-
Clinical Cancer Research : An Official... Jun 2024Even though BRAF fusions are increasingly detected in standard multigene next-generation sequencing panels, few reports have explored their structure and impact on...
BACKGROUND
Even though BRAF fusions are increasingly detected in standard multigene next-generation sequencing panels, few reports have explored their structure and impact on clinical course.
PATIENTS/METHODS
We collected data from patients with BRAF fusion-positive cancers identified through a genotyping protocol of 97,024 samples. Fusions were characterized and reviewed for oncogenic potential (in-frame status, non-BRAF partner gene, intact BRAF kinase domain).
RESULTS
We found 241 BRAF fusion-positive tumors from 212 patients with 82 unique 5' fusion partners spanning 52 histologies. 39 fusion partners were not previously reported, and 61 were identified once. BRAF fusion incidence was enriched in pilocytic astrocytomas, gangliomas, low-grade neuroepithelial tumors, and acinar cell carcinoma of the pancreas. 24 patients spanning multiple histologies were treated with MAPK-directed therapies of which 20 were evaluable for RECIST. Best response was partial response (N=2), stable disease (N=11), and progressive disease (N=7). The median time on therapy was 1 month with MEK plus BRAF inhibitors ([N=11], range 0-18 months) and 8 months for MEK inhibitors ([N=14], range 1-26 months). 9 patients remained on treatment for longer than 6 months [pilocytic astrocytomas (N=6), Erdheim-Chester disease (N=1), extraventricular neurocytoma (N=1), melanoma (N=1)]. Fifteen patients had acquired BRAF fusions.
CONCLUSIONS
BRAF fusions are found across histologies and represent an emerging actionable target. BRAF fusions have a diverse set of fusion partners. Durable responses to MAPK therapies were seen, particularly in pilocytic astrocytomas. Acquired BRAF fusions were identified after targeted therapy underscoring the importance of post-progression biopsies to optimize treatment at relapse in these patients.
PubMed: 38922339
DOI: 10.1158/1078-0432.CCR-23-3981 -
Pathology Jun 2024KRAS G12C is the most common KRAS mutation in non-small cell lung carcinoma (NSCLC), for which targeted therapy has recently been developed. From the 732 cases of NSCLC...
KRAS G12C is the most common KRAS mutation in non-small cell lung carcinoma (NSCLC), for which targeted therapy has recently been developed. From the 732 cases of NSCLC that underwent next-generation sequencing at the Department of Anatomical Pathology, Liverpool Hospital, between July 2021 and May 2023, we retrieved 83 (11%) consecutive cases of KRAS G12C mutated NSCLC, and analysed their clinical, pathological, and molecular features. Of the 83 cases of KRAS G12C mutated NSCLC, there were 46 (55%) men and 37 (45%) women, with mean age of 72 years. Of the 49 cases with known clinical information, 94% were current or ex-smokers, and 49% were stage IV at diagnosis with median survival of 12 months. Sixty-three percent were histology cases and the remainder were cytology cases. Eighty-two percent were non-mucinous adenocarcinomas, with conventional histology including lepidic, acinar, solid, single cells and micropapillary patterns, and 62% were poorly differentiated. There were five (6%) cases of mucinous adenocarcinoma, one case of pleomorphic carcinoma and one case of high-grade fetal adenocarcinoma. TTF1 was positive in the majority (89%) of cases. Nineteen (23%) cases had TP53 co-mutation, and these cases had trends towards higher PD-L1 expression, poor differentiation, and presentation as stage IV disease, but the differences were not statistically significant. KRAS G12C mutated NSCLCs almost exclusively occurred in smokers and were mostly non-mucinous adenocarcinomas with conventional histological patterns which ranged from well to poorly differentiated. Around a quarter had TP53 co-mutation, the histological impacts and immune profile of which need to be assessed in a larger study.
PubMed: 38918148
DOI: 10.1016/j.pathol.2024.04.002 -
Gastroenterology Jun 2024Pancreatic ducts form an intricate network of tubules that secrete bicarbonate and drive acinar secretions into the duodenum. This network is formed by centroacinar...
BACKGROUND AND AIMS
Pancreatic ducts form an intricate network of tubules that secrete bicarbonate and drive acinar secretions into the duodenum. This network is formed by centroacinar cells, terminal, intercalated, intracalated ducts, and the main pancreatic duct. Ductal heterogeneity at the single-cell level has been poorly characterized; therefore, our understanding of the role of ductal cells in pancreas regeneration and exocrine pathogenesis has been hampered by the limited knowledge and unexplained diversity within the ductal network.
METHODS
We used scRNA-seq to comprehensively characterize mouse ductal heterogeneity at single-cell resolution of the entire ductal epithelium from centroacinar cells to the main duct. Moreover, we used organoid cultures, injury models and pancreatic tumor samples to interrogate the role of novel ductal populations in pancreas regeneration and exocrine pathogenesis.
RESULTS
We have identified the coexistence of 15 ductal populations within the healthy pancreas and characterized their organoid formation capacity and endocrine differentiation potential. Cluster isolation and subsequent culturing let us identify ductal cell populations with high organoid formation capacity and endocrine and exocrine differentiation potential in vitro, including Wnt-responsive-population, ciliated-population and FLRT3 cells. Moreover, we have characterized the location of these novel ductal populations in healthy pancreas, chronic pancreatitis, and tumor samples. The expression of WNT-responsive, IFN-responsive and EMT-population markers increases in chronic pancreatitis and tumor samples.
CONCLUSIONS
In light of our discovery of previously unidentified ductal populations, we unmask potential roles of specific ductal populations in pancreas regeneration and exocrine pathogenesis. Thus, novel lineage tracing models are needed to investigate ductal specific populations in vivo.
PubMed: 38908487
DOI: 10.1053/j.gastro.2024.06.008 -
Diabetes Jun 2024Exocrine-to-endocrine crosstalk in the pancreas is crucial to maintain beta cell function. However, the molecular mechanisms underlying this crosstalk are largely...
Exocrine-to-endocrine crosstalk in the pancreas is crucial to maintain beta cell function. However, the molecular mechanisms underlying this crosstalk are largely undefined. Trefoil factor 2 (Tff2) is a secreted factor known to promote the proliferation of beta cells in vitro, but its physiological role in vivo in the pancreas is unknown. Also, it remains unclear which pancreatic cell type expresses Tff2 protein. We therefore created a mouse model with a conditional knockout of Tff2 in the murine pancreas. We find that the Tff2 protein is preferentially expressed in acinar but not ductal or endocrine cells. Tff2 deficiency in the pancreas reduces beta cell mass on embryonic day 16.5. However, homozygous mutant mice are born without a reduction of beta cells and with acinar Tff3 compensation by day 7. When mice are aged to 1 year, both male and female homozygous and male heterozygous mutants develop impaired glucose tolerance without affected insulin sensitivity. Perifusion analysis reveals that the second phase of glucose-stimulated insulin secretion from islets is reduced in aged homozygous mutant compared to controls. Collectively, these results demonstrate a previously unknown role of Tff2 as an exocrine acinar cell-derived protein required for maintaining functional endocrine beta cells in mice.
PubMed: 38905124
DOI: 10.2337/db23-0490 -
BioRxiv : the Preprint Server For... Jan 2024induction of alcoholic chronic pancreatitis (ACP) causes significant acinar damage, increased fibroinflammatory response, and heightened activation of cyclic response...
BACKGROUND AND AIMS
induction of alcoholic chronic pancreatitis (ACP) causes significant acinar damage, increased fibroinflammatory response, and heightened activation of cyclic response element binding protein 1 (CREB) when compared with alcohol (A) or chronic pancreatitis (CP) mediated pancreatic damage. However, the study elucidating the cooperative interaction between CREB and the oncogenic (*) in promoting pancreatic cancer progression with ACP remains unexplored.
METHODS
Experimental ACP induction was established in multiple mouse models, followed by euthanization of the animals at various time intervals during the recovery periods. Tumor latency was determined in these mice cohorts. Here, we established CREB deletion ( ) in (KC) genetic mouse models (KCC). Western blot, phosphokinase array, and qPCR were used to analyze the pancreata of , and mice. The pancreata of ACP-induced mice were subjected to single-cell RNA sequencing (scRNAseq). Further studies involved conducting lineage tracing and acinar cell explant cultures.
RESULTS
ACP induction in mice had detrimental effects on the pancreatic damage repair mechanism. The persistent existence of acinar cell-derived ductal lesions demonstrated a prolonged state of hyperactivated CREB. Persistent CREB activation leads to acinar cell reprogramming and increased pro-fibrotic inflammation in mice. Acinar-specific ablation reduced advanced PanINs lesions, hindered tumor progression, and restored acinar cell function in ACP-induced mouse models.
CONCLUSIONS
Our findings demonstrate that CREB cooperates with * to perpetuate an irreversible ADM and PanIN formation. Moreover, CREB sustains oncogenic activity to promote the progression of premalignant lesions toward cancer in the presence of ACP.
PubMed: 38903082
DOI: 10.1101/2024.01.05.574376 -
Biochimica Et Biophysica Acta.... Jun 2024The pancreas is a glandular organ with both endocrine and exocrine functions. Researchers have investigated the roles of several Rab proteins, which are major regulators...
The pancreas is a glandular organ with both endocrine and exocrine functions. Researchers have investigated the roles of several Rab proteins, which are major regulators of membrane trafficking, in pancreatic exocytosis of zymogen granules in exocrine cells, also known as acinar cells. However, detailed molecular mechanisms mediated by Rab proteins are not fully understood. RASEF/Rab45 is an atypical Rab GTPase that contains N-terminal EF-hand and coiled-coil domains, as well as a C-terminal Rab-GTPase domain. In this study, we investigated the in vivo role of RASEF in pancreatic acinar cells using RASEF-knockout (KO) mice. Morphological analyses revealed that pancreatic acinar cells in RASEF-KO mice had an increased number of zymogen granules and abnormal formations of organelles, such as the endoplasmic reticulum (ER) and lysosomes. Biochemical analyses showed that ER proteins were decreased, but digestive enzymes were increased in the RASEF-KO pancreas. Moreover, trypsinogen was activated and co-localized with the endo-lysosomal marker LAMP1 in RASEF-KO pancreas. Upon cerulein administration to induce acute pancreatitis, impaired enzyme release from the pancreas was observed in the serum of RASEF-KO mice. These findings suggest that RASEF likely regulates the formation and sorting of zymogen granules and secretion of digestive enzymes by pancreatic acinar cells.
PubMed: 38901651
DOI: 10.1016/j.bbadis.2024.167310 -
Tissue & Cell Jun 2024Hydroxychloroquine (HCQ), an antimalarial drug widely used in treating rheumatoid disorders. Many side effects have been reported with HCQ administration indicating its...
Effects of prolonged hydroxychloroquine use on the pancreatic tissue and expected ameliorative effect of lactoferrin in rats (biochemical, histological, and morphometric study).
Hydroxychloroquine (HCQ), an antimalarial drug widely used in treating rheumatoid disorders. Many side effects have been reported with HCQ administration indicating its hazardous effects on various organs. No previous studies reported the effect of long-term administration of oral HCQ on pancreatic tissue. Our study assessed pancreatic tissues functional and histopathological alterations following prolonged oral administration of HCQ. We also investigated the possible ameliorative effects of the lactoferrin (LF) coadministration with HCQ in adult male albino rats. Forty adult male Wister albino rats were divided into: negative control, LF positive control (2 g/kg), HCQ-treated (200 mg/kg), and HCQ+LF treated. Biochemical, histological, immunohistochemical, and morphometric analyses of the pancreatic tissues were conducted. Our findings revealed that prolonged oral administration of HCQ induced significant disruption of the pancreatic acinar architecture, enlarged congested islets of Langerhans, and elevated plasma insulin, amylase, and lipase levels. Interestingly, LF administration ameliorated the deleterious effects of prolonged HCQ administration on pancreatic tissue of adult male albino rats. In conclusion, prolonged oral administration of HCQ induced pancreatic tissue damage in rats, while LF attenuates HCQ-induced pancreatic injury. Our results emphasized the necessity of prescribing HCQ with caution, considering both dosage and treatment duration.
PubMed: 38889555
DOI: 10.1016/j.tice.2024.102439 -
Arkhiv Patologii 2024The purpose of this work was to evaluate gene amplification in the substrate of prostate acinar adenocarcinoma at various Gleason scores and various stages of the...
OBJECTIVE
The purpose of this work was to evaluate gene amplification in the substrate of prostate acinar adenocarcinoma at various Gleason scores and various stages of the disease, taking into account the morphological characteristics of the tumor.
MATERIAL AND METHODS
The number of cases in the study was 82, including the control group - 12 cases. Morphological assessment included: determination of the total Gleason score, grading group, assessment of lymphovascular/perineural invasion, and architectural characteristics of the tumor. Gene amplification was assessed by FISH using the c-MYC (8q24)/SE8 probe.
RESULTS
In all cases of the study group, amplification of the c-MYC gene was detected in the tumor, with a significant difference from the control group (<0.05). When assessing cases with 4-6 fold copies of the gene, significant differences were established between patients with stages II and III of the disease and stage IV (10.0 and 13.5 versus 30.0) (<0.05). Cluster amplification of the c-MYC gene was detected with equal frequency in groups of patients with stages III and IV of the disease, while in stage II of the disease, the event almost did not occur (<0.05). A significant increase in the level of c-MYC gene amplification was found in groups with advanced stages of the disease (<0.02). Non-cluster amplification significantly distinguishes T4M0 and T4M1 stage patients from the rest with a significant increase in the score (<0.05). In the metastatic stage of the disease, there was an increase c-MYC gene amplification compared to the non-metastatic stage (<0.02). The copy number of the c-MYC gene was significantly higher in cases with perineural and lymphovascular invasion, as well as in cases of cribriform tumor organization (<0.05).
CONCLUSION
Amplification of the gene in prostate tumor cells is associated with advanced stages of the disease (T4M0 and T4M1) with an increase in the copy number of the gene during the metastatic stage of the process. It was found that increased amplification of the gene distinguishes groups of patients whose tumors exhibit perineural and lymphovascular invasion, as well as a cribriform pattern of tumor organization.
Topics: Humans; Male; Prostatic Neoplasms; Proto-Oncogene Proteins c-myc; Gene Amplification; Middle Aged; Aged; Genes, myc; Carcinoma, Acinar Cell
PubMed: 38881003
DOI: 10.17116/patol20248603130 -
Molecular Therapy : the Journal of the... Jun 2024Efferocytosis, the clearance of apoptotic cells by macrophages, plays a crucial role in inflammatory responses and effectively prevents secondary necrosis. However, the...
Efferocytosis, the clearance of apoptotic cells by macrophages, plays a crucial role in inflammatory responses and effectively prevents secondary necrosis. However, the mechanisms underlying efferocytosis in acute pancreatitis (AP) remain unclear. In this study, we demonstrated the presence of efferocytosis in injured human and mouse pancreatic tissues. We also observed significant upregulation of CD47, an efferocytosis-related the "do not eat me" molecule in injured acinar cells. Subsequently, we used CRISPR-Cas9 gene editing, anti-adeno-associated virus (AAV) gene modification, and anti-CD47 antibody to investigate the potential therapeutic role of AP. CD47 expression was negatively regulated by upstream miR133a, which is controlled by the transcription factor TRIM28. To further investigate the regulation of efferocytosis and reduction of pancreatic necrosis in AP, we used miR-133a-agomir and pancreas-specific AAV-shTRIM28 to modulate CD47 expression. Our findings confirmed that CD47-mediated efferocytosis is critical for preventing pancreatic necrosis and suggest that targeting the TRIM28-miR133a-CD47 axis is clinically relevant for the treatment of AP.
PubMed: 38872307
DOI: 10.1016/j.ymthe.2024.06.005 -
Pathology, Research and Practice Jun 2024Expression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed...
BACKGROUND
Expression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed description of the distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas.
METHODS
We collected healthy samples from cadavers (n = 4) and visceral surgery (n = 4) to investigate the respective expression profiles using immunohistochemical tracing with knockout-validated antibodies.
RESULTS
TRPC3- and TRPC6-proteins were detected in different pancreatic structures including acinar cells, as well as epithelial ductal cells from intercalate, intralobular, and interlobular ducts. Respective connective tissue layers appeared unstained. Endocrine islets of Langerhans were clearly and homogenously immunolabeled by the anti-TRPC3 and anti-TRPC6 antibodies. Insular α, β, γ, and δ cells were conclusively stained, although no secure differentiation of cell types was performed.
CONCLUSIONS
Due to aforementioned antibody specificity verification, protein expression in the immunolabeled localizations can be accepted. Our study in human tissue supports previous investigations especially with respect to acinar and insular α and β cells, while other localizations are here reported for the first time to express TRPC3 and TRPC6, ultimately warranting further research.
PubMed: 38870712
DOI: 10.1016/j.prp.2024.155403