Screening of early-staged colorectal neoplasia by clonal hematopoiesis-based liquid biopsy and machine-learning.

Liquid biopsy test has a better uptake for colorectal cancer (CRC) screening. However, suboptimal detection of early-staged colorectal neoplasia (CRN) limits its application. Here, we established an early-staged CRN blood test using error-corrected sequencing by comparing clonal hematopoiesis (CH) of 63 CRN patients and that of 32 controls. We identified 1,446 variants and classified the uniqueness in CRN patients. There was no significance difference in the amount of variant between CRNs and controls, but the uniqueness of variants with defective DNA mismatch repair-related mutational signature was addressed from peripheral blood in early-staged CRN patients. By machine learning approach, the early-staged CRNs was discriminated from controls with an AUC of 0.959 and an accuracy of 0.937 (95% CI, 0.863 to 0.968). The CRN predictive model was further validated by additional 20 CRNs and 10 controls and showed the accuracy, sensitivity, specificity, positive prediction value (PPV) and negative prediction value (NPV) of 0.933 (95% CI: 0.779 to 0.992), 0.95, 0.90, 0.95 and 0.90, respectively. In summary, we develop a CH-based liquid biopsy test with machine learning approach, which not only increase screening uptake but also improve the detection rate of early-staged CRN.

Mitochondrial apoptosis and FAK signaling disruption by a novel histone deacetylase inhibitor, HTPB, in antitumor and antimetastatic mouse models.

BACKGROUND: Compound targeting histone deacetylase (HDAC) represents a new era in molecular cancer therapeutics. However, effective HDAC inhibitors for the treatment of solid tumors remain to be developed. METHODOLOGY/PRINCIPAL FINDINGS: Here, we propose a novel HDAC inhibitor, N-Hydroxy-4-(4-phenylbutyryl-amino) benzamide (HTPB), as a potential chemotherapeutic drug for solid tumors. The HDAC inhibition of HTPB was confirmed using HDAC activity assay. The antiproliferative and anti-migratory mechanisms of HTPB were investigated by cell proliferation, flow cytometry, DNA ladder, caspase activity, Rho activity, F-actin polymerization, and gelatin-zymography for matrix metalloproteinases (MMPs). Mice with tumor xenograft and experimental metastasis model were used to evaluate effects on tumor growth and metastasis. Our results indicated that HTPB was a pan-HDAC inhibitor in suppressing cell viability specifically of lung cancer cells but not of the normal lung cells. Upon HTPB treatment, cell cycle arrest was induced and subsequently led to mitochondria-mediated apoptosis. HTPB disrupted F-actin dynamics via downregulating RhoA activity. Moreover, HTPB inhibited activity of MMP2 and MMP9, reduced integrin-ß1/focal adhesion complex formation and decreased pericellular poly-fibronectin assemblies. Finally, intraperitoneal injection or oral administration of HTPB efficiently inhibited A549 xenograft tumor growth in vivo without side effects. HTPB delayed lung metastasis of 4T1 mouse breast cancer cells. Acetylation of histone and non-histone proteins, induction of apoptotic-related proteins and de-phosphorylation of focal adhesion kinase were confirmed in treated mice. CONCLUSIONS/SIGNIFICANCE: These results suggested that intrinsic apoptotic pathway may involve in anti-tumor growth effects of HTPB in lung cancer cells. HTPB significantly suppresses tumor metastasis partly through inhibition of integrin-ß1/FAK/MMP/RhoA/F-actin pathways. We have provided convincing preclinical evidence that HTPB is a potent HDAC targeted inhibitor and is thus a promising candidate for lung cancer chemotherapy.

The novel indole compound SK228 induces apoptosis and FAK/Paxillin disruption in tumor cell lines and inhibits growth of tumor graft in the nude mouse.

Drugs in clinical use with indole structure exhibit side effects. Therefore, to search for indole compounds with more efficacy and less side effect for cancer therapy, we developed a novel indole compound SK228 and examined its effects and mechanisms on antitumor growth and invasion inhibition in cell and tumor xenografts in nude mice models. SK228 significantly inhibited growth of different lung and esophageal cancer cell lines at sub-micromolar range, but not normal lung cells. SK228 induced DNA damages mainly by producing reactive oxygen species (ROS) resulting in apoptosis. SK228 treatment increased the release of cytochrome c into the cytosol along with the increased activity of caspase-3 and -9 without affecting caspase-8, whereas these effects were attenuated by ROS inhibitor. The expression levels of BCL-2 family regulators were also affected. Moreover, low-dose SK228 significantly reduced the invasion of cancer cells. The active phosphorylated form of FAK/Paxillin signaling pathway proteins and active form of RhoA were decreased. Moreover, the F-actin cytoskeleton was disrupted after low-dose SK228 treatment. Growth of an A549 tumor cell xenograft was markedly inhibited without significant side effects. SK228-induced apoptosis was confirmed by terminal deoxynucleotidyl transferase dUTP nick end labeling assay and immunohistochemistry of cleaved caspase-3 in tumors from treated mice. Our study provides the first evidence that SK228 exhibits cancer cell-specific cytotoxicity by inducing mitochondria-mediated apoptosis. In addition, SK228 inhibits cancer cell invasion via FAK/Paxillin disruption at noncytotoxic doses. SK228 can be further tested as a pharmaceutical compound for cancer treatment.

ATM/ATR and SMAD3 pathways contribute to 3-indole-induced G1 arrest in cancer cells and xenograft models.

BACKGROUND: 3-Indole inhibits lung cancer growth by apoptosis. Here, the growth inhibition mechanism besides apoptosis was further characterized. MATERIALS AND METHODS: The Comet assay was used to examine 3-indole-induced DNA damage. Cell cycle distribution and protein expression were analyzed using flow cytometry, Western blotting and immunohistochemistry in cell and animal models. RESULTS: 3-Indole induced dose-dependent DNA damage, which was reversed by reactive oxygen species (ROS) inhibitor in lung cancer cells. Cell cycle G1 arrest was observed in the 3-indole-treated cells. DNA damage-responsive proteins involved in the ataxia telangiectasia mutated/ataxia telangiectasia and Rad3-related (ATM/ATR) pathway and G1 regulation proteins such as p21 and SMA- and MAD-related protein 3 (SMAD3) were induced in the cell models. The altered expression of ATM, ATR, checkpoint kinase 2 (CHK2), and cell division cycle 25 homolog A (CDC25A) were confirmed in xenograft models. Importantly, the 3-indole-induced ATM/ATR and transforming growth factor (TGF)-ß/SMAD pathways were attenuated by ROS inhibitor. CONCLUSION: 3-Indole causes DNA damage and triggers ATM/ATR and SMAD3 signaling pathways to arrest lung cancer cells at the G1-phase.

A novel sialyltransferase inhibitor suppresses FAK/paxillin signaling and cancer angiogenesis and metastasis pathways.

Increased sialyltransferase (ST) activity promotes cancer cell metastasis, and overexpression of cell surface sialic acid correlates with poor prognosis in cancer patients. To seek therapies targeting metastasis for cancer treatment, we developed a novel ST inhibitor, Lith-O-Asp, and investigated its antimetastatic and antiangiogenic effects and mechanisms. We found that cells treated with Lith-O-Asp showed a reduction of activity on various ST enzymes by in vitro and cell-based activity analyses. Lith-O-Asp inhibited migration and invasion abilities in various cancer cell lines and showed inhibitory effect on the angiogenic activity of human umbilical vein endothelial cells. Indeed, Lith-O-Asp treatment consequently delayed cancer cell metastasis in experimental and spontaneous metastasis assays in animal models. Importantly, Lith-O-Asp decreased the sialic acid modification of integrin-ß1 and inhibited the expression of phospho-FAK, phospho-paxillin, and the matrix metalloprotease (MMP) 2 and MMP9. Lith-O-Asp attenuated the Rho GTPase activity leading to actin dynamic impairment. In addition, 2DE-MS/MS and immunoblotting analyses showed that Lith-O-Asp altered the protein expression level and phosphorylation status of various proteins involved in crucial metastasis and angiogenesis pathways such as vimentin and ribonuclease/angiogenin inhibitor RNH1. Furthermore, Lith-O-Asp treatment significantly inhibited the invasive ability exerted by ectopic overexpression of various ST enzymes catalyzing α-2,6- or α-2,3-sialylation. Our results provide compelling evidence that the potential pan-ST inhibitor, Lith-O-Asp, suppressed cancer cell metastasis likely by inhibiting FAK/paxillin signaling and expressing antiangiogenesis factors. Lith-O-Asp is worthy for further testing as a novel antimetastasis drug for cancer treatment.

Novel 2-step synthetic indole compound 1,1,3-tri(3-indolyl)cyclohexane inhibits cancer cell growth in lung cancer cells and xenograft models.

BACKGROUND: The clinical responses to chemotherapy in lung cancer patients are unsatisfactory. Thus, the development of more effective anticancer drugs for lung cancer is urgently needed. METHODS: A 2-step novel synthetic compound, referred to as 1,1,3-tri(3-indolyl)cyclohexane (3-indole), was generated in high purity and yield. 3-Indole was tested for its biologic activity in A549, H1299, H1435, CL1-1, and H1437 lung cancer cells. Animal studies were also performed. RESULTS: The data indicate that 3-indole induced apoptosis in various lung cancer cells. Increased cytochrome-c release from mitochondria to cytosol, decreased expression of antiapoptotic Bcl-2, and increased expression of proapoptotic Bax were observed. In addition, 3-indole stimulated caspases-3, -9, and to a lesser extent caspase-8 activities in cancer cells, suggesting that the intrinsic mitochondria pathway was the potential mechanism involved in 3-indole-induced apoptosis. 3-Indole-induced a concentration-dependent mitochondrial membrane potential dissipation and an increase in reactive oxygen species (ROS) production. Activation of c-Jun N-terminal kinase (JNK) and triggering of DNA damage were also apparent. Note that 3-indole-induced JNK activation and DNA damage can be partially suppressed by an ROS inhibitor. Apoptosis induced by 3-indole could be abrogated by ROS or JNK inhibitors, suggesting the importance of ROS and JNK stress-related pathways in 3-indole-induced apoptosis. Moreover, 3-indole showed in vivo antitumor activities against human xenografts in murine models. CONCLUSIONS: On the basis of its potent anticancer activity in cell and animal models, the data suggest that this 2-step synthetic 3-indole compound of high purity and yield is a potential candidate to be tested as a lead pharmaceutical compound for cancer treatment.