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1,776 result(s) for "Malignant transformation"
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The Microbiota-Derived Metabolite of Quercetin, 3,4-Dihydroxyphenylacetic Acid Prevents Malignant Transformation and Mitochondrial Dysfunction Induced by Hemin in Colon Cancer and Normal Colon Epithelia Cell Lines
Meat diet plays a pivotal role in colorectal cancer (CRC). Hemin, a metabolite of myoglobin, produced after meat intake, has been involved in CRC initiation. The compound, 3,4-dihydroxyphenylacetic acid (3,4HPAA) is a scarcely studied microbiota-derived metabolite of the flavonoid quercetin (QUE), which exert antioxidant properties. The aim of this study was to determine the protective effect of 3,4HPAA against malignant transformation (increased cell proliferation, decreased apoptosis, DNA oxidative damage and augmented reactive oxidative species (ROS) levels) and mitochondrial dysfunction induced by hemin in normal colon epithelial cells and colon cancer cells. The effect of 3,4HPAA was assessed in comparison to its precursor, QUE and to a known CRC protective agent, sulforaphane (SFN). The results showed that both, tumor and normal cells, exposed to hemin, presented increased cell proliferation, decreased caspase 3 activity and cytochrome c release, as well as augmented production of intracellular and mitochondrial ROS. In addition, hemin decreased the mitochondrial membrane potential (MMP) and the activity of complexes I and II of the electron transport chain. These effects of hemin were prevented by the action of 3,4HPAA. The metabolite showed to be more active than QUE and slightly less active than SFN. In conclusion, 3,4HPAA administration could represent a promising strategy for preventing malignant transformation and mitochondrial dysfunction in colon epithelia induced by hemin.
The Potential Key Role of the NRF2/NQO1 Pathway in the Health Effects of Arsenic Pollution on SCC
Arsenic is widely present in nature and is a common environmental poison that seriously damages human health. Chronic exposure to arsenic is a major environmental poisoning factor that promotes cell proliferation and leads to malignant transformation. However, its molecular mechanism remains unclear. In this study, we found that arsenite can promote the transformation of immortalized human keratinocyte cells (HaCaT) from the G0/G1 phase to S phase and demonstrated malignant phenotypes. This phenomenon is accompanied by obviously elevated levels of NRF2, NQO1, Cyclin E, and Cyclin-dependent kinase 2 (CDK2). Silencing the NRF2 expression with small interfering RNA (siRNA) in arsenite-transformed (T-HaCaT) cells was shown to reverse the malignant phenotype. Furthermore, the siRNA silencing of NQO1 significantly decreased the levels of the cyclin E-CDK2 complex, inhibiting the G0/G1 to S phase cell cycle progression and transformation to the T-HaCaT phenotypes. Thus, we hypothesized that the NRF2/NQO1 pathway played a key role in the arsenite-induced malignancy of HaCaT cells. By increasing the expression of Cyclin E-CDK2, the NRF2/NQO1 pathway can affect cell cycle progression and cell proliferation. A new common health effect mechanism of arsenic carcinogenesis has been identified; thus, it would contribute to the development of novel treatments to prevent and treat skin cancer caused by arsenic.
Spontaneous Occurrence of Various Types of Hepatocellular Adenoma in the Livers of Metabolic Syndrome-Associated Steatohepatitis Model TSOD Mice
Male Tsumura-Suzuki Obese Diabetes (TSOD) mice, a spontaneous metabolic syndrome model, develop non-alcoholic steatohepatitis and liver tumors by feeding on a standard mouse diet. Nearly 70% of liver tumors express glutamine synthetase (GS), a marker of hepatocellular carcinoma. In contrast, approximately 30% are GS-negative without prominent nuclear or structural atypia. In this study, we examined the characteristics of the GS-negative tumors of TSOD mice. Twenty male TSOD mice were sacrificed at 40 weeks and a total of 21 tumors were analyzed by HE staining and immunostaining of GS, liver fatty acid-binding protein (L-FABP), serum amyloid A (SAA), and beta-catenin. With immunostaining for GS, six (29%) tumors were negative. Based on the histological and immunohistological characteristics, six GS-negative tumors were classified into several subtypes of human hepatocellular adenoma (HCA). One large tumor showed generally similar findings to inflammatory HCA, but contained small atypical foci with GS staining and partial nuclear beta-catenin expression suggesting malignant transformation. GS-negative tumors of TSOD mice contained features similar to various subtypes of HCA. Different HCA subtypes occurring in the same liver have been reported in humans; however, the diversity of patient backgrounds limits the ability to conduct a detailed, multifaceted analysis. TSOD mice may share similar mechanisms of HCA development as in humans. It is timely to review the pathogenesis of HCA from both genetic and environmental perspectives, and it is expected that TSOD mice will make further contributions in this regard.
Human Papillomavirus Infection and EGFR Exon 20 Insertions in Sinonasal Inverted Papilloma and Squamous Cell Carcinoma
This study aimed to clarify the roles of high-risk human papillomavirus (HR-HPV) infection and epidermal growth factor receptor (EGFR) exon 20 mutations in sinonasal inverted papilloma (IP) and sinonasal squamous cell carcinoma (SNSCC). Samples were collected from 20 cases with IP, 7 with IP and squamous cell carcinoma (IP-SCC), and 20 with SNSCC and examined for HPV infection and EGFR exon 20 mutations. Low- or high-risk HPV DNA was observed in 25% of IP, 57.1% of IP-SCC, and 35% of SNSCC cases. Transcriptionally active HR-HPV infections in IP-SCC and SNSCC, accompanied by p16 overexpression, were observed in 28.5% and 25% of cases, respectively. Heterozygous EGFR exon 20 amino acid insertions (ex20ins), located between amino acids 768–774, were observed in 45% of IP, 28.5% of IP-SCC, and 0% of SNSCC and chronic sinusitis cases. EGFR phosphorylation sites were located at tyrosine (Y) 845, Y1068, Y1086, and Y1197 and induced PI3K/AKT/mTOR activation. The phosphorylation pattern of EGFR with ex20ins resembled that of HPV-related SNSCC and oropharyngeal cancer. The transcriptionally active HR-HPV infection and ex20ins might be responsible for the pathogenesis of IP-SCC cases with different fashions. Since IP-SCC might be a multifactorial disease, further investigation is needed to understand IP-SCC etiology.
Clinical Implication of Preoperative C-Reactive Protein/Albumin Ratio in Malignant Transformation of Intraductal Papillary Mucinous Neoplasm: A Propensity Score Analysis
Background: Inflammation-based scoring has been reported to be useful for predicting the recurrence and prognosis of various carcinomas. This study retrospectively investigated the relationship between inflammation-based score and intraductal papillary mucinous neoplasms (IPMNs). Methods: Between January 2013 and October 2018, we enrolled 417 consecutive patients with pancreatic tumors who received surgical resections at our hospital. The main outcome was the association between the preoperative inflammation-based score and their accuracy in predicting malignant transformation of IPMN. Results: Seventy six patients were eligible. Pathological findings indicated that 35 patients had low-grade dysplasia, 18 had high-grade dysplasia, and 23 had invasive carcinomas. As the C-reactive protein albumin ratio (CAR) was higher, malignant transformation of IPMNs also increased (p = 0.007). In comparing CARhigh and CARlow using cutoff value, the results using a propensity score analysis showed that the CARhigh group predicted malignant transformation of IPMNs (odds ratio, 4.18; 95% confidence interval, 1.37–12.8; p = 0.01). In the CARhigh group, disease-free survival (DFS) was significantly shorter (p = 0.04). In the worrisome features, the AUC for the accuracy of malignant transformation with CARhigh was 0.84 when combining with the MPD findings. Conclusions: Preoperative CAR could be a predictive marker of malignant transformation of IPMNs.
Inhibition of the Hedgehog Signaling Pathway Depresses the Cigarette Smoke-Induced Malignant Transformation of 16HBE Cells on a Microfluidic Chip
Background: The hedgehog signaling system (HHS) plays an important role in the regulation of cell proliferation and differentiation during the embryonic phases. However, little is known about the involvement of HHS in the malignant transformation of cells. This study aimed to detect the role of HHS in the malignant transformation of human bronchial epithelial (16HBE) cells. Methods: In this study, two microfluidic chips were designed to investigate cigarette smoke extract (CSE)-induced malignant transformation of cells. Chip A contained a concentration gradient generator, while chip B had four cell chambers with a central channel. The 16HBE cells cultured in chip A were used to determine the optimal concentration of CSE for inducing malignant transformation. The 16HBE cells in chip B were cultured with 12.25% CSE (Group A), 12.25% CSE + 5 μmol/L cyclopamine (Group B), or normal complete medium as control for 8 months (Group C), to establish the in vitro lung inflammatory-cancer transformation model. The transformed cells were inoculated into 20 nude mice as cells alone (Group 1) or cells with cyclopamine (Group 2) for tumorigenesis testing. Expression of HHS proteins was detected by Western blot. Data were expressed as mean ± standard deviation. The t-test was used for paired samples, and the difference among groups was analyzed using a one-way analysis of variance. Results: The optimal concentration of CSE was 12.25%. Expression of HHS proteins increased during the process of malignant transformation (Group B vs. Group A, F = 7.65, P < 0.05). After CSE exposure for 8 months, there were significant changes in cellular morphology, which allowed the transformed cells to grow into tumors in 40 days after being inoculated into nude mice. Cyclopamine could effectively depress the expression of HHS proteins (Group C vs. Group B, F = 6.47, P < 0.05) and prevent tumor growth in nude mice (Group 2 vs. Group 1, t = 31.59, P < 0.01). Conclusions: The activity of HHS is upregulated during the CSE-induced malignant transformation of 16HBE cells. Cyclopamine can effectively depress expression of HHS proteins in vitro and prevent tumor growth of the transformed cells in vivo.
Oral Potentially Malignant Disorders: Etiology, Pathogenesis, and Transformation Into Oral Cancer
(A) A representative diagram of changes occurring in buccal mucosa due to exposure to various carcinogenic factors. The red arrow shows the direction of changes associated with the progression of oral cancer. (B) The circular map shows the chromosomes involve in genetic alternation. Among oral diseases, oral cancer is a critical health issue due to its life-threatening potential. Globocan, in its 2020 report, estimated ∼0.37 million new cases of oral cancer, with the majority of them coming from the Asian continent. The WHO has anticipated a rise in the incidences of oral cancer in the coming decades. Various factors, such as genetic, epigenetic, microbial, habitual, and lifestyle factors, are closely associated with oral cancer occurrence and progression. Oral lesions, inherited genetic mutations (dyskeratosis congenital syndrome), and viral infections (HPV) are early signs of oral cancer. Lesions with dysplastic features have been categorized under oral potentially malignant disorders (OPMDs), such as oral leukoplakia, erythroplakia, oral submucous fibrosis (OSMF), and proliferative verrucous leukoplakia, are assumed to have a high risk of malignancy. The incidence and prevalence of OPMDs are recorded as being high in South-Asian countries. Early detection, prevention, and treatment of OPMDs are needed to prevent its malignant transformation into oral cancer. Many advanced diagnostic techniques are used to predict their progression and to assess the risk of malignant transformation. This communication provides insight into the importance of early detection and prevention of OPMDs.
Isolation of EpCAM+/CD133− hepatic progenitor cells
Progenitor cell-derived hepatocytes are critical for hepatocyte replenishment. Therefore, we established a line of human hepatic progenitor (HNK1) cells and determined their biological characteristics for experimental and therapeutic applications. HNK1 cells, isolated from human noncirrhotic liver samples with septal fibrosis, showed high expression of the hepatic progenitor cell (HPC) markers EpCAM, CK7, CK19, alpha-fetoprotein (AFP), CD90 (Thy1), and EFNA1. Expression of CD133 was very low. Ductular reactions at the periphery of cirrhotic nodules were immunohistochemically positive for these HPC markers, including EFNA1. Sodium butyrate, a differentiation inducer, induced hepatocyte-like morphological changes in HNK1 cells. It resulted in down-regulation of the hepatic progenitor cell markers EpCAM, CK7, CK19, AFP, and EFNA1 and up-regulation of mature hepatocyte markers, including albumin, CK8, and CK18. Furthermore, sodium butyrate treatment and a serial passage of HNK1 cells resulted in enhanced albumin secretion, ureagenesis, and CYP enzyme activity, all of which are indicators of differentiation in hepatocytes. However, HNK1 cells at passage 50 did not exhibit anchorage-independent growth capability and caused no tumors in immunodeficient mice, suggesting that they had no spontaneous malignant transformation ability. From this evidence, HNK1 cells were found to be EpCAM+/ CD133− hepatic progenitor cells without spontaneous malignant transformation ability. We therefore conclude that HNK1 cells could be useful for experimental and therapeutic applications.
In‐Tumor CRISPR ‐Cas9 Knockout Screening and Novel Therapy Development for Malignant Transformation of Ovarian Teratoma
Malignant transformation of mature cystic teratoma (MTMCT) of the ovary is a rare but aggressive malignancy for which no standardized chemotherapy or effective targeted therapies currently exist. To identify therapeutic vulnerabilities in MTMCT, we performed a genome‐wide CRISPR‐Cas9 knockout screen using the MTMCT‐derived NOSCC1 cell line. Two parallel selective pressures were applied: in vivo tumorigenicity in immunodeficient mice and cisplatin exposure in vitro. From this screen, 67 negatively selected genes were identified, among which SOD1 and NDUFB4 emerged as top candidates based on high basal expression levels and clinical relevance. Integration with spatial transcriptomic data from three independent MTMCT patient tumors further supported the prioritization of these targets. SOD1 was selected for further investigation due to the availability of known pharmacological inhibitors. Both siRNA‐mediated knockdown and small‐molecule inhibition of SOD1 using LCS‐1 significantly suppressed MTMCT cell proliferation in vitro by inducing oxidative stress and impairing cell cycle progression. This antiproliferative effect was reversed by co‐treatment with N ‐acetylcysteine, a reactive oxygen species scavenger. In vivo validation using patient‐derived xenograft models demonstrated that oral administration of LCS‐1 led to significant tumor growth suppression and increased expression of apoptotic and DNA damage markers, including cleaved caspase‐3 and γH2AX. These findings establish SOD1 as a critical vulnerability in MTMCT and provide preclinical evidence supporting redox modulation as a therapeutic strategy for this highly chemoresistant and understudied ovarian cancer subtype. Our integrative approach combining functional genomics, spatial transcriptomics, and pharmacologic validation offers a framework for the discovery of novel targets in rare gynecologic malignancies.
Effects of alpha-fetoprotein on the occurrence and progression of hepatocellular carcinoma
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. Alpha-fetoprotein (AFP) is considered as a diagnostic and prognostic tumorous marker for HCC, and up to 70% of HCC patients showed elevated serum levels of AFP. In the past two decades, evidences have shown that AFP not only is a tumorous biomarker for diagnosing HCC, but also plays a very complicated role in regulating proliferation, apoptosis, and autophagy and inhibiting the immune response of cells. Because AFP is significantly elevated during hepatocarcinogenesis, the role of AFP in the development of HCC is a scientific problem worthy of further exploration. In this review, we reviewed the effects of AFP on hepatocyte malignant transformation and the underlying mechanisms involved in the progression of HCC.