lithium-chloride and Esophageal-Neoplasms

Although GSK3β has been reported to have contrasting effects on the progression of different tumors, it's possible functions in esophageal squamous cell carcinoma (ESCC) and the related molecular mechanisms remain unknown. Here, we investigated the expression, function, and molecular mechanism of GSK3β in the development of ESCC in vitro and in vivo. Though the expression of total GSK3β was significantly increased, the phosphorylated (inactivated) form of GSK3β (Ser9) was concurrently decreased in the cancerous tissues of patients with ESCC compared with controls, suggesting that GSK3β activity was enhanced in cancerous tissues. Further pathological data analysis revealed that higher GSK3β expression was associated with poorer differentiation, higher metastasis rates, and worse prognosis of ESCC. These results were confirmed in different ESCC cell lines using a pharmacological inhibitor and specific siRNA to block GSK3β. Using a cancer phospho-antibody array, we found that STAT3 is a target of GSK3β. GSK3 inhibition reduced STAT3 phosphorylation, and overexpression of constitutively active GSK3β had the opposite effect. Moreover, STAT3 inhibition mimicked the effects of GSK3β inhibition on ESCC cell migration and viability, while overexpression of a plasmid encoding mutant STAT3 (Y705F) abrogated these effects, and these results were further substantiated by clinicopathological data. In addition, a GSK3 inhibitor (LiCl) and/or STAT3 inhibitor (WP-1066) efficiently suppressed the growth of ESCC cells in a xenograft tumor model. Altogether, these results reveal that higher GSK3β expression promotes ESCC progression through STAT3 in vitro and in vivo, and GSK3β-STAT3 signaling could be a potential therapeutic target for ESCC treatment.

Topics: Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Survival; Disease Progression; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Female; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Male; Mice; Phosphorylation; Prognosis; Pyridines; Signal Transduction; STAT3 Transcription Factor; Survival Analysis; Tyrphostins; Up-Regulation

Many epithelial cancers, particularly gastrointestinal tract cancers, remain poor prognosis diseases, due to resistance to cytotoxic therapy and local or metastatic recurrence. We have previously shown that apoptosis incompetent esophageal cancer cells induce autophagy in response to chemotherapeutic agents and this can facilitate their recovery. However, known pharmacological inhibitors of autophagy could not enhance cytotoxicity. In this study, we have examined two well known, clinically approved autophagy inducers, rapamycin and lithium, for their effects on chemosensitivity in apoptosis incompetent cancer cells. Both lithium and rapamycin were shown to induce autophagosomes in esophageal and colorectal cancer cells by western blot analysis of LC3 isoforms, morphology and FACS quantitation of Cyto-ID or mCherry-GFP-LC3. Analysis of autophagic flux indicates inefficient autophagosome processing in lithium treated cells, whereas rapamycin treated cells showed efficient flux. Viability and recovery was assessed by clonogenic assays. When combined with the chemotherapeutic agent 5-fluorouracil, rapamycin was protective. In contrast, lithium showed strong enhancement of non-apoptotic cell death. The combination of lithium with 5-fluorouracil or oxaliplatin was then tested in the syngenic mouse (balb/c) colorectal cancer model--CT26. When either chemotherapeutic agent was combined with lithium a significant reduction in tumor volume was achieved. In addition, survival was dramatically increased in the combination group (p < 0.0001), with > 50% of animals achieving long term cure without re-occurrence (> 1 year tumor free). Thus, combination treatment with lithium can substantially improve the efficacy of chemotherapeutic agents in apoptosis deficient cancer cells. Induction of compromised autophagy may contribute to this cytotoxicity.

Topics: Animals; Antineoplastic Agents; Autophagy; Cell Line, Tumor; Colorectal Neoplasms; Drug Synergism; Esophageal Neoplasms; Female; Fluorouracil; Genes, Reporter; Humans; Lithium Chloride; Mice; Mice, Inbred BALB C; Microscopy, Confocal; Organoplatinum Compounds; Oxaliplatin; Sirolimus; Transplantation, Heterologous

To investigate the effect of lithium on proliferation of esophageal cancer (EC) cells and its preliminary mechanisms.. Eca-109 cells were treated with lithium chloride, a highly selective inhibitor of glycogen synthase kinase 3beta (GSK-3beta), at different concentrations (2-30 mmol/L) and time points (0, 2, 4, 6 and 24 h). Cell proliferative ability was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, and cell cycle distribution was examined by flow cytometry. Expressions of p-GSK-3beta, beta-catenin, cyclin B1, cdc2 and cyclin D1 protein were detected by Western blotting, and the subcellular localization of beta-catenin was determined by immunofluorescence. The mRNA level of cyclin B1 was detected by reverse transcription polymerase chain reaction (RT-PCR).. Lithium could inhibit the proliferation of Eca-109 cells. Lithium at a concentration of 20 mmol/L lithium for 24 h produced obvious changes in the distribution of cell cycle, and increased the number of cells in G(2)/M phase (P<0.05 vs control group). Western blotting showed that lithium inhibited GSK-3beta by Ser-9 phosphorylation and stabilized free beta-catenin in the cytoplasm. Immunofluorescence further confirmed that free beta-catenin actively translocated to the nucleus. Moreover, lithium slightly elevated cyclin D1 protein expression, whereas lowered the cyclin B1 expression after 24 h lithium exposure and no obvious change was observed for cdc2 protein.. Lithium can inhibit the proliferation of human esophageal cancer cell line Eca-109 by inducing a G(2)/M cell cycle arrest, which is mainly mediated through the inhibition of lithium-sensitive molecule, GSK-3beta, and reduction of cyclin B1 expression.

Topics: Active Transport, Cell Nucleus; Antineoplastic Agents; beta Catenin; Cell Division; Cell Line, Tumor; Cell Proliferation; Cyclin B; Cyclin B1; Cyclin D; Cyclins; Dose-Response Relationship, Drug; Enzyme Inhibitors; Esophageal Neoplasms; G2 Phase; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Phosphorylation; RNA, Messenger; Time Factors

The immunomodulatory effect of lithium chloride was studied. The IL-2 and IFNr production by peripheral blood mononuclear cells(PBMC) were assayed in 52 normal subjects and 156 cancer patients. IL-2 and IFN-r levels in lymphoma patients were lower than in normal subjects. The IFNr level in the majority of patients with lung and esophageal cancers was abnormal but the IL-2 level was within the normal range. When lithium, IL-2 was incubated with PBMC in vitro, upregulation of IL-2 and IFNr production was observed in normal subjects and cancer patients. The IL-2 and IFNr levels were significantly increased by both lithium and rIL-2 but the effect of lithium was more potent. Lithium upregulated IFNr in 70% of patients with low levels whereas it did so in only 10-20% of patients with high levels. Therefore, lithium is a promising new immunoregulatory agent for clinical use.

Topics: Chlorides; Esophageal Neoplasms; Humans; Interferon-gamma; Interleukin-2; Leukocytes, Mononuclear; Lithium; Lithium Chloride; Lung Neoplasms; Lymphoma