Lysine methyltransferase 2D regulates pancreatic carcinogenesis through metabolic reprogramming

Objective: Despite advances in the identification of epigenetic alterations in pancreatic cancer, their biological roles in the pathobiology of this dismal neoplasm remain elusive. Here, we aimed to characterise the functional significance of histone lysine methyltransferases (KMTs) and demethylases (KDMs) in pancreatic tumourigenesis. Design: DNA methylation sequencing and gene expression microarrays were employed to investigate CpG methylation and expression patterns of KMTs and KDMs in pancreatic cancer tissues versus normal tissues. Gene expression was assessed in five cohorts of patients by reverse transcription quantitative-PCR. Molecular analysis and functional assays were conducted in genetically modified cell lines. Cellular metabolic rates were measured using an XF24-3 Analyzer, while quantitative evaluation of lipids was performed by liquid chromatography-mass spectrometry (LC-MS) analysis. Subcutaneous xenograft mouse models were used to evaluate pancreatic tumour growth in vivo. Results: We define a new antitumorous function of the histone lysine (K)-specific methyltransferase 2D (KMT2D) in pancreatic cancer. KMT2D is transcriptionally repressed in human pancreatic tumours through DNA methylation. Clinically, lower levels of this methyltransferase associate with poor prognosis and significant weight alterations. RNAi-based genetic inactivation of KMT2D promotes tumour growth and results in loss of H3K4me3 mark. In addition, KMT2D inhibition increases aerobic glycolysis and alters the lipidomic profiles of pancreatic cancer cells. Further analysis of this phenomenon identified the glucose transporter SLC2A3 as a mediator of KMT2D-induced changes in cellular, metabolic and proliferative rates. Conclusion: Together our findings define a new tumour suppressor function of KMT2D through the regulation of glucose/fatty acid metabolism in pancreatic cancer

Cirrhotic livers reveal genetic changes in the MDM2-P14ARF system of cell cycle regulators

The genesis of hepatocellular carcinoma is promoted by changes in the regulatory MDM2-P14ARF system. The incidence of such changes has to date not been analysed in non-tumourous livers showing regenerative proliferation. In the present study, 24 cirrhotic livers of alcohol-, autoimmue disorder- or HCV-caused genesis were screened for MDM2-P14ARF alterations at the level of protein, DNA and mRNA. Using confocal laser scanning microscopy, the absence of MDM2 and P14ARF expression was detected in all samples except three HCV-infected livers (four livers) which contained hepatocytes overexpressing MDM2 (P14ARF) protein. In two of the samples lacking P14ARF expression, laser microdissection and PCR demonstrated deletion of the P14ARF gene. The P14ARF gene amplified from other specimens did not carry mutations. MDM2 splicing variants were present in tissues from alcohol- and autoimmune disorder-induced cirrhoses. Sequencing of full-size mRNA revealed a MDM2 mis-sense mutation in an alcohol-induced cirrhosis. One sample contained regenerative nodules with genetic instability occurring at MDM2 locus D12S83 according to the data of automatic PCR fragment analysis. In summary, this study gives first evidence for different types of MDM2 and P14ARF alterations in cirrhotic livers. We suggest that the changes impair the regulatory MDM2-P14ARF system, thus possibly favouring regenerative proliferation and transformation

Osteolytic lesions (brown tumors) of primary hyperparathyroidism misdiagnosed as multifocal giant cell tumor of the distal ulna and radius: a case report

Abstract Background Brown tumors represent a rare clinical manifestation reported in approximately 3% of patients with primary hyperparathyroidism and correspond to radiologically osteolytic lesions with well-defined borders in different parts of the skeleton. Case presentation We report the case of a 53-year-old white man who presented to our hospital with osteolytic lesions of his distal ulna and radius, causing pain and swelling of 2-month duration. A subsequent biopsy revealed histological features consistent with giant cell tumor and a complete resection of his distal ulna was followed, along with curettage and cementoplasty of the distal radial metaphysis. Two weeks later, he was re-admitted with diffuse musculoskeletal soreness, anorexia, constipation, nausea, and localized abdominal pain and multiple osteolytic lesions on plain radiographs. A histopathological examination of the ulna and radius specimens showed similar findings and, given the multifocality, brown tumors related to primary or secondary hyperparathyroidism was included in the differential diagnosis. A laboratory examination showed high total serum calcium (14.5 mg/dl) and low serum phosphorus and 25-hydroxyvitamin D levels. Primary hyperparathyroidism was suspected and confirmed by the elevated parathyroid hormone levels of 1453 pg/mL. At radiological work-up, using computed tomography, ultrasonography, and parathyroid subtraction technetium-99m sestamibi scintigraphy, a 4.5 × 2.5 × 3.2 cm mass emanating from the right lobe of his thyroid gland was detected, displaying extensive uptake in the right lower parathyroid gland. After appropriate medical support including hyperhydration and high doses of diuretics and diphosphonates, his laboratory profile normalized and he underwent total thyroidectomy with removal of the parathyroid glands. Our patient is now recovering 12 months after surgery, with normal values of serum parathyroid hormone and calcium levels. The lytic bone lesions have almost disappeared and no other additional orthopedic intervention was necessary. Conclusions The present case report emphasizes the need of inclusion of brown tumors in the differential diagnosis of multifocal osteolytic bone lesions, in order to avoid harmful surgical interventions. Laboratory testing of serum phosphate, calcium levels, and parathyroid hormone levels should always be included in the routine survey of patients with multifocal osteolytic lesions

Paclitaxel and carboplatin as first-line chemotherapy combined with gefitinib (IRESSA) in patients with advanced breast cancer: a phase I/II study conducted by the Hellenic Cooperative Oncology Group

Paclitaxel (lTaxol(R)) and carboplatin are an effective combination regimen for treating advanced breast cancer. Gefitinib (IRESSA) is the first epidermal growth factor receptor tyrosine kinase inhibitor to be approved for cancer treatment. This multicenter phase II trial treated 68 patients with advanced breast cancer with paclitaxel ( 175 mg/ m 2 over 3 h) and 3-weekly carboplatin ( area under the curve of 6) for six cycles, and 250 mg/ day gefitinib orally. Median age was 57 ( range 35 - 77) years, patients had performance status 0 (69.1%), 1 (27.9%) 2 (2.9%), 82.4% of patients had visceral metastases and 63.2% had received adjuvant chemotherapy. Forty-eight (70.6%) patients completed six cycles of chemotherapy and 20 (29.4%) patients discontinued treatment ( seven [10.3%] due to disease progression, seven [ 10.3%] due to toxicity,five [7.4%] withdrew consent and one [1.5%] died after the first cycle). Sixty-three (92.7%) patients were evaluable for response; nine (13.2%) had complete responses, 30 (44.1%) had partial responses, 21 (30.9%) had stable disease and three (4.4%) had disease progression. Grade 3/4 adverse events in >= 5% of patients except of alopecia, included neutropenia (17.7%), anemia ( 10.3%), diarrhea ( 7.4%), thrombocytopenia (5.9%) and peripheral neuropathy ( 5.9%). Of those tumor biopsies available for immunohistochemical analysis ( n= 60), 5.0% were positive and 35.0% negative for expression of all HER-family receptors. Comparable numbers of tumor biopsies were nuclear p27(kipl) positive and negative (39.7 and 42.7%, respectively), with the majority (72.1%) negative for cytoplasmic p27(kipl). The observed efficacy data in this study were similar to those reported for the combination of paclitaxel and carboplatin alone

Differential expression of the insulin-like growth factor receptor among early breast cancer subtypes

Introduction: We sought to determine the level of protein expression of the critical components of the insulin-like growth factor receptor (IGFR) pathway and to evaluate their prognostic significance across the different early breast cancer subtypes. Patients and Methods: Archival tumor tissue from 1,021 women with early, node positive breast cancer, who were prospectively evaluated within two randomized clinical trials, was used to construct tissue microarrays that were stained for hormone receptors (HR), Ki67, HER2, epidermal growth factor receptor (EGFR) and cytokeratins 5/6, to classify tumors into five immunophenotypical subgroups. Immunohistochemical (IHC) expression of IGF1R-alpha and beta subunits, IGF2R and IGF-binding protein 2 (IGFBP2) was assessed using the immunoreactive score (IRS). Repeated internal cross-validation was performed to examine the statistical validity of the cut off points for all biomarkers. Results: After a median follow-up time of 105.4 months, overall 370 women (36.2%) had relapsed and 270 (26.4%) had died. Tumors expressing IGF1R-alpha above the median IRS were significantly more frequently HR positive (luminal A+B+HER2), as compared to HER2-enriched and triple negative ones (p<0.001 for both comparisons). IGF2R was overexpressed significantly more frequently in HR negative tumors (p = 0.001) and had an inverse correlation with all other biomarkers. Patients with luminal A and B tumors with high IGF1R-alpha and negative EGFR expression (N = 190) had significantly higher 4-year survival rates, as compared to the rest (log-rank p = 0.046), as did patients with luminal A and B tumors with high IGF1R-alpha and low IGF2R expression, as compared to the rest (N = 91), (log-rank p = 0.035). After adjustment for significant variables, patients in the latter group had a relative 45% reduction in the risk of death, as compared to the rest (p = 0.035). Conclusion: Aberrant expression of components of the IGF1R pathway is associated with better clinical outcomes in women with luminal A and B, node positive, early breast cancer. Copyright: © 2014 Mountzios et al