Qi-Sheng Hong

Single-walled carbon nanotubes can induce pulmonary injury in mouse model.

Carbon nanotubes are a nanomaterial that is extensively used in industry. The potential health risk of chronic carbon nanotubes exposure has been raised as of great public concern. In the present study, we have demonstrated that intratracheal instillation of 0.5 mg of single-walled carbon nanotubes (SWCNT) into male ICR mice (8 weeks old) induced alveolar macrophage activation, various chronic inflammatory responses, and severe pulmonary granuloma formation. We then used Affymetrix microarrays to investigate the molecular effects on the macrophages when exposed to SWCNT. A biological pathway analysis, a literature survey, and experimental validation suggest that the uptake of SWCNT into the macrophages is able to activate various transcription factors such as nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1), and this leads to oxidative stress, the release of proinflammatory cytokines, the recruitment of leukocytes, the induction of protective and antiapoptotic gene expression, and the activation of T cells. The resulting innate and adaptive immune responses may explain the chronic pulmonary inflammation and granuloma formation in vivo caused by SWCNT.

Curcumin Suppresses Metastasis via Sp-1, FAK Inhibition, and E-Cadherin Upregulation in Colorectal Cancer

Colorectal cancer (CRC) is a serious public health problem that results due to changes of diet and various environmental stress factors in the world. Curcumin is a traditional medicine used for treatment of a wide variety of tumors. However, antimetastasis mechanism of curcumin on CRC has not yet been completely investigated. Here, we explored the underlying molecular mechanisms of curcumin on metastasis of CRC cells in vitro and in vivo. Curcumin significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. We found that curcumin suppresses Sp-1 transcriptional activity and Sp-1 regulated genes including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in CRC cells. Curcumin inhibits focal adhesion kinase (FAK) phosphorylation and enhances the expressions of several extracellular matrix components which play a critical role in invasion and metastasis. Curcumin reduces CD24 expression in a dose-dependent manner in CRC cells. Moreover, E-cadherin expression is upregulated by curcumin and serves as an inhibitor of EMT. These results suggest that curcumin executes its antimetastasis function through downregulation of Sp-1, FAK, and CD24 and by promoting E-cadherin expression in CRC cells.

Shisa3 Is Associated with Prolonged Survival through Promoting β-Catenin Degradation in Lung Cancer

RATIONALE Despite advances in treatment and prognosis of non-small cell lung cancer (NSCLC), patient outcomes are still unsatisfactory. OBJECTIVES To reduce the morbidity and mortality of patients with NSCLC, a more comprehensive understanding of mechanisms involved in cancer progression is urgently needed. METHODS By comparison of gene expression profiles in the cell line pair with differential invasion ability, CL1-0 and CL1-5, we found that Shisa3 was highly expressed in the low invasive cells. The effect of Shisa3 on invasion, migration, proliferation, apoptosis, epithelial-mesenchymal transition, and anchorage-independent growth activities in vitro and on tumor growth and metastasis in mice models were examined. The underlying mechanism of Shisa3 was explored by microarray and pathway analysis. Finally, the correlation of Shisa3 expression and clinical outcome was also calculated. MEASUREMENTS AND MAIN RESULTS We identified Shisa3 as a novel tumor suppressor, which induces β-catenin degradation resulting in suppression of tumorigenesis and invasion in vitro. Shisa3 decreased the tumor growth in mice with subcutaneous implantation and reduced the number of metastatic nodules in mice with tail vein injection and orthotopic implantation. Shisa3 performs the tumor suppression activity through WNT signaling predicted by microarray analysis. Our data found that Shisa3 accelerates β-catenin degradation and was positively associated with overall survival and progression-free survival of NSCLC. CONCLUSIONS Our results reveal that Shisa3 acts as a tumor suppressor by acceleration of β-catenin degradation and provide new insight for cancer prognosis and therapy.

Focal Amplification of HOXD-Harboring Chromosome Region Is Implicated in Multiple-Walled Carbon Nanotubes-Induced Carcinogenicity

Multiple-walled carbon nanotubes (MWCNTs) may cause carcinogenesis. We found that long-term exposure to MWCNTs can induce irreversible oncogenic transformation of human bronchial epithelial cells and tumorigenicity in vivo. A genome-wide array-comparative genomic hybridization (aCGH) analysis revealed global chromosomal aberration in MWCNTs-treated clones, predominantly at chromosome 2q31-32, where the potential oncogenes HOXD9 and HOXD13 are located. Functional assays confirmed that this variation can modulate oncogenic signaling and plays a part in MWCNTs-induced tumorigenesis, suggesting that MWCNTs are carcinogens that act by altering genomic stability and oncogenic copy numbers.

PARVA Promotes Metastasis by Modulating ILK Signalling Pathway in Lung Adenocarcinoma

α-parvin (PARVA) is known to be involved in the linkage of integrins, regulation of actin cytoskeleton dynamics and cell survival. However, the role that PARVA plays in cancer progression remains unclear. Here, using a lung cancer invasion cell line model and expression microarrays, we identify PARVA as a potential oncogene. The overexpression of PARVA increased cell invasion, colony-forming ability and endothelial cell tube formation. By contrast, knockdown of PARVA inhibited invasion and tube formation in vitro. Overexpression of PARVA also promoted tumorigenicity, angiogenesis and metastasis in in vivo mouse models. To explore the underlying mechanism, we compared the expression microarray profiles of PARVA-overexpressing cells with those of control cells to identify the PARVA-regulated signalling pathways. Pathway analysis showed that eight of the top 10 pathways are involved in invasion, angiogenesis and cell death. Next, to identify the direct downstream signalling pathway of PARVA, 371 significantly PARVA-altered genes were analysed further using a transcription factor target model. Seven of the top 10 PARVA-altered transcription factors shared a common upstream mediator, ILK. Lastly, we found that PARVA forms a complex with SGK1 and ILK to enhance the phosphorylation of ILK, which led to the phosphorylation of Akt and GSK3β. Notably, the inactivation of ILK reversed PARVA-induced invasion. Taken together, our findings imply that PARVA acts as an oncogene by activating ILK, and that this activation is followed by the activation of Akt and inhibition of GSK3β. To our knowledge, this is the first study to characterize the role of PARVA in lung cancer progression.

SPANXA suppresses EMT by inhibiting c-JUN/SNAI2 signaling in lung adenocarcinoma

SPANXA (Sperm Protein Associated with the Nucleus on the X-chromosome, family members A1/A2) acts as a cancer-testis antigen expressed in normal testes, but dysregulated in various tumors. We found that SPANXA is highly expressed in low-invasive CL1-0 cells compared with isogenous high-invasive CL1-5 cells. SPANXA was preferably expressed in tumor tissues and associated with the prolonged survival of lung adenocarcinomas. SPANXA suppressed the invasion and metastasis of lung cancer cells in vitro and in vivo. By the expression microarray and pathway analysis, we found that the SPANXA-altered genes were enriched in the epithelial–mesenchymal transition (EMT) pathway. SPANXA reduced SNAI2 expression resulted in up-regulating E-cadherin. c-JUN acts as the positive-regulator of EMT. Silencing SPANXA increased c-JUN mRNA expression and blockage of c-JUN led to SNAI2 down-regulation. Our results clearly characterized SPANXA as an EMT inhibitor by suppressing c-JUN-SNAI2 axis in lung adenocarcinoma.

HLJ1 is an endogenous Src inhibitor suppressing cancer progression through dual mechanisms

HLJ1 (DNAJB4), a DNAJ/Hsp40 chaperone, has emerged as a novel prognostic marker in lung cancers; however, the molecular contribution and functionality in neoplastic diseases remain to be established. This study demonstrated that HLJ1 inhibits epithelial–mesenchymal transition in vitro and reduces lung cancer metastasis in vivo. Using shRNA silencing and ectopic expression of HLJ1, we found that HLJ1 not only suppresses catalytic activity of Src but also downregulates the formation of oncogenic complexes associated with the EGFR, FAK and STAT3 signaling pathways. A screen of specimens from HLJ1-knockout mice and lung cancer patients validated that HLJ1 expression is inversely correlated with Src activity. Mechanistically, HLJ1 protein directly bound to catalytic and protein-binding domains of Src through its amino acid Y172 and the P301/P304 motif. Following Src-induced HLJ1 phosphorylation at Y172, HLJ1–Src interaction was elevated, resulting in Src inhibition and malignancy suppression. Interestingly, both Src-binding regions also occurred in other DNAJB family members and contributed to anti-invasive activities of DNAJB proteins. We conclude that HLJ1 is an endogenous Src inhibitor that can suppress cancer metastasis through complex interacting mechanisms. This HLJ1–Src complex might provide a promising molecular model for developing new anticancer strategies.

Abstract 3527: YYEI motif is critical to oncogenicity of 14-3-3 proteins

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA 14-3-3 family consists of seven highly conserved isoforms and most of them are identified as oncogenes in various types of cancer except for 14-3-3σ, a well-known tumor suppressor. To clarify the suppressor characteristic of 14-3-3σ divergent from others, we found that the major difference between the other oncogenic members and 14-3-3σ by protein alignment was an amino acid substitution (Y180H) by which the SH2-binding motif (YYEI) is disrupted and cannot be phosphorylation. Thus, we generated a H180Y 14-3-3σ mutant and investigated the impact of the acquired YYEI motif on the tumor suppression. First, we found that 14-3-3σ decreased cancer invasion. Surprisingly, the H180Y mutant not only enhanced cell invasion but increased cell viability. Meanwhile, the interaction between H180Y mutant and Src was higher than wild type. It indicates one amino acid substitution switches 14-3-3σ from tumor suppressor to oncogene. Hence, the YYEI motif might be important for the oncogenicity of other 14-3-3 proteins. Indeed, we demonstrated that 14-3-3ζ interacted with Src through Y178 phosphorylation, which is crucial for the binding of 14-3-3ζ with Src-SH2 domain. Owing to the importance of Y178 phosphorylation in the 14-3-3ζ/Src interaction, we introduced the Y178F 14-3-3ζ mutant to lung cancer cells and confirmed that Y178 phosphorylation is important for the increase of invasion and viability. Furthermore, we also revealed an amino acid switch of 14-3-3σ from YYEI to HYEI during evolutionary progression. Taken together, our findings suggest that YYEI motif is essential for 14-3-3 proteins to interact with Src and to regulate Src-mediated cell functions. Citation Format: Wen-Hsin Chang, Ching-Hsien Chen, Qi-Sheng Hong, Jian-Wei Chen, Sung-Liang Yu, Chiung-Tong Chen. YYEI motif is critical to oncogenicity of 14-3-3 proteins. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3527. doi:10.1158/1538-7445.AM2014-3527