Based on the evidence that hemochromatosis, an iron-overload disease, drives hepatocellular carcinoma, we hypothesized that chronic exposure to excess iron, either due to genetic or environmental causes, predisposes a...Based on the evidence that hemochromatosis, an iron-overload disease, drives hepatocellular carcinoma, we hypothesized that chronic exposure to excess iron, either due to genetic or environmental causes, predisposes an individual to cancer. Using pancreatic cancer as our primary focus, we employed cell culture studies to interrogate the connection between excess iron and cancer, and combined in vitro and in vivo studies to explore the connection further. Ferric ammonium citrate was used as an exogenous iron source. Chronic exposure to excess iron induced epithelial-mesenchymal transition(EMT) in normal and cancer cell lines, loss of p53, and suppression of p53 transcriptional activity evidenced from decreased expression of p53 target genes(p21, cyclin D1, Bax, SLC7A11). To further extrapolate our cell culture data, we generated EL-KrasG12D( EL-Kras) mouse(pancreatic neoplastic mouse model) expressing Hfe+/+ and Hfe-/- genetic background. p53 target gene expression decreased in EL-Kras/Hfe-/- mouse pancreas compared to EL-Kras/Hfe+/+ mouse pancreas. Interestingly, the incidence of acinar-to-ductal metaplasia and cystic pancreatic neoplasms(CPN) decreased in EL-Kras/Hfe-/- mice, but the CPNs that did develop were larger in these mice than in EL-Kras/Hfe+/+ mice. In conclusion, these in vitro and in vivo studies support a potential role for chronic exposure to excess iron as a promoter of more aggressive disease via p53 loss and SLC7A11 upregulation within pancreatic epithelial cells.展开更多
The clinical and endoscopic features of amyloid lightchain(AL) amyloidosis are diverse and mimic various other diseases.Endoscopically,few reports on submucosal hematomas of the gastrointestinal(GI) tract are availabl...The clinical and endoscopic features of amyloid lightchain(AL) amyloidosis are diverse and mimic various other diseases.Endoscopically,few reports on submucosal hematomas of the gastrointestinal(GI) tract are available in the literature.Here,we report two cases of AL amyloidosis presenting as submucosal hematomas in the absence of clinical disease elsewhere in the body.The 2 cases were referred to our hospital because of hematochezia.The endoscopic findings in both cases were similar in submucosal hematoma formation.However,the clinical courses differed.In the first case,there was no evidence of systemic amyloidosis and the disease was conservatively managed.In the second case,the disease progressed to systemic amyloidosis and the patient died within a short time.We conclude that the endoscopic detection of a submucosal hematoma in the setting of GI bleeding should raise suspicion of AL amyloidosis.Referral to a hematologist should be done immediately for treatment while the involvement is limited to the GI tract.展开更多
基金The authors acknowledge the financial support received from the National Institute of Health(CA223271)The authors would also like to thank Dr.Ming Tsao(Ontario Cancer Institute)for the human pancreatic ductal epithelial(HPDE)cell line.
文摘Based on the evidence that hemochromatosis, an iron-overload disease, drives hepatocellular carcinoma, we hypothesized that chronic exposure to excess iron, either due to genetic or environmental causes, predisposes an individual to cancer. Using pancreatic cancer as our primary focus, we employed cell culture studies to interrogate the connection between excess iron and cancer, and combined in vitro and in vivo studies to explore the connection further. Ferric ammonium citrate was used as an exogenous iron source. Chronic exposure to excess iron induced epithelial-mesenchymal transition(EMT) in normal and cancer cell lines, loss of p53, and suppression of p53 transcriptional activity evidenced from decreased expression of p53 target genes(p21, cyclin D1, Bax, SLC7A11). To further extrapolate our cell culture data, we generated EL-KrasG12D( EL-Kras) mouse(pancreatic neoplastic mouse model) expressing Hfe+/+ and Hfe-/- genetic background. p53 target gene expression decreased in EL-Kras/Hfe-/- mouse pancreas compared to EL-Kras/Hfe+/+ mouse pancreas. Interestingly, the incidence of acinar-to-ductal metaplasia and cystic pancreatic neoplasms(CPN) decreased in EL-Kras/Hfe-/- mice, but the CPNs that did develop were larger in these mice than in EL-Kras/Hfe+/+ mice. In conclusion, these in vitro and in vivo studies support a potential role for chronic exposure to excess iron as a promoter of more aggressive disease via p53 loss and SLC7A11 upregulation within pancreatic epithelial cells.
文摘The clinical and endoscopic features of amyloid lightchain(AL) amyloidosis are diverse and mimic various other diseases.Endoscopically,few reports on submucosal hematomas of the gastrointestinal(GI) tract are available in the literature.Here,we report two cases of AL amyloidosis presenting as submucosal hematomas in the absence of clinical disease elsewhere in the body.The 2 cases were referred to our hospital because of hematochezia.The endoscopic findings in both cases were similar in submucosal hematoma formation.However,the clinical courses differed.In the first case,there was no evidence of systemic amyloidosis and the disease was conservatively managed.In the second case,the disease progressed to systemic amyloidosis and the patient died within a short time.We conclude that the endoscopic detection of a submucosal hematoma in the setting of GI bleeding should raise suspicion of AL amyloidosis.Referral to a hematologist should be done immediately for treatment while the involvement is limited to the GI tract.
