BACKGROUND Pancreatic,periampullary/ampullary,and choledochal adenocarcinomas are aggressive malignancies with a poor prognosis.Immune checkpoint blockade is a promising treatment option for several tumor types.H long...BACKGROUND Pancreatic,periampullary/ampullary,and choledochal adenocarcinomas are aggressive malignancies with a poor prognosis.Immune checkpoint blockade is a promising treatment option for several tumor types.H long terminal repeatassociating 2(HHLA2),which is analogous to programmed death-ligand 1(PDL1),is a recently discovered member of the B7/cluster of differentiation 28 family and is expressed in many malignancies.AIM To analyze the expression of HHLA2 and its association with the pathologic biomarkers that predict sensitivity to immunotherapy.METHODS Ninety-two adenocarcinoma cases located in the pancreas,ampulla,and distal common bile duct were identified.This study assessed 106 pancreaticoduodenectomy and distal/total pancreatectomy samples that were delivered to Ankara City Hospital between 2019 and 2021.Immunohistochemistry was conducted to examine the expression of DNA mismatch repair(MMR),PD-L1,and HHLA2 proteins.RESULTS Patients with high HHLA2 expression had a higher mean age than those with low expression.Low HHLA2 expression was associated with high perineural invasion.HHLA2 expression was low in pathological stage T3(pT)3 cases and high in pathological stage T1,T2,and T4 cases.There was no correlation between HHLA2 expression and the expression of MMR proteins and PD-L1.CONCLUSION Evaluation of HHLA2 expression in microsatellite stable and PD-L1-negative tumors may be useful for predicting the response of individuals to immunotherapy and may serve as a novel therapeutic target for immunotherapy in advanced-stage disease.展开更多
Pathogenic mutations involving DNA repeat expansions are responsible for over 20 different neuronal and neuromuscular diseases. All result from expanded tracts of repetitive DNA sequences(mostly microsatellites) that ...Pathogenic mutations involving DNA repeat expansions are responsible for over 20 different neuronal and neuromuscular diseases. All result from expanded tracts of repetitive DNA sequences(mostly microsatellites) that become unstable beyond a critical length whentransmitted across generations. Nearly all are inherited as autosomal dominant conditions and are typically associated with anticipation. Pathologic unstable repeat expansions can be classified according to their length, repeat sequence, gene location and underlying pathologic mechanisms. This review summarizes the current contribution of mutant pluripotent stem cells(diseased human embryonic stem cells and patient-derived induced pluripotent stem cells) to the research of unstable repeat pathologies by focusing on particularly large unstable noncoding expansions. Among this class of disorders are Fragile X syndrome and Fragile X-associated tremor/ataxia syndrome, myotonic dystrophy type 1 and myotonic dystrophy type 2, Friedreich ataxia and C9 related amyotrophic lateral sclerosis and/or frontotemporal dementia, Facioscapulohumeral Muscular Dystrophy and potentially more. Common features that are typical to this subclass of conditions are RNA toxic gain-of-function, epigenetic loss-of-function, toxic repeat-associated non-ATG translation and somatic instability. For each mechanism we summarize the currently available stem cell based models, highlight how they contributed to better understanding of the related mechanism, and discuss how they may be utilized in future investigations.展开更多
文摘BACKGROUND Pancreatic,periampullary/ampullary,and choledochal adenocarcinomas are aggressive malignancies with a poor prognosis.Immune checkpoint blockade is a promising treatment option for several tumor types.H long terminal repeatassociating 2(HHLA2),which is analogous to programmed death-ligand 1(PDL1),is a recently discovered member of the B7/cluster of differentiation 28 family and is expressed in many malignancies.AIM To analyze the expression of HHLA2 and its association with the pathologic biomarkers that predict sensitivity to immunotherapy.METHODS Ninety-two adenocarcinoma cases located in the pancreas,ampulla,and distal common bile duct were identified.This study assessed 106 pancreaticoduodenectomy and distal/total pancreatectomy samples that were delivered to Ankara City Hospital between 2019 and 2021.Immunohistochemistry was conducted to examine the expression of DNA mismatch repair(MMR),PD-L1,and HHLA2 proteins.RESULTS Patients with high HHLA2 expression had a higher mean age than those with low expression.Low HHLA2 expression was associated with high perineural invasion.HHLA2 expression was low in pathological stage T3(pT)3 cases and high in pathological stage T1,T2,and T4 cases.There was no correlation between HHLA2 expression and the expression of MMR proteins and PD-L1.CONCLUSION Evaluation of HHLA2 expression in microsatellite stable and PD-L1-negative tumors may be useful for predicting the response of individuals to immunotherapy and may serve as a novel therapeutic target for immunotherapy in advanced-stage disease.
文摘Pathogenic mutations involving DNA repeat expansions are responsible for over 20 different neuronal and neuromuscular diseases. All result from expanded tracts of repetitive DNA sequences(mostly microsatellites) that become unstable beyond a critical length whentransmitted across generations. Nearly all are inherited as autosomal dominant conditions and are typically associated with anticipation. Pathologic unstable repeat expansions can be classified according to their length, repeat sequence, gene location and underlying pathologic mechanisms. This review summarizes the current contribution of mutant pluripotent stem cells(diseased human embryonic stem cells and patient-derived induced pluripotent stem cells) to the research of unstable repeat pathologies by focusing on particularly large unstable noncoding expansions. Among this class of disorders are Fragile X syndrome and Fragile X-associated tremor/ataxia syndrome, myotonic dystrophy type 1 and myotonic dystrophy type 2, Friedreich ataxia and C9 related amyotrophic lateral sclerosis and/or frontotemporal dementia, Facioscapulohumeral Muscular Dystrophy and potentially more. Common features that are typical to this subclass of conditions are RNA toxic gain-of-function, epigenetic loss-of-function, toxic repeat-associated non-ATG translation and somatic instability. For each mechanism we summarize the currently available stem cell based models, highlight how they contributed to better understanding of the related mechanism, and discuss how they may be utilized in future investigations.
