Role of TIM-1 in the development and treatment of tumours.

T-cell immunoglobulin and mucin structural domain 1 (TIM-1, also known as hepatitis A virus cell receptor 1) is a co-stimulatory molecule that is expressed predominantly on the surface of T cells. TIM-1 promotes the activation and proliferation of T cells, cytokine secretion, and can also be overexpressed in various types of cancer. Upregulation of TIM-1 expression may be associated with the development and progression of cancer. After reviewing the literature, we propose that TIM-1 affects tumour development mainly through two pathways. In the Direct pathway: overexpression in tumours activates tumour-related signaling pathways, mediates the proliferation, apoptosis, invasion and metastasis, and directly affects tumour development directly. In the indirect pathway: In addition to changing the tumour microenvironment and influencing the growth of tumours, TIM-1 binds to ligands to encourage the activation, proliferation, and generation of cytokines by immune cells. This review examines how TIM-1 stimulates the development of tumours in direct and indirect ways, and how TIM-1 is exploited as a target for cancer therapy.

TIM-1 promotes proliferation and metastasis, and inhibits apoptosis, in cervical cancer through the PI3K/AKT/p53 pathway.

BACKGROUND: T-cell immunoglobulin mucin-1 (TIM-1) has been reported to be associated with the biological behavior of several malignant tumors; however, it is not clear whether it has a role in cervical cancer (CC). METHODS: TIM-1 expression in cervical epithelial tumor tissues and cells was detected by immunohistochemistry or real-time quantitative-PCR and western blotting. CC cells from cell lines expressing low levels of TIM-1 were infected with lentiviral vectors encoding TIM-1. Changes in the malignant behavior of CC cells were assessed by CCK-8, wound healing, Transwell migration and invasion assays, and flow cytometry in vitro; while a xenograft tumor model was established to analyze the effects of TIM-1 on tumor growth in vivo. Changes in the levels of proteins related to the cell cycle, apoptosis, and Epithelial-mesenchymal transition (EMT) were determined by western blotting. RESULTS: TIM-1 expression was higher in CC tissues, than in high grade squamous intraepithelial lesion, low grade squamous intraepithelial lesion, or normal cervical tissues, and was also expressed in three CC cell lines. In HeLa and SiHa cells overexpressing TIM-1, proliferation, invasion, and migration increased, while whereas apoptosis was inhibited. Furthermore, TIM-1 downregulated the expression of p53, BAX, and E-cadherin, and increased cyclin D1, Bcl-2, Snail1, N-cadherin, vimentin, MMP-2, and VEGF. PI3K, p-AKT, and mTOR protein levels also increased, while total AKT protein levels remained unchanged. CONCLUSIONS: Our study indicated that TIM-1 overexpression promoted cell migration and invasion, and inhibited cell apoptosis in CC through modulation of the PI3K/AKT/p53 and PI3K/AKT/mTOR signaling pathways, and may be a candidate diagnostic biomarker of this disease.

TIM-3 Participates in the Invasion and Metastasis of Nasopharyngeal Carcinoma via SMAD7/SMAD2/SNAIL1 Axis-Mediated Epithelial-Mesenchymal Transition.

BACKGROUND: T-cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) was originally found to negatively regulate immune response and mediate immune escape in tumors. Subsequently, an increasing body of evidence has shown that TIM-3 exerts positive functions in the development and progression of several tumors. However, the role of TIM-3 in nasopharyngeal carcinoma (NPC) remains unknown. METHODS: Data from the Cancer Genome Atlas-head and neck squamous cell carcinoma and immunohistochemistry were analyzed to compare the expression of TIM-3 in NPC and non-cancerous nasopharyngitis tissues. Cell proliferation was evaluated using the Cell counting kit-8 in vitro and xenograft experiment in nude mice in vivo. Flow cytometry was used to evaluate the cell cycle. The migration and invasion of NPC cells were assessed through wound healing and Transwell assays. In addition, Western blotting was used to analyze the expression of specific proteins. RESULTS: Higher expression of TIM-3 was detected in NPC tissues than normal nasopharyngeal tissues and positively correlated with the clinical stage and T classification; however, it was not correlated with gender, age, and N classification. Furthermore, overexpression of TIM-3 using lentiviral vectors increased the malignancy of 6-10B and CNE-2 cell lines that lowly express TIM-3, by promoting cell proliferation, migration, and invasion in vitro and in vivo. In addition, overexpression of TIM-3 was associated with upregulation of matrix metalloproteinase 9 (MMP9) and MMP2, and led to epithelial-mesenchymal transition (EMT) by increasing the levels of mesenchymal markers (ie, N-cadherin, Vimentin) and decreasing those of the epithelial marker E-cadherin. Further study showed that SMAD7 was downregulated in the TIM-3 overexpression group. Relatively, phosphorylated SMAD2 and downstream molecule SNAIL1 were also upregulated in this group. CONCLUSION: TIM-3 exerts a tumor-promoting function in NPC by mediating changes in the SMAD7/SMAD2/SNAIL1 axis. These findings provide a new idea for the study of invasion, metastasis, and treatment of NPC.

A novel compound heterozygosity in Southern China: IVS-II-5 (G > C) and IVS-II-672 (A > C).

ß-Thalassemia (ß-thal) is a common hereditary anemia due to decreased or absent synthesis of the ß-globin chains. Here, we report a patient found to be a novel compound heterozygote for the rare IVS-II-5 (G > C) (NG_000007.3: g.71044G > C) and IVS-II-672 (A > C) (NG_000007.3: g.71711A > C) mutations, which may be silent mutations that are associated with consistent residual output of ß chains, normal red blood cell (RBC) indices and normal or borderline Hb A2 levels.

Construction and characterization of an enhanced GFP-tagged TIM-1 fusion protein.

TIM-1 (also known as KIM-1 and HAVcr-1) is a type I transmembrane glycoprotein member of the TIM family that may play important roles in innate and adaptive immune responses. The overexpression of proteins associated with membrane proteins is a major obstacle to overcome in studies of membrane protein structures and functions. In this study, we successfully coupled the overexpression of the TIM-1 protein with a C-terminal enhanced green fluorescent protein (GFP) tag in Escherichia coli. To the best of our knowledge, this report is the first to describe the overexpression of human TIM-1 in E. coli. The purified TIM-1-EGFP fusion protein recognized and bound directly to apoptotic cells and did not to bind to viable cells. Furthermore, we confirmed that the interactions of TIM-1-EGFP with apoptotic cells were blocked by TIM-1-Fc fusion proteins. This fusion protein represents a readily obtainable source of biologically active TIM-1 that may prove useful in future studies of human TIM-1.

Construction and characterization of bifunctional TIM-3-EGFP fusion proteins.

T cell immunoglobulin mucin-3 (TIM-3) is the first surface molecule to be found that specifically identifies Th1 cells in both mice and humans, and it negatively regulates Th1 responses. TIM-3 protein is a type I membrane protein. Overexpression of membrane proteins is a major problem to overcome in studies of membrane protein structure and function. In this study, a fusion between the gene encoding human TIM-3 and EGFP was successfully constructed and expressed in Escherichia coli. To our knowledge, this is the first time that human TIM-3 has been overexpressed in E. coli. We showed that the TIM-3-EGFP fusion protein mediates the recognition and binding of apoptotic cells. Furthermore, we demonstrated that the interactions of TIM-3-EGFP with apoptotic cells were blocked by TIM-3-Ig fusion proteins. Taken together, these results suggest that the human TIM-3 protein may act as a receptor for apoptotic cells.

Interactions of human T cell immunoglobin mucins with apoptotic cells.

T cell immunoglobulin mucin (TIM) family plays a key role in regulating immune responses. In this study, the interactions of human TIM family with apoptotic cells were evaluated in order to provide a foundation for further study on the roles of human TIM genes in apoptosis. Nine kinds of pEGFP-N1 eukaryotic expression vectors containing different lengths of the three members of human TIM genes for the expression of TIM-EGFP and the vectors for the expression of TIM-Fc fusion proteins were constructed. It was found that human TIM proteins could recognize and bind to apoptotic cells directly, but not to viable cells. The interactions of sTIM-1-EGFP, sTIM-3-EGFP and sTIM-4-EGFP with apoptotic cells were blocked by TIM-1-Ig, TIM-3-Ig and TIM-4-Ig fusion proteins respectively. In addition, human TIM proteins mediated the recognition of apoptotic cells and bound to apoptotic cells directly via the IgV domains. In conclusion, the TIM family may play a key role in the regulation of apoptosis. Our data also suggest that human TIM proteins probably serve as novel proteins for the detection of the early cellular apoptosis.