Oncogenes, Proto-Oncogenes, and Lineage Restriction of Cancer Stem Cells

In principle, an oncogene is a cellular gene (proto-oncogene) that is dysfunctional, due to mutation and fusion with another gene or overexpression. Generally, oncogenes are viewed as deregulating cell proliferation or suppressing apoptosis in driving cancer. The cancer stem cell theory states that most, if not all, cancers are a hierarchy of cells that arises from a transformed tissue-specific stem cell. These normal counterparts generate various cell types of a tissue, which adds a new dimension to how oncogenes might lead to the anarchic behavior of cancer cells. It is that stem cells, such as hematopoietic stem cells, replenish mature cell types to meet the demands of an organism. Some oncogenes appear to deregulate this homeostatic process by restricting leukemia stem cells to a single cell lineage. This review examines whether cancer is a legacy of stem cells that lose their inherent versatility, the extent that proto-oncogenes play a role in cell lineage determination, and the role that epigenetic events play in regulating cell fate and tumorigenesis.

The N-terminal and central domains of CoV-2 nsp1 play key functional roles in suppression of cellular gene expression and preservation of viral gene expression

Nonstructural protein 1 (nsp1) is the first viral protein synthesized during coronavirus (CoV) infection and is a key virulence factor that dampens the innate immune response. It restricts cellular gene expression through a combination of inhibiting translation by blocking the mRNA entry channel of the 40S ribosomal subunit and by promoting mRNA degradation. We performed a detailed structure-guided mutational analysis of CoV-2 nsp1 coupled with in vitro and cell-based functional assays, revealing insight into how it coordinates these activities against host but not viral mRNA. We found that residues in the N-terminal and central regions of nsp1 not involved in docking into the 40S mRNA entry channel nonetheless stabilize its association with the ribosome and mRNA, thereby enhancing its restriction of host gene expression. These residues are also critical for the ability of mRNA containing the CoV-2 leader sequence to escape translational repression. Notably, we identify CoV-2 nsp1 mutants that gain the ability to repress translation of viral leader-containing transcripts. These data support a model in which viral mRNA binding functionally alters the association of nsp1 with the ribosome, which has implications for drug targeting and understanding how engineered or emerging mutations in CoV-2 nsp1 could attenuate the virus.

Regulation of host and viral promoters during human cytomegalovirus latency via US28 and CTCF

Viral latency is an active process during which the host cell environment is optimized for latent carriage and reactivation. This requires control of both viral and host gene promoters and enhancers often at the level of chromatin, and several viruses co-opt the chromatin organiser CTCF to control gene expression during latency. While CTCF has a role in the latencies of alpha- and gamma-herpesviruses, it was not known whether CTCF played a role in the latency of the beta-herpesvirus human cytomegalovirus (HCMV). Here, we show that HCMV latency is associated with increased CTCF expression and CTCF binding to the viral major lytic promoter, the major immediate early promoter (MIEP). This increase in CTCF binding is dependent on the virally encoded G protein coupled receptor, US28, and contributes to suppression of MIEP-driven transcription, a hallmark of latency. Furthermore, we show that latency-associated upregulation of CTCF represses expression of the neutrophil chemoattractants S100A8 and S100A9 which we have previously shown are downregulated during HCMV latency. As with downregulation of the MIEP, CTCF binding to the enhancer region of S100A8/A9 drives their suppression, again in a US28-dependent manner. Taken together, we identify CTCF upregulation as an important mechanism for optimizing latent carriage of HCMV at both the levels of viral and cellular gene expression.

A New Surface Charge Neutralizing Nano-Adjuvant to Potentiate Polymyxins in Killing Mcr-1 Mediated Drug-Resistant Escherichia coli

Resistance to polymyxins when treating multidrug-resistant (MDR) Gram-negative bacterial infections limit therapeutic options. Here, we report the synthesis of a nickel (Ni) doped Zinc oxide (NZO) combined with black phosphorus (BP) (NZB) nanocomposite and its synergistic action with polymyxin B (PolB) against polymyxin-resistant Escherichia coli harboring mobilized colistin resistance (mcr-1) gene. NZB and PolB combination therapy expressed a specific and strong synergy against Mcr-1 expressing E. coli cells. The underlying mechanism of the synergy is the charge neutralization of the E. coli cell surface by NZB, resulting in a more feasible incorporation of PolB to E. coli. The synergistic concentration of NZB with PolB was proved biocompatible. Thus, the NZB is the first biocompatible nano-adjuvant to polymyxins against polymyxin-resistant E. coli cells, recognizing the physical status of bacteria instead of known adjuvants targeting cellular gene products. Therefore, NZB has the potential to revive polymyxins as leading last-resort antibiotics to combat polymyxin-resistant Gram-negative bacterial infections.

PredicTF: a tool to predict bacterial transcription factors in complex microbial communities

Transcription Factors (TFs) are proteins that control the flow of genetic information by regulating cellular gene expression. Here we describe PredicTF, a first platform supporting the prediction and classification of novel bacterial TF in complex microbial communities. We evaluated PredicTF using a two-step approach. First, we tested PredictTF’s ability to predict TFs for the genome of an environmental isolate. In the second evaluation step, PredicTF was used to predict TFs in a metagenome and 11 metatranscriptomes recovered from a community performing anaerobic ammonium oxidation (anammox) in a bioreactor. PredicTF is open source pipeline available at https://github.com/mdsufz/PredicTF.

Single cell transcriptomics reveals a heterogeneous cellular response to BKV infection

BKV is a human polyomavirus that is generally harmless but can cause devastating disease in immunosuppressed individuals. BKV infection of renal cells is a common problem for kidney transplant patients undergoing immunosuppressive therapy. In cultured primary human renal proximal tubule epithelial cells (RPTE), BKV undergoes a productive infection. The BKV-encoded large T antigen (LT) induces cell cycle entry, resulting in the upregulation of numerous genes associated with cell proliferation. Consistently, microarray and RNA-seq experiments performed in bulk infected cell populations identified several proliferation-related pathways that are upregulated by BKV. These studies revealed few genes that are downregulated. In this study, we analyzed viral and cellular transcripts in single mock or BKV-infected cells. We found that the levels of viral mRNAs vary widely among infected cells, resulting in different levels of LT and viral capsid protein expression. Cells expressing the highest levels of viral transcripts account for approximately 20% of the culture and have a gene expression pattern that is distinct from cells expressing lower levels of viral mRNAs. Surprisingly, cells expressing low levels of viral mRNA do not progress with time to high expression, suggesting that the two cellular responses are determined prior to or shortly following infection. Finally, comparison of cellular gene expression patterns of cells expressing high levels of viral mRNA with mock-infected cells, or with cells expressing low levels of viral mRNA, revealed previously unidentified pathways that are downregulated by BKV. Among these are pathways associated with drug metabolism and detoxification, TNF-signaling, energy metabolism, and translation. IMPORTANCE The outcome of viral infection is determined by the ability of the virus to redirect cellular systems towards progeny production countered by the ability of the cell to block these viral actions. Thus, an infected culture consists of thousands of cells, each fighting their own individual battle. Bulk measurements, such as PCR or RNA-seq, measure the average of these individual responses to infection. Single cell transcriptomics provides a window to the one-on-one battle between BKV and each cell. Our studies reveal that only a minority of infected cells are overwhelmed by the virus and produce large amounts of BKV mRNAs and proteins, while the infection appears to be restricted in the remaining cells. Correlation of viral transcript levels with cellular gene expression patterns reveals pathways manipulated by BKV that may play a role in limiting infection.

Metabolic mind and primordial instinct. From biochemistry to the embodiment applied to nutrition. Vegan integrated diet. One step forward.

In this era when the whole world is in a psychotic recession, where Covid-19 feeds on human substrate unprepared for the "pandemic state", the only real salvation is listening to one's metabolism. It is not a title from Hollywood, it is a real lockdown of the human race which, once again in history, demonstrates its ineptitude which, by syllogism, would mean a lack of resilient property. A resilience not in relation to a material, but metaphorically projected to a reflection where man, the only protagonist endowed with intellect, once again makes the same mistakes by entering the usual loop that punctually repeats itself every decade. Mind and body seem to be no longer distinguishable and have lost the structuring quality that their role determined and made possible constructive actions on the world. The distance between observer and observed, between mind and matter, has faded as if to cruelly provoke a loss of consciousness and identity crisis, hindering the creation of new models, theories and correlations that allow to act in this world. Neuroscience is shedding light on crucial aspects of the nervous system, such as the modalities of neuronal growth and selection of unused synapses (Edelman 1987), as well as the effects of learning or repeated and recorded experiences, on metabolism and cellular gene transcription ( Kandel, Schartz, Jessel, 1991). Psychosomatics with a view to multifactoriality and interdependence for mind-body study are the key points for the study presented here.