Search results for "medicine.disease_cause"
showing 10 items of 6035 documents
Prevention of carcinogenesis and metastasis by Artemisinin-type drugs.
2018
Artemisia annua (sweet wormwood, qinhao) is an ancient Chinese herbal remedy for pyrexia. Nowadays, artemisinin (qinghaosu) and its derivatives belong to the standard therapies against malaria worldwide, and its discovery has led to the Nobel Prize in Physiology and Medicine to Youyou Tu in 2015. While most attention has been paid to the treatment of malaria, there is increasing evidence that Artemisinin-type drugs bear a considerable potential to treat and prevent cancer. Rather than reporting on therapy of cancer, this review gives a comprehensive and timely overview on the chemopreventive effects of artemisinin and its derivatives against carcinogenesis and metastasis formation, followin…
Colorectal Carcinogenesis: Role of Oxidative Stress and Antioxidants
2017
One of the contributory causes of colon cancer is the negative effect of reactive oxygen species on DNA repair mechanisms. Currently, there is a growing support for the concept that oxidative stress may be an important etiological factor for carcinogenesis. The purpose of this review is to elucidate the role of oxidative stress in promoting colorectal carcinogenesis and to highlight the potential protective role of antioxidants. Several studies have documented the importance of antioxidants in countering oxidative stress and preventing colorectal carcinogenesis. However, there are conflicting data in the literature concerning its proper use in humans, since these studies did not yield defin…
Gut vascular barrier impairment leads to intestinal bacteria dissemination and colorectal cancer metastasis to liver
2021
Metastasis is facilitated by the formation of a "premetastatic niche," which is fostered by primary tumor-derived factors. Colorectal cancer (CRC) metastasizes mainly to the liver. We show that the premetastatic niche in the liver is induced by bacteria dissemination from primary CRC. We report that tumor-resident bacteria Escherichia coli disrupt the gut vascular barrier (GVB), an anatomical structure controlling bacterial dissemination along the gut-liver axis, depending on the virulence regulator VirF. Upon GVB impairment, bacteria disseminate to the liver, boost the formation of a premetastatic niche, and favor the recruitment of metastatic cells. In training and validation cohorts of C…
Knockdown of hnRNPK leads to increased DNA damage after irradiation and reduces survival of tumor cells.
2017
Radiotherapy is an important treatment option in the therapy of multiple tumor entities among them head and neck squamous cell carcinoma (HNSCC). However, the success of radiotherapy is limited by the development of radiation resistances. Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is a cofactor of p53 and represents a potential target for radio sensitization of tumor cells. In this study, we analyzed the impact of hnRNPK on the DNA damage response after gamma irradiation. By yH2AX foci analysis, we found that hnRNPK knockdown increases DNA damage levels in irradiated cells. Tumor cells bearing a p53 mutation showed increased damage levels and delayed repair. Knockdown of hnRNPK appl…
Melanoma in the liver: Oxidative stress and the mechanisms of metastatic cell survival.
2020
Abstract Metastatic melanoma is a fatal disease with a rapid systemic dissemination. The most frequent target sites are the liver, bone, and brain. Melanoma metastases represent a heterogeneous cell population, which associates with genomic instability and resistance to therapy. Interaction of melanoma cells with the hepatic sinusoidal endothelium initiates a signaling cascade involving cytokines, growth factors, bioactive lipids, and reactive oxygen and nitrogen species produced by the cancer cell, the endothelium, and also by different immune cells. Endothelial cell-derived NO and H2O2 and the action of immune cells cause the death of most melanoma cells that reach the hepatic microvascul…
Comprehensive translational control of tyrosine kinase expression by upstream open reading frames
2016
Post-transcriptional control has emerged as a major regulatory event in gene expression and often occurs at the level of translation initiation. Although overexpression or constitutive activation of tyrosine kinases (TKs) through gene amplification, translocation or mutation are well-characterized oncogenic events, current knowledge about translational mechanisms of TK activation is scarce. Here, we report the presence of translational cis-regulatory upstream open reading frames (uORFs) in the majority of transcript leader sequences of human TK mRNAs. Genetic ablation of uORF initiation codons in TK transcripts resulted in enhanced translation of the associated downstream main protein-codin…
Growth differentiation factor 15 as a radiation-induced marker in oral carcinoma increasing radiation resistance.
2015
Background Growth differentiation factor 15 (GDF15) is involved in tumor pathogenesis of oral squamous cell carcinoma (OSCC). The aim of this study was an investigation of the potential influence of GDF15 on radioresistance of OSCC cells in vitro. Methods Oral squamous cell carcinoma cell lines were irradiated with 0, 2, or 6 Gy, and GDF15 expression in the supernatant per survived cell colony was examined with ELISA. Non-irradiated and OSCC cell lines irradiated with 6 Gy were evaluated for GDF15 expression using immunofluorescent staining. For further investigation of GDF15 effects on radioresistance, a GDF15 knockdown model in a human OSCC cell line was established, and apoptotic activit…
Targeting the chromosomal passenger complex subunit INCENP induces polyploidization, apoptosis and senescence in neuroblastoma
2019
Abstract Chromosomal passenger complex (CPC) has been demonstrated to be a potential target of cancer therapy by inhibiting Aurora B or survivin in different types of cancer including neuroblastoma. However, chemical inhibition of either Aurora B or survivin does not target CPC specifically due to off-target effects or CPC-independent activities of these two components. In a previous chromatin-focused siRNA screen, we found that neuroblastoma cells were particularly vulnerable to loss of INCENP, a gene encoding a key scaffolding component of the CPC. In this study, INCENP was highly expressed by neuroblastoma cells, and its expression decreased following retinoic acid–induced neuroblastoma …
In silico RNA-seq and experimental analyses reveal the differential expression and splicing of EPDR1 and ZNF518B genes in relation to KRAS mutations …
2016
Several drugs used for the treatment of colorectal cancer (CRC) are targeted at the epidermal growth factor receptor, but mutations in genes of the RAS family cause resistance to these drugs. Thus, extensive research is being carried out to counterbalance this resistance. The G13D mutation of KRAS is common in humans, and we previously reported that this mutation results in the epigenetic modification of hnRNP proteins, involved in RNA splicing. As aberrant splicing often results in oncogenicity, the present study aimed to identify the genes which show altered splicing patterns in connection with the G13D KRAS mutation. To accomplish this, we first carried out an in silico analysis of RNA-s…
Doxorubicin anti-tumor mechanisms include Hsp60 post-translational modifications leading to the Hsp60/p53 complex dissociation and instauration of re…
2017
Hsp60 is a pro-carcinogenic chaperonin in certain tumor types by interfering with apoptosis and with tumor cell death. In these tumors, it is not known whether or not doxorubicin anti-tumor effects include a blockage of the pro-carcinogenic action of this protein. We used the human lung mucoepidermoid cell line NCI-H292 and different doses of doxorubicin to measure cell viability, cell cycle progression, cell senescence indicators, Hsp60 levels and its post-translational modifications as well as the release of the chaperonin into the extracellular environment. Cell viability was reduced in relation to doxorubicin dose and this was paralleled by the appearance of cell senescence markers. Con…