Elucidating molecular mechanisms and therapeutic synergy: irreversible HER2-TKI plus T-Dxd for enhanced anti-HER2 treatment of gastric cancer.

BACKGROUND: HER2-targeted therapies have improved the outcomes of HER2-positive gastric cancer (GC), yet resistance remains a challenge. We sought to explore the effects of reversible and irreversible HER2 tyrosine kinase inhibitors (TKIs) alone or in combination with the HER2-targeting antibody drug conjugate trastuzumab deruxtecan (T-Dxd). METHODS: The effects of HER2-TKIs on HER2 and downstream signaling were evaluated via Western blotting. Proteasomal inhibitors and co-immunoprecipitation assays were performed to explore the role of proteasomal degradation in HER2 expression modulation, and immunofluorescence assays were employed to explore mechanisms of HER2 internalization. The synergistic potential of the irreversible HER2-TKI pyrotinib in combination with T-Dxd was validated using growth and viability assays in anti-HER2-positive GC cell cultures and tumor growth and immunohistochemical staining assays in a mouse xenograft model. RESULTS: Our study revealed that reversible HER2-TKIs elevated HER2 protein levels, whereas irreversible HER2-TKIs decreased them. Pyrotinib triggered HER2 degradation within the proteasome by promoting ubiquitination and dissociation from HSP90. Furthermore, pyrotinib substantially induced HER2 internalization, which led to improved cellular uptake of T-Dxd. The increased T-Dxd uptake was accompanied by greater efficacy in suppressing the growth of GC cells and enhanced anti-tumor effects in an animal model. CONCLUSION: In summary, our research reveals the molecular mechanisms of irreversible HER2-TKIs in regulating HER2 protein expression by promoting HER2 internalization. These findings advance our comprehension of targeted therapy for GC and provide a promising therapeutic combination strategy with enhanced efficacy against HER2-positive GC.

Synergistic antitumor effects of circularly permuted TRAIL with doxorubicin in triple-negative breast cancer.

Circularly permuted TRAIL (CPT), a novel recombinant TRAIL mutant, is a potent antitumor agent. However, its efficacy in triple-negative breast cancer (TNBC) remains unclear. Treatment with CPT alone and in combination with doxorubicin (Dox) is explored for its effects on the proliferation and apoptosis of MDA-MB-231 (MB231) and MDA-MB-436 (MB436) breast cancer cells in vitro and in vivo. Here, we show that CPT combined with Dox exhibits time- and dose-dependent synergy to inhibit cell viability and enhance apoptosis of MB231 and MB436 cells. Combined treatment substantially increases caspase-8, caspase-3, and PARP cleavage in both cell lines and significantly suppresses tumor growth in nude mice bearing MB231 xenografts. Collectively, our findings demonstrate that treatment with CPT in combination with Dox exerts synergistic antitumor effects through activation of the caspase cascade pathway, a mechanism that is partly dependent on the Dox-induced upregulation of death receptor 4 and death receptor 5. Therefore, CPT combined with Dox may be a feasible therapeutic strategy for the management of TNBC.

Pyrotinib shows a potent antitumor effect on HER2-positive esophageal cancer cells by promoting HER2 proteasomal degradation.

Pan-HER TKIs (pyrotinib, lapatinib) are potent HER2 inhibitors, however, their anti-tumor efficacy on esophageal cancer remains to be elucidated. Using two HER2-positive esophageal cancer cell lines, we observed that both pyrotinib and lapatinib could significantly suppress the activation of HER2 and its downstream signaling. However, pyrotinib showed a potent inhibitory effect at 0.1 µM treatment relative to 1 µM of lapatinib. Moreover, treatment with pyrotinibm, but not lapatinib, markedly reduced the protein level of HER2 through enhancing HER2 ubiquitination level and proteasomal degradation. In vitro and in vivo experiments further revealed that pyrotinib effectively suppresses cancer cell invasion and migration, as well as the growth of tumors in nude mice. Overall, our results suggest that pyrotinib is a superior TKI over lapatinib in inhibiting esophageal cancer cell proliferation and tumorigenic potential, and can be chosen as a neo-adjuvant for esophageal cancer treatment.

[Retracted] Filamin A regulates EGFR/ERK/Akt signaling and affects colorectal cancer cell growth and migration.

Following the publication of this article, an interested reader drew to the authors' attention that various panels in the scratch-wound assays shown in Fig. 1C appeared to contain overlapping sections, such that the data may have been derived from a more limited selection of original sources where the data were intended to show the data from discrete experiments. Furthermore, the results shown in the Kaplan-Meier overall survival analysis plots in Fig. 4C appeared to be inconsistent with the date of publication of this article. Independently, the Editorial Office also investigated the issues of concern in this article, and although the authors attenpted to explain these issues and requested the publication of a corrigendum, the Editor of Molecular Medicine Reports has declined this request and determined that this article should be retracted from the journal on the basis of an overall lack of confidence in the presented data. Upon receiving this decision from the Editor, the authors were not in agreement that the article should be retracted. The Editor apologizes to the readership of the Journal for any inconvenience caused. [Molecular Medicine Reports 20: 3671-3678, 2019; DOI: 10.3892/mmr.2019.10622].

Filamin A regulates EGFR/ERK/Akt signaling and affects colorectal cancer cell growth and migration.

The metastasis and recurrence rate, and the overall prognosis of colorectal cancer (CRC) remain unsatisfactory. Filamin A (FLNa), as an actin­binding protein, can interact with various signaling molecules and membrane receptors to affect cell signal transduction and function. However, whether FLNa is involved in the progression of CRC remains to be elucidated. The aim of the present study was to explore the role of FLNa in CRC cell proliferation and migration, as well as in the regulation of epidermal growth factor receptor (EGFR) signaling. Following transfection with a FLNa­targeting short hairpin RNA plasmid to knockdown expression of FLNa in the EGF­treated SW480 cell line, it was found that decreased expression of FLNa promoted cell proliferation and migration. Additionally, there was a negative correlation between FLNa levels and the activation of EGFR and Akt signaling pathways. Similarly, the expression of FLNa was significantly lower in human CRC tissues compared with adjacent normal tissues and FLNa expression was negatively correlated with the expression of Ki­67 in human CRC tissues. Although there was no significant difference in the Kaplan­Meier estimate of CRC between high expression and low expression of FLNa, there were significant negative associations between FLNa expression and TNM stage. The results suggested that FLNa may participate in EGF­induced cell proliferation and migration in CRC cells. Hence, interventions in the FLNa­mediated signaling pathway could provide attractive therapeutic targets for CRC.

Effects of Recombinant Circularly Permuted Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) (Recombinant Mutant Human TRAIL) in Combination with 5-Fluorouracil in Human Colorectal Cancer Cell Lines HCT116 and SW480.

BACKGROUND Circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, a mutant form of tumor necrosis factor-related apoptosis-inducing ligand, is an effective antitumor cytokine. However, its antitumor effect in colorectal cancer is unclear. This study assessed the antitumor effect of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or with 5-fluorouracil in colorectal cancer cells in vitro and explored the underlying mechanisms. MATERIAL AND METHODS We used the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay to analyze cell proliferation inhibition. The apoptotic effects of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, 5-fluorouracil, or both in human colorectal cancer cells were evaluated using flow cytometry. Furthermore, the levels of apoptosis-related proteins were examined by Western blotting. RESULTS Compared to either agent alone, cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed obvious antitumor effects and induced significant apoptosis of colorectal cancer cells. 5-Fluorouracil enhanced circularly permuted tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by increasing death receptor 4 and 5 levels in HCT116 cells, but only of death receptor 4 in SW480 cells. Moreover, 5-fluorouracil plus circularly permuted tumor necrosis factor-related apoptosis-inducing ligand increased apoptosis-related protein levels such as cleaved caspase-3, caspase-8, and poly-ADP-ribose polymerase and downregulated that of the survival protein B-cell lymphoma-extra-large. Pretreatment with the pan-caspase inhibitor, z-VAD-FMK, attenuated the caspase-dependent apoptosis induced by circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or combined with 5-fluorouracil. CONCLUSIONS Cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed enhanced antitumor effects on colorectal cancer cells.

Caveolin-1 Inhibits Proliferation, Migration, and Invasion of Human Colorectal Cancer Cells by Suppressing Phosphorylation of Epidermal Growth Factor Receptor.

BACKGROUND Although downregulation of caveolin-1 (Cav-1), which is a key constituent of membrane caveolae and a regulator of cellular processes, is associated with colorectal cancer (CRC), its involvement in the disease progression is largely unknown. This study aimed to explore the role of Cav-1 in CRC and the associated mechanisms. MATERIAL AND METHODS Fresh tissues from patients with CRC and human CRC SW480 cells were used to evaluate Cav-1 and Ki-67 expression using immunohistochemistry and Western blotting. The MTS and Transwell assays were performed to determine the effects of Cav-1 overexpression via pcDNA3.1/Cav-1 plasmid on cell proliferation and metastasis. The effect of Cav-1 on the epidermal growth factor receptor (EGFR) activation was evaluated by Western blotting. The correlation of Cav-1 expression with clinicopathological factors was statistically analyzed. RESULTS Overexpression of Cav-1 significantly reduced proliferation, migration, and invasion of SW480 cancer cells in vitro. The EGF-induced phosphorylation of EGFR and activations of the RAF-MEK-ERK and PI3K-AKT pathways were adversely regulated by Cav-1 overexpression in vitro. In 76 cases of CRC patients with EGFR expression, a negative correlation was observed between the level of Cav-1 and tumor-node-metastasis stage, lymph node metastasis, and distant metastasis (All p<0.05). Finally, the expression level of Cav-1 was negatively correlated with that of Ki-67. CONCLUSIONS This report is the first to show that overexpression of Cav-1significantly inhibits the proliferation, migration, and invasion potential of SW480 cells, possibly through reducing EGF-induced EGFR activation. High Cav-1 expression level may be a predictor of positive outcomes in patients with colorectal cancer.

FLNa negatively regulated proliferation and metastasis in lung adenocarcinoma A549 cells via suppression of EGFR.

Filamin A (FLNa) is a ubiquitously expressed cytoplasmic protein, which composes of an N-terminal actin binding domain (ABD) followed by 24 Ig-like repeats. FLNa functions as a cytoskeletal protein that links transmembrane receptors, including integrins, to F-actin and serves as a signaling intermediate. Recent studies have identified FLNa as a scaffold protein that interacts with over 90 proteins and plays vital roles in cellular signaling transduction. Mutations or defects in human FLNa gene have been shown to cause numerous developmental defects. Moreover, aberrant expression of FLNa has been observed in many cancers, such as parathyroid tumor, cervical cancer, and breast cancer. However, its role in lung adenocarcinoma has seldom been discussed. In the present study, our in vitro and in vivo studies demonstrated that silencing FLNa expression in lung cancer cell line A549 cells promoted proliferation, migration, and invasiveness of A549 cells by enhancing the activation of epidermal growth factor receptor and ERK signaling pathway. These results shed light on novel functions of FLNa in lung cancer and uncovered novel mechanisms, these results provided possible targets for the prediction and treatment for lung adenocarcinoma.

Downregulation of caveolin-1 increased EGFR-TKIs sensitivity in lung adenocarcinoma cell line with EGFR mutation.

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), including gefitinib and erlotinib, have shown notable effects in lung adenocarcinoma patients harboring EGFR mutations, there are significant differences between individual patients in the degree of benefits provided by EGFR-TKIs. Some evidence supports a role for caveolin-1 (Cav-1) in modulating drug sensitivity. This study aimed to investigate whether Cav-1 plays an important role in sensitivity to EGFR-TKIs in lung adenocarcinoma cells. Downregulation of Cav-1 in PC-9 cells were performed to investigate changes in sensitivity to EGFR-TKIs in vitro and in vivo. Knockdown of Cav-1 dramatically enhanced sensitivity to EGFR-TKIs by down-regulating phosphorylation of EGFR. These results suggest that Cav-1 may be a predictor of the poor efficacy of EGFR-TKIs treatment in lung adenocarcinoma with EGFR mutations.

Aberrant CpG Island Shore Region Methylation of CAV1 Is Associated with Tumor Progression and Poor Prognosis in Gastric Cardia Adenocarcinoma.

BACKGROUND AND AIMS: Caveolin-1 (CAV1) is a multifunctional scaffolding protein and plays an important role in tumorigenesis. However, the epigenetic changes of CAV1 in gastric cardia adenocarcinoma (GCA) have not been investigated so far. The purpose of this study was to clarify the contribution of critical CpG sites in CAV1 to progression/prognosis of GCA and to further elucidate the effect of critical CpG sites on the ectopic expression of ß-catenin in GCA. METHODS: Methylation-specific polymerase chain reaction (MSP) and bisulfite genomic sequencing (BGS) methods were, respectively, applied to examine the methylation status of CAV1. RT-PCR and immunohistochemistry methods were used to determine the mRNA and protein expression of CAV1 and ß-catenin. RESULTS: Decreased mRNA and protein expression of CAV1 were observed in GCA tumor tissues and were associated with hypermethylation of CpG island shore and transcription start site (TSS) regions in CAV1. Hypermethylation of the other two regions within CpG islands in CAV1 was observed both in tumor and corresponding adjacent tissues but was not related to the transcriptional inhibition of CAV1. The methylation status of CpG island shore region in CAV1 was associated with the ectopic expression of ß-catenin and was independently associated with survival in GCA patients. CONCLUSIONS: Hypermethylation of CpG island shore and TSS regions is cancer specific and is closely associated with reduced expression of CAV1. The CpG island shore methylation of CAV1 may play an important role in progression of GCA and may serve as a prognostic methylation biomarker for GCA patients.

TIM-3 promotes the metastasis of esophageal squamous cell carcinoma by targeting epithelial-mesenchymal transition via the Akt/GSK-3ß/Snail signaling pathway.

T-cell immunoglobulin and mucin domain-con-taining protein-3 (TIM-3), a negative regulator of antitumor immune response, has been demonstrated to be involved in the onset and progression of several types of malignancies. The present study aimed to determine whether and how TIM­3 plays such a role in esophageal squamous cell carcinoma (ESCC). TIM-3 expression was analyzed by immunohistochemistry and real­time fluorescence quantitative PCR (qRT­PCR) in ESCC and matched adjacent normal tissues. Functional experiments in vitro were performed to elucidate the effect of TIM­3 knockdown on the proliferation, apoptosis, migration, invasion and epithelial-mesenchymal transition (EMT) in Eca109 and TE­1 cell lines. Our data revealed that TIM­3 expression was significantly elevated at both the mRNA and protein levels in ESCC tissues compared with the levels in the matched adjacent normal tissues (both P<0.001). TIM­3 expression was significantly associated with lymph node metastasis (P=0.008), tumor­node­metastasis (TNM) stage (P=0.042) and depth of tumor invasion (P=0.042). In addition, we observed a strong correlation between high TIM­3 expression and a worse overall survival of ESCC patients (P=0.001). Functional study demonstrated that TIM­3 knockdown markedly inhibited proliferation, migration and invasion of ESCC cell lines without affecting apoptosis. In addition, TIM­3 depletion was associated with downregulation of matrix metalloproteinase (MMP)-9 and upregulation of tissue inhibitor of metalloproteinase (TIMP)-1, and with reversion of EMT, as reflected by higher levels of the epithelial marker E­cadherin and lower levels of the mesenchymal markers N­cadherin and vimentin. Further study found that TIM­3 depletion suppressed the signaling pathway involving p­Akt, p­GSK­3ß and Snail. Taken together, these results suggest that TIM­3 is a novel therapeutic target and prognostic biomarker for ESCC and promotes metastasis of ESCC by inducing EMT via, at least partially, the Akt/GSK-3ß/Snail signaling pathway.

Human Helicase RECQL4 Drives Cisplatin Resistance in Gastric Cancer by Activating an AKT-YB1-MDR1 Signaling Pathway.

Elevation of the DNA-unwinding helicase RECQL4, which participates in various DNA repair pathways, has been suggested to contribute to the pathogenicity of various human cancers, including gastric cancer. In this study, we addressed the prognostic and chemotherapeutic significance of RECQL4 in human gastric cancer, which has yet to be determined. We observed significant increases in RECQL4 mRNA or protein in >70% of three independent sets of human gastric cancer specimens examined, relative to normal gastric tissues. Strikingly, high RECQL4 expression in primary tumors correlated well with poor survival and gastric cancer lines with high RECQL4 expression displayed increased resistance to cisplatin treatment. Mechanistic investigations revealed a novel role for RECQL4 in transcriptional regulation of the multidrug resistance gene MDR1, through a physical interaction with the transcription factor YB1. Notably, ectopic expression of RECQL4 in cisplatin-sensitive gastric cancer cells with low endogenous RECQL4 was sufficient to render them resistant to cisplatin, in a manner associated with YB1 elevation and MDR1 activation. Conversely, RECQL4 silencing in cisplatin-resistant gastric cancer cells with high endogenous RECQL4 suppressed YB1 phosphorylation, reduced MDR1 expression, and resensitized cells to cisplatin. In establishing RECQL4 as a critical mediator of cisplatin resistance in gastric cancer cells, our findings provide a therapeutic rationale to target RECQL4 or the downstream AKT-YB1-MDR1 axis to improve gastric cancer treatment. Cancer Res; 76(10); 3057-66. ©2016 AACR.

Expression of caveolin-1 is correlated with lung adenocarcinoma proliferation, migration, and invasion.

Both tumor suppressor and tumor promoter roles, which are dependent on the tumor type, have been described for caveolin-1 (CAV-1). Because CAV-1 can modulate cell signaling, we tested the hypothesis that it regulates lung adenocarcinoma cell proliferation and metastasis via modulation of epidermal growth factor receptor (EGFR) activity. The lung adenocarcinoma cell line, GLC-82, was transfected with pcDNA3.1CAV-1 plasmid, before cell proliferation, migration, and invasion were analyzed. In the in vivo xenograft model, the relationship between the CAV-1 expression and EGFR phosphorylation and signaling was assessed by western blot analysis. The relationship between the CAV-1 as well as Ki67 expression and the clinicopathological characteristics of 68 lung adenocarcinoma patients was also examined using immunohistochemistry. Overexpression of CAV-1 significantly increased GLC-82 proliferation (p < 0.001), migration (p < 0.001), and invasion (p = 0.002) as well as EGFR and ERK phosphorylation (p < 0.05). The GLC-82/CAV-1 cell tumors were also significantly larger than those of control cells (all p ≤ 0.05). In lung adenocarcinoma patients, CAV-1 expression was positively correlated with lymph node metastasis and cancer stage. Finally, CAV-1 expression was associated with the expression of Ki-67, a marker of cell proliferation. CAV-1 enhanced GLC-82 cell proliferation, migration, and invasion possibly through EGFR and ERK signaling. Furthermore, the relationship of CAV-1 with Ki67 expression, a marker of proliferative capacity, in lung adenocarcinoma samples is suggestive of its role in disease progression. Further studies are required to confirm the role of CAV-1 in the metastasis of lung adenocarcinoma as well as its potential prognostic and therapeutic value.

Correlation between IGF2BP2 gene polymorphism and the risk of breast cancer in Chinese Han women.

OBJECTIVE: To investigate the correlations between the polymorphism of IGF2BP2, a diabetes predisposing gene, and breast cancer risk in Chinese female with Han nationality. METHOD: The genomic DNAs were extracted from the peripheral blood drawn from 564 female breast cancer patients and 394 healthy females of Han nationality. The polymorphism of IGF2BP2 gene rs4402960 was detected by a multiplex PCR-Ligase detection reaction (PCR-LDR) assay from genomic DNA. The correlations between genotype and breast cancer risk as well as clinicopathologic characteristics were compared. RESULTS: The differences are significant between genotype distribution of IGF2BP2 gene rs4402960 (P=0.009) and allele gene frequency from both disease and control groups. Both T gene carriers (GT+TT) (OR=1.462; 95% CI, 1.127-1.897) and T allele gene (OR=1.382; 95% CI, 1.116-1.710) significantly increase the risk of breast cancer. No considerable correlations were observed between the polymorphism of rs4402960 and the clinical pathological parameters, such as age at diagnosis, lymphatic metastasis, estrogen and progesterone receptor status, cerb-B2 receptor status, and tumor staging. CONCLUSIONS: The IGF2BP2 gene rs4402960 polymorphism increases the breast cancer risk of Chinese females with Han nationality, and is a breast cancer predisposing gene.

Predictive value of thymidylate synthase for the prognosis and survival of lung adenocarcinoma patients.

Chemotherapy represents an important treatment modality for lung adenocarcinoma. Thymidylate synthase (TS) is an essential enzyme in DNA synthesis, and its overexpression has been associated with reduced sensitivity to antifolate agents. The aim of the current study was to investigate the expression of TS and the effect on prognosis in lung adenocarcinoma patients. Adenocarcinoma and adjacent carcinoma tissues were resected from 100 patients with lung adenocarcinoma and the TS levels were detected by immunohistochemical analysis. The values for overall survival (OS) and disease-free survival (DFS) were determined using the Kaplan-Meier analysis. The results indicated that the TS protein was expressed predominantly in adenocarcinoma tissues, which exhibited higher TS expression compared with the adjacent tissues (P<0.001). The statistical analysis indicated that TS expression was associated with the clinical stage and history of smoking (P<0.05). The Kaplan-Meier analysis results indicated that the DFS and OS in patients with high TS expression levels were significantly shorter compared with those with low expression levels (P<0.05). In conclusion, the results from this study suggested that TS may serve as an independent predictive factor for survival rate, which may indicate the prognosis of lung adenocarcinoma patients.

Filamin A expression correlates with proliferation and invasive properties of human metastatic melanoma tumors: implications for survival in patients.

PURPOSE: Filamin A (FLNa) cross-links actin filaments into dynamic orthogonal networks and interacts with binding proteins of diverse cellular functions that are implicated in cell growth and motility regulation. Here, we tested the hypothesis that FLNa plays a role in cancer proliferation and metastasis via the regulation of epidermal growth factor receptor (EGFR) function. METHODS: Ectopic expression and knockdown of FLNa in human melanoma cell lines was performed to investigate changes in cellular proliferation, migration and invasion in vitro and tumor growth in a xenograft model in the mouse. The role of FLNa in EGFR expression and signaling was evaluated by Western blot. Immunohistochemistry was performed on histological sections of human melanoma tumors to determine whether an association existed between FLNa and overall survival. RESULTS: The depletion of FLNa significantly reduced the proliferation, migration and invasion of two melanoma cell lines in vitro and was associated with smaller tumors in a xenograft model in vivo. EGF-induced phosphorylation of EGFR and activation of the Raf-MEK-ERK cascade was negatively affected by the silencing of FLNa both in vitro and in vivo. Cancer patients with low melanoma tumor FLNa expression have improved survival benefit. CONCLUSION: These data indicate that enhanced tumorigenesis occurs through increase in EGF-induced EGFR activation in FLNa-expressing melanoma cells and that high FLNa levels are predictors of negative outcome for patients with melanoma tumors.

Pyrrolidine dithiocarbamate protects pancreatic ß-cells from oxidative damage through regulation of FoxO1 activity in type 2 diabetes rats.

Pyrrolidine dithiocarbamate (PDTC) can lower the blood glucose level and improve the insulin sensitivity in diabetic rats. However, the mechanisms underlying this effect of PDTC treatment in diabetic rats remained uncertain. In this study, we evaluated the mechanisms by which PDTC conferred protection against oxidative damage to pancreatic islet ß-cells in rats with experimental type 2 diabetes mellitus (DM). DM in the rats was elicited by long-term high-fat diet accompanied with a single intraperitoneal (i.p.) injection of a low dose of streptozotocin. After a 7-day administration of PDTC (50 mg/kg/day i.p.), blood glucose levels were measured and pancreatic tissues were collected for the determination of various biochemical and enzymatic activities using immunohistochemistry, immunofluorescence, and western blot techniques. The percentage of apoptotic pancreatic islet ß-cells was detected by flow cytometry. The results showed that diabetic rats had elevated blood glucose levels and insulin resistance, accompanied with an increase in malondialdehyde content, nitrotyrosine production, and inducible nitric oxide synthase expression. A decrease in superoxide dismutase and glutathione peroxidase activities was also observed in DM rats, culminating with elevated ß-cell apoptosis. PDTC treatment significantly reduced the oxidative damage and the ß-cell apoptosis, and also increased the insulin production through down-regulating FoxO1 acetylation and up-regulating nuclear PDX-1 level. These data suggested that PDTC can protect islet ß-cells from oxidative damage and improve insulin production through regulation of PDX-1 and FoxO1 in a DM rat model.

[Clinical significance of ROS1 rearrangements in non-small cell lung cancer].

Chromosomal rearrangements involving the ROS1 receptor tyrosine kinase gene have recently been described in multiple malignancies, including non-small cell lung cancer (NSCLC). ROS1 rearrangement defines a new molecular subset of NSCLC with the prevalence of ROS1 rearrangements around 1%-2%. ROS1-positive NSCLCs arise in young never-smokers with adenocarcinoma that are similar to those observed in patients with ALK-rearranged NSCLC. Crizotinib demonstrates in vitro activity and early clinical trial shows marked antitumor activity in ROS1-rearranged patients. The overall response rate is around 56% and the disease control rate at 8 weeks is about 76%. Further understanding the ROS1 fusions in the pathogenesis of NSCLC, methods to detect ROS1 rearrangements, and targeting ROS1-rearranged NSCLC patients with specific kinase inhibitors would lead to an era of personalized medicine.

Decreased expression and aberrant methylation of Gadd45G is associated with tumor progression and poor prognosis in esophageal squamous cell carcinoma.

The growth arrest DNA damage-inducible gene (Gadd45) family, which is composed of Gadd45A, Gadd45B, and Gadd45G, is involved in DNA damage response and cell growth arrest. The present study was to detect the role of Gadd45 gene family in esophageal cancer and the relationship of Gadd45G methylation to a series of pathological parameters in a large esophageal squamous cell carcinoma (ESCC) sample, in order to elucidate more information on the role of Gadd45 gene family with regard to the pathogenesis of ESCC. Frequent silencing of Gadd45G but not Gadd45A and Gadd45B were found in esophageal cancer cell lines and the silencing of Gadd45G may be reversed by 5-Aza-dC or TSA treatment in Eca109 cell line. The aberrant proximal promoter methylation of Gadd45G induces silencing of Gadd45G expression in Eca109 cell line. Gadd45A mRNA and protein expression in ESCC tumor tissues was significantly different compared to corresponding normal tissues. Decreased mRNA and protein expression of Gadd45G was observed in ESCC tumor tissues and was associated with Gadd45G proximal promoter methylation. Gadd45A or Gadd45B expression was not correlated with ESCC patients survival, while Gadd45G methylation status and protein expression were independently associated with ESCC patients' survival. These data indicated that Gadd45G may be a functional tumor suppressor and its inactivation through proximal promoter methylation may play an important role in ESCC carcinogenesis and reactivation of Gadd45G gene may has therapeutic potential and may be used as a prognostic marker for ESCC patients.