GC cells both in vitro and in vivo. We also demonstrated that ASAP1 inhibited the ubiquitin-mediated degradation of IQGAP1 and thus enhanced the activity of CDC42. The activated CDC42 upregulated the EGFR-MAPK pathway, thereby promoting the resistance to chemotherapy in GC. Taken together, our results revealed a novel mechanism by which ASAP1 acts in the progression and chemotherapy resistance in GC. This may provide an additional treatment option for patients with GC.

Functional and clinical characteristics of focal adhesion kinases in cancer progression

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and an adaptor protein that primarily regulates adhesion signaling and cell migration. FAK promotes cell survival in response to stress. Increasing evidence has shown that at the pathological level, FAK is highly expressed in multiple tumors in several systems (including lung, liver, gastric, and colorectal cancers) and correlates with tumor aggressiveness and patient prognosis. At the molecular level, FAK promotes tumor progression mainly by altering survival signals, invasive capacity, epithelial-mesenchymal transition, the tumor microenvironment, the Warburg effect, and stemness of tumor cells. Many effective drugs have been developed based on the comprehensive role of FAK in tumor cells. In addition, its potential as a tumor marker cannot be ignored. Here, we discuss the pathological and pre-clinical evidence of the role of FAK in cancer development; we hope that these findings will assist in FAK-based clinical studies.

Clinicopathological Implications of ASAP1 Expression in Hepatocellular Carcinoma

Background: The expression of ArfGAP with SH3 domain ankyrin repeat and PH domain 1 (ASAP1) is increased in various types of cancer, showing potential as a prognostic marker. The clinicopathological implications of ASAP1 expression in patients with hepatocellular carcinoma (HCC) remain unclear. We thus investigated the clinicopathological significance and prognostic effect of ASAP1 expression in HCC patients.

Materials and Methods: ASAP1 expression was assessed in 149 HCC tissue samples using immunohistochemistry (IHC). The associations between ASAP1 expression and clinicopathological characteristics were analyzed. The prognostic effect of ASAP1 expression in patients with HCC was evaluated based on survival analyses and confirmed using a web-based tool.

Results: ASAP1 expression was observed in the cytoplasm of tumor cells. High ASAP1 expression was observed in 89 (59.7%) of 149 cases. High ASAP1 expression was significantly associated with male patients (p = 0.018), higher histological grade (p = 0.013), vessel invasion (p = 0.021), and higher stage (p = 0.020). High ASAP1 expression was associated with shorter overall survival (OS; p = 0.041) and recurrence-free survival (RFS; p = 0.008) based on Kaplan-Meier survival analyses. Web-based analysis using Kaplan-Meier (KM) plotter showed high mRNA ASAP1 expression to be associated with short OS (p = 0.001).

Conclusion: High ASAP1 expression was associated with aggressive clinicopathological characteristics and poor clinical outcomes in patients with HCC. ASAP1 can be considered a prognostic biomarker in HCC patients.

ptk2 and mt2a Genes Expression in Gastritis and Gastric Cancer Patients with Helicobacter pylori Infection

BACKGROUND

ptk2 and mt2a genes contribute to the cell cycle during proliferation and apoptosis, respectively. Designing a case-control study including gastric adenocarcinoma and gastritis patients with and without Helicobacter pylori infection would lead to determinate of the correlations between ptk2 and mt2a genes expression with H. pylori infection in gastric antral epithelial cells.

METHODS

Overall, 50 and 30 gastric antral biopsy samples of gastric cancer (case group) and gastritis (control group) patients were included into study, respectively. All biopsy samples were collected considering the exclusion criteria including patients with a history of consumption of tobacco, alcohol, and anti-H. pylori drugs. Each patient group is divided into with and without H. pylori infection to detect cDNA fold changes of ptk2 and mt2a genes by using Real Time RT PCR. Furthermore, the presence of H. pylori virulence genes was detected directly by using specific primers and simple PCR on cDNA synthesized from total RNA of gastric antral biopsy samples.

RESULTS

A negative correlation was revealed between age and clinical manifestations with the ΔCt value of the ptk2 gene (P < 0.05). The H. pylori iceA1/2 and cagE genes revealed positive and negative correlations with the ΔCt value of the ptk2 gene (P < 0.05), respectively. Furthermore, a weak correlation was detectable between H. pylori babA2/B, oipA, and cagY genes and the ΔCt value of the mt2a gene in gastric antral epithelial cells of patients (P < 0.1).

CONCLUSIONS

The results of the current study opened a view for more investigation on the stunning roles of H. pylori infection in clinical outcomes through mt2a and ptk2 gene expression in gastric antral epithelial cells.

FAK PROTAC Inhibits Ovarian Tumor Growth and Metastasis by Disrupting Kinase Dependent and Independent Pathways

Focal adhesion kinase (FAK) is highly expressed in a variety of human cancers and is a target for cancer therapy. Since FAK kinase inhibitors only block the kinase activity of FAK, they are not highly effective in clinical trials. FAK also functions as a scaffold protein in a kinase-independent pathway. To effectively target FAK, it is required to block both FAK kinase-dependent and FAK-independent pathways. Thus, we tested a new generation drug FAK PROTAC for ovarian cancer therapy, which blocks both kinase and scaffold activity. We tested the efficacy of FAK PROTAC and its parent kinase inhibitor (VS-6063) in ovarian cancer cell lines in vitro by performing cell functional assays including cell proliferation, migration, invasion. We also tested in vivo activity in orthotopic ovarian cancer mouse models. In addition, we assessed whether FAK PROTAC disrupts kinase-dependent and kinase-independent pathways. We demonstrated that FAK PROTAC is highly effective as compared to its parent FAK kinase inhibitor VS-6063 in inhibiting cell proliferation, survival, migration, and invasion. FAK PROTAC not only inhibits the FAK kinase activity but also FAK scaffold function by disrupting the interaction between FAK and its interaction protein ASAP1. We further showed that FAK PROTAC effectively inhibits ovarian tumor growth and metastasis. Taken together, FAK PROTAC inhibits both FAK kinase activity and its scaffold protein activity by disrupting the interaction between FAK and ASAP1 and is highly effective in inhibiting ovarian tumor growth and metastasis.

Tyrosine Phosphorylation Profiling Revealed the Signaling Network Characteristics of CAMKK2 in Gastric Adenocarcinoma

Calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) is a serine/threonine protein kinase which functions via the calcium-triggered signaling cascade with CAMK1, CAMK4, and AMPKα as the immediate downstream substrates. CAMKK2 is reported to be overexpressed in gastric cancer; however, its signaling mechanism is poorly understood. We carried out label-free quantitative tyrosine phosphoproteomics to investigate tyrosine-mediated molecular signaling associated with CAMKK2 in gastric cancer cells. Using a high-resolution Orbitrap Fusion Tribrid Fourier-transform mass spectrometer, we identified 350 phosphotyrosine sites mapping to 157 proteins. We observed significant alterations in 81 phosphopeptides corresponding to 63 proteins upon inhibition of CAMKK2, among which 16 peptides were hyperphosphorylated corresponding to 13 proteins and 65 peptides were hypophosphorylated corresponding to 51 proteins. We report here that the inhibition of CAMKK2 leads to changes in the phosphorylation of several tyrosine kinases such as PKP2, PTK2, EPHA1, EPHA2, PRKCD, MAPK12, among others. Pathway analyses revealed that proteins are differentially phosphorylated in response to CAMKK2 inhibition involved in focal adhesions, actin cytoskeleton, axon guidance, and signaling by VEGF. The western blot analysis upon inhibition and/or silencing of CAMKK2 revealed a decrease in phosphorylation of PTK2 at Y925, c-JUN at S73, and STAT3 at Y705, which was in concordance with the mass spectrometry data. The study indicates that inhibition of CAMKK2 has an anti-oncogenic effect in gastric cells regulating phosphorylation of STAT3 through PTK2/c-JUN in gastric cancer.

Loss of ASAP1 in the MMTV-PyMT model of luminal breast cancer activates AKT, accelerates tumorigenesis, and promotes metastasis

ASAP1 is a multi-domain adaptor protein that regulates cytoskeletal dynamics, receptor recycling and intracellular vesicle trafficking. Its expression is associated with poor prognosis in a variety of cancers, and can promote cell migration, invasion and metastasis. Although amplification and expression of ASAP1 has been associated with poor survival in breast cancer, we found that in the autochthonous MMTV-PyMT model of luminal breast cancer, ablation of ASAP1 resulted in an earlier onset of tumor initiation and increased metastasis. This was due to tumor cell-intrinsic effects of ASAP1 deletion, as ASAP1 deficiency in tumor, but not in stromal cells was sufficient to replicate the enhanced tumorigenicity and metastasis observed in the ASAP1-null MMTV-PyMT mice. Loss of ASAP1 in MMTV-PyMT mice had no effect on proliferation, apoptosis, angiogenesis or immune cell infiltration, but enhanced mammary gland hyperplasia and tumor cell invasion, indicating that ASAP1 can accelerate tumor initiation and promote dissemination. Mechanistically, these effects were associated with a potent activation of AKT. Importantly, lower ASAP1 levels correlated with poor prognosis and enhanced AKT activation in human ER+/luminal breast tumors, validating our findings in the MMTV-PyMT mouse model for this subtype of breast cancer. Taken together, our findings reveal that ASAP1 can have distinct functions in different tumor types and demonstrate a tumor suppressive activity for ASAP1 in luminal breast cancer.

Focal adhesion kinase inhibitors in the treatment of solid tumors: Preclinical and clinical evidence

Focal Adhesion Kinase (FAK) is a 125-kDa cytoplasmic protein kinase that is implicated in several cellular functions. This protein is an attractive molecular target for cancer therapy because a wide variety of studies have demonstrated associations between the activation or elevated expression of FAK and tumor progression, invasion, and drug resistance in malignant tumors. Here, we review the strategies used to inhibit FAK activity in solid tumors. We also include an overview of the preclinical (in vitro and in vivo) and clinical studies on FAK inhibitors.

A Luminacin D Analog HL142 Inhibits Ovarian Tumor Growth and Metastasis by Reversing EMT and Attenuating the TGFβ and FAK Pathways

Epithelial to mesenchymal transition (EMT) is known to contribute to tumor metastasis and chemoresistance. Reversing EMT using small molecule inhibitors to target EMT associated gene expression represents an effective strategy for cancer treatment. The purpose of this study is to test whether a new luminacin D analog HL142 reverses EMT in ovarian cancer (OC) and has the therapeutic potential for OC. We chemically synthesized HL142 and tested its functions in OC cells in vitro and its efficacy in inhibiting ovarian tumor growth and metastasis in vivo using orthotopic OC mouse models. We first demonstrate that ASAP1 is co-amplified and interacts with the focal adhesion kinase (FAK) protein in serous ovarian carcinoma. HL142 inhibits ASAP1 and its interaction protein FAK in highly invasive OVCAR8 and moderately invasive OVCAR3 cells. HL142 inhibits EMT phenotypic switch, accompanied by upregulating epithelial marker E-cadherin and cytokeratin-7 and downregulating mesenchymal markers vimentin, β-catenin, and snail2 in both cell lines. Functionally, HL142 inhibits proliferation, colony formation, migration, and invasion. HL142 also sensitizes cell responses to chemotherapy drug paclitaxel treatment and inhibits ovarian tumor growth and metastasis in orthotopic OC mouse models. We further show that HL142 attenuates the TGFβ and FAK pathways in vitro using OC cells and in vivo using orthotopic mouse models.

Baicalein Inhibits Gastric Cancer Cell Proliferation and Migration through a FAK Interaction via AKT/mTOR Signaling

Gastric cancer is a common malignancy worldwide and is associated with high morbidity and mortality rates. However, very little is known about the underlying mechanism in human gastric cancer cells. Baicalein (BAI), a widely used Chinese herbal medicine, has shown anticancer effects on many types of human cancer cell lines. Here, we investigated the molecular mechanisms underlying BAI action on gastric cancer cell proliferation and migration. The results showed that BAI can expressively inhibit cell proliferation, colony-forming ability and migration ability in a dose-dependent manner, while in the meantime inducing cell apoptosis. Additionally, we found that BAI can suppress FAK and the phosphorylation of PI3K, AKT and mTOR in a dose-dependent manner. Furthermore, BAI significantly inhibited tumor growth in a xenograft model. Also, BAI can inhibit the proliferation and migration of gastric cancer cells and the expression of the pathway by downregulating the expression of FAK. In short, we demonstrated that BAI inhibited gastric cancer cell proliferation and migration through FAK interaction via downregulation in AKT/mTOR signaling, which signifies that BAI may be a latent therapeutic factor for the treatment of gastric cancer patients and that FAK might be a hopeful therapy target for the disease.

ADP ribosylation factor guanylate kinase 1 promotes the malignant phenotype of gastric cancer by regulating focal adhesion kinase activation

AIMS

ADP ribosylation factor guanylate kinase 1 (ASAP1), a phospholipid-dependent guanosine triphosphate (GTP)ase activating protein, has been reported to be involved in the development of various malignant tumors. However, the biological function of ASAP1 in gastric cancer (GC) remains unclear. This study was to investigate its effect and the underlying mechanism for the malignant phenotype of GC.

MATERIALS AND METHODS

The Cell Counting Kit-8 assay, flow cytometry, Transwell invasion assay, and wound-healing assay were used to assess the malignant biological behavior of GC cells with ASAP1 overexpression and knockdown. In addition, co-immunoprecipitation was used to analyze the interaction between ASAP1 and FAK in BGC823 cells, and western blotting was used to determine the effects of overexpression and knockdown of ASAP1 on FAK activity in BGC823 cells. Subsequently, functional recovery experiments were used to observe the effect of ASAP1 and FAK on the malignant phenotype of GC cells.

KEY FINDINGS

ASAP1 overexpression strongly promoted the malignant biological behavior of SGC7901 cells. Knockdown of ASAP1 effectively weakened the malignant biological behavior of SGC7901 and BGC823 cells. ASAP1 directly interacted with FAK to potentiate FAK activation. In addition, knockdown of FAK combined with ASAP1 overexpression significantly weakened the malignant biological behavior of GC cells, whereas overexpression of FAK combined with knockdown of ASAP1 significantly enhanced the malignant biological behavior of GC cells.

SIGNIFICANCE

ASAP1 interacted with FAK, and ASAP1 promoted the malignant phenotype of GC cells by regulating FAK activity. The specific underlying mechanism is worth further investigation.