The distribution of phospholipids across the inner membrane (IM) of Gram-negative bacteria is unknown. We demonstrate that the IMs of Escherichia coli and Yersinia pseudotuberculosis are asymmetric, with a 75%/25% (cytoplasmic/periplasmic leaflet) distribution of phosphatidylethanolamine (PE) in rod-shaped cells and an opposite distribution in E. coli filamentous cells. In initially filamentous PE-lacking E. coli cells, nascent PE appears first in the periplasmic leaflet. As the total PE content increases from nearly zero to 75%, cells progressively adopt a rod shape and PE appears in the cytoplasmic leaflet of the IM. The redistribution of PE influences the distribution of the other lipids between the leaflets. This correlates with the tendency of PE and cardiolipin to regulate antagonistically lipid order of the bilayer. The results suggest that PE asymmetry is metabolically controlled to balance temporally the net rates of synthesis and translocation, satisfy envelope growth capacity, and adjust bilayer chemical and physical properties.

The main goal of this study is to consider SLC34A2 as a potential prognostic marker of oncological diseases using the mutational, expression, and survival data of cancer studies which are publicly available online. We collected data from four databases (cBioPortal, The Cancer Genome Atlas; cBioPortal, Genie; International Cancer Genome Consortium; ArrayExpress). In total, 111,283 samples were categorized according to 27 tumor locations. Ninety-nine functionally significant missense mutations and twelve functionally significant indel mutations in SLC34A2 were found. The most frequent mutations were SLC34A2-ROS1, p.T154A, p.P506S/R/L, p.G257A/E/R, p.S318W, p.A396T, p.P410L/S/H, p.S461C, p.A473T/V, and p.Y503H/C/F. The upregulation of SLC34A2 was found in samples of myeloid, bowel, ovarian, and uterine tumors; downregulation was found in tumor samples of breast, liver, lung, and skin cancer tumors. It was found that the life expectancy of breast and thymus cancer patients with an SLC34A2 mutation is lower, and it was revealed that SLC34A2 overexpression reduced the life span of patients with brain, ovarian, and pancreatic tumors. Thereby, for these types of oncological diseases, the mutational profile of SLC34A2 can be a potential prognostic marker for breast and thymus cancers, and the upregulation of SLC34A2 can be a potential prognostic marker for brain, ovarian, and pancreatic cancers.

The high mortality rate from ovarian cancer is due to the asymptomatic nature of the course of the disease, which leads to the diagnosis of ovarian cancer in later stages. The sodium-dependent phosphate transporter NaPi2b encoded by SLC34A2 gene is expressed in 80–90% of epithelial ovarian cancers and used as a target for therapeutic antibodies XMT-1536, and XMT-1592, which are derived from MX35 antibodies and used in clinical trials for the treatment of ovarian and lung cancers. In this work, we aimed to evaluate NaPi2b as a molecular marker for diagnostics and predicting the course and outcome of ovarian cancer disease.

The chemoresistance of tumor cells is one of the most urgent challenges in modern oncology and in pancreatic cancer, in which this problem is the most prominent. Therefore, the identification of new chemosensitizing co-targets may be a path toward increasing chemotherapy efficacy. In this work, we performed high-performance in vitro knockout CRISPR/Cas9 screening to find potential regulators of the sensitivity of pancreatic cancer. For this purpose, MIA PaCa-2 cells transduced with two sgRNA libraries (“cell cycle/nuclear proteins genes” and “genome-wide”) were screened by oxaliplatin and cisplatin. In total, 173 candidate genes were identified as potential regulators of pancreatic cancer cell sensitivity to oxaliplatin and/or cisplatin; among these, 25 genes have previously been reported, while 148 genes were identified for the first time as potential platinum drug sensitivity regulators. We found seven candidate genes involved in pancreatic cancer cell sensitivity to both cisplatin and oxaliplatin. Gene ontology enrichment analysis reveals the enrichment of single-stranded DNA binding, damaged DNA binding pathways, and four associated with NADH dehydrogenase activity. Further investigation and validation of the obtained results by in vitro, in vivo, and bioinformatics approaches, as well as literature analysis, will help to identify novel pancreatic cancer platinum sensitivity regulators.

Purpose. To investigate a frequency of antibody response to SEREX-identified medullary breast carcinoma autoantigens ZRF1 and KRR1 in sera of breast cancer patients taking into account clinical and molecular characteristics of tumors for opening of new perspectives in creation of minimally invasive immunological tests for cancer diagnostics.Methods. Enzyme-linked immunosorbent assay and bioinformatics analysis.Results. Increased frequency of antibody response was found in sera of breast cancer patients to ZRF and KRR1 antigens. The antibody response to these antigens was higher in sera of patients with invasive ductal carcinoma than in sera of patients with other histological types of breast tumors. Moreover, more frequent antibody response to ZRF antigen was found in sera of patients with less aggressive tumors. The sequence analysis of ZRF1 antigen SEREX clones obtained from cDNA libraries of different tumors demonstrates that they encode different protein isoforms.Conclusion. Tumor-associated antigens KRR1 and ZRF1 and their cognate autoantibodies could be considered as potential molecular markers of breast cancer which need to be further investigated.

NaPi2b is a sodium-dependent phosphate transporter that belongs to the SLC34 family of transporters which is mainly responsible for phosphate homeostasis in humans. Although NaPi2b is widely expressed in normal tissues, its overexpression has been demonstrated in ovarian, lung, and other cancers. A valuable set of antibodies, including L2 (20/3) and MX35, and its humanized versions react strongly with an antigen on the surface of ovarian and other carcinoma cells. Although the topology of NaPi2b was predicted in silico, no direct experimental data are available for the orientation of NaPi2b extracellular domains in cancer cells. The presented results of antibody mapping of untagged NaPi2b in live ovarian carcinoma cells OVCAR-4 provide a platform for current and future epitope-based cancer therapies and serological diagnostics.