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Τετάρτη 11 Σεπτεμβρίου 2019

The chromene derivative 4-Clpgc inhibits cell proliferation and induces apoptosis in the K562 cell line

Abstract

Chronic myeloid leukemia (CML) is a malignant blood disease with a particular chromosomal aberration that is known as a common form of leukemia. The chromene family exhibits strong anti-cancer effects. Therefore, the effects of six members of the dihydropyrano [2,3-g] chromene family on cell toxicity and apoptosis induction in K562 cancer cells were investigated and compared with those of normal peripheral blood mononuclear cells (PBMCs). The K562 cells were cultured in the presence of the aforementioned chromene derivatives at concentrations of 40 to 200 μM for 24 to 72 h. The effects of these compounds on the growth and viability of the K562 cell line and PBMCs were studied through MTT assay. Furthermore, apoptosis induction was investigated using flow cytometry. Real-time PCR was used for relative quantification of BCL2, Bax, TP53 and BCR- ABL genes after 48 h of exposing K562 cells and PBMCs to 4-Clpgc. Based on the results, these chromene derivatives inhibited the growth of K562 cells. According to the obtained data, 4-Clpgc was the strongest compound with IC50 values of 102 ± 1.6 μM and 143 ± 9.41 μM in K562 cells and PBMCs, while pgc was the weakest one with IC50 levels of 278 ± 2.7 μM and 366 ± 47 μM in K562 cells and PBMCs (after 72 h), respectively. The results demonstrated that the apoptotic cell percentage in the control group increased from 6.09% to 84.10% and 17.2% to 20.06% in K562 cells and PBMCs after 48 h of treatment, respectively. Moreover, 4-Clpgc treatment increased the expression of Bax and TP53 genes by 42.74 and 35.88 folds in K562 cells and 9.60 and 7.75 folds in PBMCs, respectively. On the other hand, the expression of BCL2 was reduced by 1.47 and 1.38 folds in K562 cells and PBMCs, respectively. These compounds were associated with less toxic effects on normal cells, compared to the cancer cells. In conclusion, these derivatives can be considered as appropriate candidates for leukemia treatment.

Do drugs that target mTOR generate CCN2-mediated fibrogenic side effects?

Abstract

mTOR, the target of rapamycin, has been promoted as a potential target for cancers, transplantations and even lung fibrosis. However, paradoxically, targeting mTOR has been reported to result in profibrotic side effects. Some recent publications highlight why this might be.

Correction to: The official unified nomenclature adopted by the HGNC calls for the use of the acronyms, CCN1–6 , and discontinuation in the use of CYR61 , CTGF , NOV and WISP 1–3 respectively
The original version of this article unfortunately contained a mistake. In the Abstract section, a production query number (Q2) was inadvertently inserted within the new official gene names of the CCN proteins.

FGFR2-mediated phosphorylation of PTEN at tyrosine 240 contributes to the radioresistance of glioma

Abstract

Ionizing radiation (IR) is a standard-of-care treatment for glioma patients; however, the clinical efficacy is limited due to therapeutic resistance. A recent study published by Ma et al. (Cancer Cell 35:504–518, 2019) reported that the phosphorylation of phosphatase and tensin homolog (PTEN) at tyrosine 240 (pY240-PTEN) promotes the radioresistance of human glioma cells. After treatment with IR, the fibroblast growth factor receptor 2 (FGFR2)-mediated phosphorylation that generated pY240-PTEN could effectively promote the decondensation of chromatin through an interaction with Ki-67, leading to DNA damage repair and radioresistance. However, such promising findings need to be addressed in detail after considering the following points. (1) The authors should take into consideration whether or not the nuclear-cytoplasmic translocalization of PTEN occurs. (2) The roles of FGFR2-PTEN downregulation should be validated using both genetic and pharmacological inhibition models. (3) Some of the data shown by the authors are confusing and did not support the conclusion that patients with higher PTEN and FGFR2 expression were relatively IR resistant.

A FAILED CANCER PARADIGM: implications for cancer risk assessment and patients

Abstract

This commentary highlights the unique failures of environmental regulatory standards and related remedial actions to significantly reduce human cancer risks and the failure of cancer therapeutics to significantly impact cancer incidence and survival statistics despite vast resources allocated to both areas over the past half century. These dramatic institutional, scientific, medical, and regulatory failures suggest that current scientific understandings of cancer and its causation are seriously flawed and in need of a new objective re-appraisal.

Two decades (1998–2018) of research Progress on Hormesis: advancing biological understanding and enabling novel applications

Abstract

This commentary briefly summarizes the extraordinary resurgence of hormesis within the biological, biomedical, toxicological and risk assessment domains over the past two decades. It places this resurgence within the context of challenging the scientific validity of the threshold and linear dose responses. It argues that conducting research on mechanisms that actuate and regulate the stimulatory response features of hormesis will provide the knowledge needed to develop potentially transformational applications aimed at protecting and enhancing biological resiliency as well as treating/curing a multitude of diverse medical conditions.

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Bystander effectors of chondrosarcoma cells irradiated at different LET impair proliferation of chondrocytes

Abstract

While the dose-response relationship of radiation-induced bystander effect (RIBE) is controversial at low and high linear energy transfer (LET), mechanisms and effectors of cell-to-cell communication stay unclear and highly dependent of cell type. In the present study, we investigated the capacity of chondrocytes in responding to bystander factors released by chondrosarcoma cells irradiated at different doses (0.05 to 8 Gy) with X-rays and C-ions. Following a medium transfer protocol, cell survival, proliferation and DNA damages were quantified in bystander chondrocytes. The bystander factors secreted by chondrosarcoma cells were characterized. A significant and major RIBE response was observed in chondrocyte cells (T/C-28a2) receiving conditioned medium from chondrosarcoma cells (SW1353) irradiated with 0.1 Gy of X-rays and 0.05 Gy of C-ions, resulting in cell survivals of 36% and 62%, respectively. Micronuclei induction in bystander cells was observed from the same low doses. The cell survival results obtained by clonogenic assays were confirmed using impedancemetry. The bystander activity was vanished after a heat treatment or a dilution of the conditioned media. The cytokines which are well known as bystander factors, TNF-α and IL-6, were increased as a function of doses and LET according to an ELISA multiplex analysis. Together, the results demonstrate that irradiated chondrosarcoma cells can communicate stress factors to non-irradiated chondrocytes, inducing a wide and specific bystander response related to both doses and LET.

CLDN10 promotes a malignant phenotype of osteosarcoma cells via JAK1/Stat1 signaling

Abstract

In our previous study, the expression profile of tight junction (TJ) protein claudins (CLDNs) in human osteosarcoma (OS) cells was examined, and the data found the CLDN10 was high expressed in OS cells versus fetal osteoblast cells. Hence, we aim to determine the impacts and the molecular mechanisms of CLDN10 in the metastatic phenotype of OS. The exact expression profiles of CLDN10 and phosphorylated Janus kinase 1 (JAK1) in noncancerous bone tissues and OS tissues were detected via a western blotting and immunohistochemistry method. The OS cells with CLDN10 or JAK1 silencing was established via an RNA interference (RNAi) method, and an osteoblast cell line stably expressing CLDN10 was established via cell transfection. Then, the transfection effects and activation states of JAK1/ signal transducer and activator of transcription1 (Stat1) pathway in OS and osteoblast cells were detected via a western blotting assay. Moreover, the metastatic ability of osteoblast cells and OS cells in vitro were evaluated by means of a cell counting kit-8 (CCK8) assay, colony formation assay in soft agar, transwell assay and wound-healing experiment. The present data revealed that CLDN10 and phospho-JAK1 were up-regulated in OS tissues compared with noncancerous bone tissues. Genetic loss of CLDN10 or JAK1 inhibited the activation of the Stat1 and the malignant phenotype in OS cells. To sum up, our study suggested the CLDN10 enhanced the metastatic phenotype of OS cells via the activation of the JAK1/Stat1 signaling pathway.

Chronic shisha exposure alters phosphoproteome of oral keratinocytes

Abstract

Shisha smoking has been epidemiologically linked to oral cancer. However, few studies have investigated the pathobiology of shisha-induced cellular transformation. We studied the effects of chronic shisha exposure (8 months) in an in vitro model using immortalized, non-neoplastic oral keratinocytes (OKF6/TERT1). Quantitative proteomic and phosphoproteomic analyses were performed on OKF6/TERT1 cells treated with shisha extract for a period of 8 months. Pathway analysis was carried out to identify significantly enriched biological processes in shisha-treated cells. Chronic shisha exposure resulted in increased cell scattering phenomenon in OKF6/TERT1 cells. Data analysis revealed differential phosphorylation of 164 peptides (fold change ≥1.5, p ≤ 0.0.5) corresponding to 136 proteins. Proteins associated with mTORC1 and EIF4F complexes involved in initiating protein translation were seen to be enriched upon shisha treatment. Network analysis also highlighted downregulation of proteins involved in Type I interferon signaling in shisha-treated cells. Quantitative phosphoproteomic approach elucidated global perturbations to the molecular milieu of oral keratinocytes upon shisha exposure. Further studies are needed to validate putative targets in oral cancer patients with shisha smoking history.

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