Exogenous bacterial DnaK increases protein kinases activity in human cancer cell lines

Abstract

Background Studies of molecular mechanisms underlying tumor cell signaling highlighted a critical role for kinases in carcinogenesis and cancer progression. To this regard, protein kinases regulates a number of critical cellular pathways by adding phosphate groups to specific substrates. For this reason, their involvement in the complex interactions between the human microbiota and cancer cells to determine therapy and tumor progression outcome is becoming increasingly relevant. Mycoplasmas are components of the normal human microbiota, and several species have also been associated to human diseases, including certain cancers. It is also important to note that Mycoplasmas and their proteins are a component of the common tumor microenvironment. In addition, several epidemiological, in vivo and in vitro studies indicate a close involvement of Mycoplasmas in cellular transformation and cancer progression. Methods In this study, we investigate the effect of exogenous Mycoplasma DnaK on kinases activity by treating in vitro four different eukaryotic cancer cell lines, namely lung and prostate cancer, colon adenocarcinoma, and neuroblastoma. Phosphorylation of kinases and specific substrates was measured at 20 and 60 min. Results Kinome analysis of our data indicates that Mycoplasma DnaK promotes the dysregulation of the activity of specific kinases and their substrates, with a known involvement in carcinogenesis and cancer progression. Conclusions Given the similarity in structure and amino acid composition of this protein with other bacterial DnaKs we provide a novel mechanism whereby components of the human microbiota and present in the tumor microenvironment are able to deregulate phosphorylation events occurring during carcinogenesis and cancer progression.

Mycoplasma DnaK increases DNA copy number variants in vivo

“…On the one hand, DnaK would enter the oocyte or the sperm similarly to what we and other previously demonstrated in other cell types with both DnaK ( 13 , 20 ) and other HSP70 proteins ( 28 ), in turn generating DNA CNVs by interacting with and hampering the activity of important proteins responsible for DNA integrity ( 29 ). On the other hand, interaction of exogenous DnaK with the embryo could trigger abnormal cellular activation, as previously shown by our group and others in different in vitro cellular models ( 61 , 72 – 74 ). This abnormal cellular activation could subsequently lead to abnormal fetal development, which could potentially impact fertility.…”

“…Mycoplasmas and Ureaplasmas , like all bacteria, secrete a number of proteins, including DnaK ( 22 , 23 , 26 ). This bacterial chaperone protein is very similar in amino acid composition among Mycoplasmas and Ureaplasmas ( 13 ), it can be taken up by bystander cells ( 20 , 13 ), dysregulate protein kinases activity, ( 61 ) and hamper the activity of proteins essential for DNA repair and maintenance ( 20 , 13 ). Proper DNA repair to preserve genomic integrity is an essential process during oogenesis and spermatogenesis ( 62 , 63 ), and given the presence of Mycoplasmas and Ureaplasmas in both the female and male reproductive tract, it is conceivable that DnaK could interfere with this process.…”

Bacterial DnaK reduces the activity of anti-cancer drugs cisplatin and 5FU

“…Notably, their engagement with DNA repair components can render cells more susceptible to transformation following damage, a phenomenon we have recently demonstrated in vivo [ 66 ]. Moreover, the inappropriate activation of protein kinases due to DnaK interaction may lead to abnormal cellular activation [ 42 ]. We have also found that the presence of DnaK is associated with an increase in Reactive Oxygen Species and pro-inflammatory cytokine production, which may contribute to cancer onset and progression [ 66 ].…”

“…Recombinant exogenous DnaKs-V5 used in this study were obtained as previously described [ 30 , 42 ]. Briefly, both eM-DnaK and eF-DnaK sequences were inserted into a cloning vector for the expression of the protein fused to a V5-tag peptide.…”

Prostate Microbiota and Prostate Cancer: A New Trend in Treatment

“…The chaperone protein DnaK of mycoplasma has carcinogenic activity by binding to poly (ADP-ribose transferase) and p53, thus inhibiting DNA repair and p53 function (101). Exogenous DNAK in the tumor microenvironment can activate some kinase-related transduction pathways in a cell-specific way, such as the Akt1/2/3 group and p70S6 kinase group of the AGC family, the AMPKERK2 group of the CAMK family, and a-1-2-3 group of the CMGC family, so as to promote carcinogenesis and cancer progression (102). In addition, the protein p37 encoded by mycoplasma can promote the invasion of cancer cells in a dose-dependent manner (103).…”