Autophagy and mTOR pathways in mouse embryonic stem cell, lung cancer and somatic fibroblast cell lines

Differences and similarities in biophysical and biological characteristics between U87 MG glioblastoma and astrocyte cells

Current cancer studies focus on molecular-targeting diagnostics and interactions with surroundings; however, there are still gaps in characterization based on topological differences and elemental composition. Glioblastoma (GBM cells; GBMCs) is an astrocytic aggressive brain tumor. At the molecular level, GBMCs and astrocytes may differ, and cell elemental/topological analysis is critical for identifying potential new cancer targets. Here, we used U87 MG cells for GBMCS. U87 MG cell lines, which are frequently used in glioblastoma research, are an important tool for studying the various features and underlying mechanisms of this aggressive brain tumor. For the first time, atomic force microscopy (AFM), scanning electron microscopy (SEM) accompanied by energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) are used to report the topology and chemistry of cancer (U87 MG) and healthy (SVG p12) cells. In addition, F-actin staining and cytoskeleton-based gene expression analyses were performed. The degree of gene expression for genes related to the cytoskeleton was similar; however, the intensity of F-actin, anisotropy values, and invasion-related genes were different. Morphologically, GBMCs were longer and narrower while astrocytes were shorter and more disseminated based on AFM. Furthermore, the roughness values of these cells differed slightly between the two call types. In contrast to the rougher astrocyte surfaces in the lamellipodial area, SEM-EDS analysis showed that elongated GBMCs displayed filopodial protrusions. Our investigation provides considerable further insight into rapid cancer cell characterization in terms of a combinatorial spectroscopic and microscopic approach.

Different types of cell death and their shift in shaping disease

Cell death is the irreversible stop of life. It is also the basic physiological process of all organisms which involved in the embryonic development, organ maintenance and autoimmunity of the body. In recent years, we have gained more comprehension of the mechanism in cell death and have basically clarified the different types of "programmed cell death", such as apoptosis, necroptosis, autophagy, and pyroptosis, and identified some key genes in these processes. However, in these previous studies, the conversion between different cell death modes and their application in diseases are rarely explored. To sum up, although many valued discoveries have been discovered in the field of cell death in recent years, there are still many unknown problems to be solved in this field. Facts have proved that cell death is a very complex game, and a series of core players have the ability to destroy the delicate balance of the cell environment, from survival to death, from anti-inflammatory to pro-inflammatory. With the thorough research of the complex regulatory mechanism of cell death, there will certainly be exciting new research in this field in the next few years. The sake of this paper is to emphasize the complex mechanism of overturning the balance between different cell fates and provide relevant theoretical basis for the connection between cell death transformation and disease treatment in the future.

USP5 knockdown alleviates lung cancer progression via activating PARP1-mediated mTOR signaling pathway

BACKGROUND

With the rapidly increasing morbidity and mortality, lung cancer has been considered one of the serious malignant tumors, affecting millions of patients globally. Currently, the pathogenesis of lung cancer remains unclear, hindering the development of effective treatment. This study aims to investigate the mechanisms of lung cancer and develop an effective therapeutic approach for intervention in preventing lung cancer progress.

METHODS

The USP5 levels are detected in lung cancerous and paracancerous tissue by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting methods to explore their roles in lung cancer progression. MTT, colony assay, and transwell chamber approaches are employed to measure cell viability, proliferation, and migration, respectively. Further, flow cytometry experiments are performed to examine the effect of USP5 on lung cancer. Finally, the investigations in vivo are executed using the mice subcutaneous tumor model to identify the effect of USP5 in promoting lung cancer development.

RESULTS

Notably, USP5 is highly expressed in lung cancer, USP5 overexpression promoted the proliferation and migration in the lung cancer cell lines, H1299 and A549, while knockdown of USP5 inhibited these via regulating the PARP1-mediated mTOR signaling pathway. Furthermore, the subcutaneous tumors model was established in C57BL/6 mice, and the volume of subcutaneous tumors was significantly reduced after silencing USP5, while increased after USP5 overexpression and decreased significantly with shRARP1 treatment at the same time.

CONCLUSIONS

Together, USP5 could promote the progression of lung cancer cells by mTOR signaling pathway and interacting with PARP1, indicating that USP5 may become a new target for lung cancer treatment.

The regulatory effects of clomiphene and tamoxifen on mTOR and LC3-II expressions in relation to autophagy in experimental polycystic ovary syndrome (PCOS)

BACKGROUND

Polycystic ovary syndrome (PCOS) is a metabolic disease that causes infertility due to anovulation in women in reproductive age. It is known that clomiphene citrate (CC) and tamoxifen citrate (TMX) induce ovulation in women with PCOS. In this study, we aimed to investigate the effects of CC and TMX on the autophagy pathway in PCOS.

METHODS AND RESULTS

Experimental PCOS model was induced by letrozole (1 mg/kg) in rats by gavage for 21 days. After the last letrozole administration, rats were treated TMX (1 mg/kg) or CC (1 mg/kg) for 5 days. At the end of the experimental procedures, rats in all groups were sacrificed and ovarian tissues were removed. It was observed that mRNA and protein expressions of LC3-II were significantly higher in TMX and CC groups than control and PCOS groups (p < 0.05), while mRNA and protein expressions of mTOR in TMX and CC groups were found significantly lower than control and PCOS groups (p < 0.05).

CONCLUSIONS

In conclusion, present study suggests that TMX and CC induce autophagy in ovaries with PCOS. Autophagy is a promising target for understanding pathophysiology of this disease and for developing more effective and safe new protocols for the treatment of PCOS-related anovulation.

mTOR-autophagy promotes pulmonary senescence through IMP1 in chronic toxicity of methamphetamine

It is growingly concerned about methamphetamine (MA)-induced lung toxicity. IMP1 is identified as a key molecule for cell life processes, but the role of IMP1 in MA-induced senescence remains unclear. The purpose of this study was to investigate whether chronic exposure to MA can cause autophagy and senescence of the lungs, whether there are interactions between Mammalian target of rapamycin (mTOR) and IMP1 and whether IMP1 is involved in pulmonary senescence promoted by mTOR-autophagy. The rats were randomly divided into control group and MA group, following by H&E staining, immunohistochemistry staining and Western blot. The alveolar epithelial cells were proceeded by ß-galactosidase staining, cell cycle detection, transfection and co-immunoprecipitation. Long-term exposure to MA led to the thickening of alveolar septum and more compact lungs. MA promoted the conversion of LC3-I to LC3-II and inhibited the activation of mTOR to induce autophagy. Bioinformatics and co-immunoprecipitation results presented the interactions between IMP1 and mTOR. MA induced cell senescence by decreasing IMP1, up-regulating p21 and p53, arresting cell cycle and increasing SA-β-gal. Overexpression of IMP1 reduced p21 and SA-β-gal to inhibit the senescence of alveolar epithelial cells. These results demonstrated that mTOR-autophagy promotes pulmonary senescence through IMP1 in chronic toxicity of methamphetamine.

Downregulation of hsa_circ_0007580 inhibits non-small cell lung cancer tumorigenesis by reducing miR-545-3p sponging

Non-small cell lung cancer (NSCLC) is a highly malignant tumor. Many circular RNAs (circRNAs) are reportedly in regulating the progression of NSCLC. To identify potential therapeutic targets for NSCLC, we conducted a bioinformatics analysis of circRNAs differentially expressed between NSCLC tissues and adjacent normal tissues. Hsa_circ_0007580 was upregulated in NSCLC tumor tissues, and the expression of its host gene (protein kinase Ca) correlated negatively with overall survival. Short-hairpin RNAs were used to knock down hsa_circ_0007580 in NSCLC cells, and gene and protein levels were measured with qRT-PCR and Western blotting, respectively. NSCLC cell proliferation, migration and apoptosis were evaluated with CCK-8 assays, Ki-67 staining, Transwell assays and flow cytometry, respectively. Knocking down hsa_circ_0007580 inhibited proliferation and invasion by NSCLC cells and induced their apoptosis. Dual luciferase reporter assays indicated that miR-545-3p can bind to hsa_circ_0007580 (suggesting that hsa_circ_0007580 sponges miR-545-3p) and to protein kinase Ca (suggesting that miR-545-3p directly inhibits this gene). In a xenograft tumor model, downregulating hsa_circ_0007580 inhibited NSCLC tumorigenesis by inactivating p38/mitogen-activated protein kinase signaling. Thus, silencing hsa_circ_0007580 notably inhibited NSCLC progression in vitro and in vivo, suggesting this circRNA could be a novel treatment target for NSCLC.

Induction of Lysosome Membrane Permeabilization as a Therapeutic Strategy to Target Pancreatic Cancer Stem Cells

Despite significant efforts to improve pancreatic ductal adenocarcinoma (PDAC) clinical outcomes, overall survival remains dismal. The poor response to current therapies is partly due to the existence of pancreatic cancer stem cells (PaCSCs), which are efficient drivers of PDAC tumorigenesis, metastasis and relapse. To find new therapeutic agents that could efficiently kill PaCSCs, we screened a chemical library of 680 compounds for candidate small molecules with anti-CSC activity, and identified two compounds of a specific chemical series with potent activity in vitro and in vivo against patient-derived xenograft (PDX) cultures. The anti-CSC mechanism of action of this specific chemical series was found to rely on induction of lysosomal membrane permeabilization (LMP), which is likely associated with the increased lysosomal mass observed in PaCSCs. Using the well characterized LMP-inducer siramesine as a tool molecule, we show elimination of the PaCSC population in mice implanted with tumors from two PDX models. Collectively, our approach identified lysosomal disruption as a promising anti-CSC therapeutic strategy for PDAC.

The CLN3 gene and protein: What we know

Background

One of the most important steps taken by Beyond Batten Disease Foundation in our quest to cure juvenile Batten (CLN3) disease is to understand the State of the Science. We believe that a strong understanding of where we are in our experimental understanding of the CLN3 gene, its regulation, gene product, protein structure, tissue distribution, biomarker use, and pathological responses to its deficiency, lays the groundwork for determining therapeutic action plans.

Objectives

To present an unbiased comprehensive reference tool of the experimental understanding of the CLN3 gene and gene product of the same name.

Methods

BBDF compiled all of the available CLN3 gene and protein data from biological databases, repositories of federally and privately funded projects, patent and trademark offices, science and technology journals, industrial drug and pipeline reports as well as clinical trial reports and with painstaking precision, validated the information together with experts in Batten disease, lysosomal storage disease, lysosome/endosome biology.

Results

The finished product is an indexed review of the CLN3 gene and protein which is not limited in page size or number of references, references all available primary experiments, and does not draw conclusions for the reader.

Conclusions

Revisiting the experimental history of a target gene and its product ensures that inaccuracies and contradictions come to light, long‐held beliefs and assumptions continue to be challenged, and information that was previously deemed inconsequential gets a second look. Compiling the information into one manuscript with all appropriate primary references provides quick clues to which studies have been completed under which conditions and what information has been reported. This compendium does not seek to replace original articles or subtopic reviews but provides an historical roadmap to completed works.