Search

Mutations in the JAK2, CALR, and MPL genes have been shown to have prognostic value in essential thrombocythaemia (ET), but no clear association with morphological changes has been reported so far. We investigated the possible correlation between gene mutations and histopathological features in bone marrow (BM) biopsies of patients with ET.Marrow cellularity, fibrosis, and the number of total and dysmorphic megakaryocytes and clusters of megakaryocytes were compared to gene mutations in 90 cases of ET at diagnosis.The JAK2V617F mutation was found in 58.9%, CALR in 28.9%, and MPL in 4.4% of the cases, and 7.8% were triple-negative. JAK2V617F-mutated ET showed a high BM cellularity, the lowest number of clusters of megakaryocytes and the highest number of dysmorphic megakaryocytes; CALR-mutated ET showed a reduced BM cellularity, many clusters of large megakaryocytes, and very few dysmorphic megakaryocytes; MPL-mutated ET showed the lowest BM cellularity, the highest number of clustered and large megakaryocytes, and the lowest number of dysmorphic megakaryocytes. Triple-negative ET cases had the highest BM cellularity.Distinct morphological patterns were associated with gene mutations in ET, supporting the classification of ET into different subtypes.

Supplemental Digital Content is available in the text., The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2013 guidelines for HER2 assessment have increased the number of HER2 equivocal breast carcinomas following in situ hybridization reflex testing, that is, HER2 “double equivocal” (equivocal protein expression and equivocal gene copy number). Forty-five double-equivocal carcinomas were subjected to Prosigna analysis. Twenty-seven cases were investigated for the expression of genes found to be differentially expressed between estrogen receptor (ER)-positive/HER2-positive (N=22) and ER-positive/HER2-negative (N=22) control cases. Twenty-nine of the 45 cases were also analyzed by targeted sequencing using a panel of 14 genes. We then explored the pathologic complete response rates in an independent series of double-equivocal carcinoma patients treated with trastuzumab-containing chemotherapy. All cases were ER-positive, with a mean Ki67 of 28%. Double-equivocal carcinomas were predominantly luminal B (76%); 9 cases (20%) were luminal A, and 2 cases (4%) HER2-enriched. The majority (73%) showed a high risk of recurrence by Prosigna, even when the carcinomas were small (

Objectives Tumor angiogenesis is an essential and complex process necessary for the growth of all tumors which represents a potential therapeutic target. Angiogenesis inhibitors targeting vascular endothelial growth factor (VEGF) or their receptor tyrosine kinases have been approved by the FDA. In thymic epithelial tumors (TET), targeted therapies have been sporadically applied due to their rarity. To ascertain the presence of potential therapeutic targets, we analyzed by immunohistochemistry the expression of angiogenesis-related biomarkers in a large series of TET arranged in Tissue Micro Arrays (TMA). Materials and methods We assessed by immunohistochemistry the expression of the possible molecular target of anti-angiogenic therapy, i.e. VEGFA, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, and PDGFRβ, in a TMA series of 200 TET collected in the framework of a multi-institutional collaborative project for Rare Diseases. Results When compared to the low-risk tumors, high-risk TET (B2, B3, carcinomas) contained higher proportion of cancer cells expressing VEGFA, VEGFC and VEGFD ( P P P P =0.002), VEGFR2 ( P =0.013), and VEGFR3 ( P =0.041). No differences were observed in terms of PDGFRβ expression. Conclusions According to our data, it is possible to hypothesize the existence of multiple paracrine and/or autocrine loops in TET, particularly in the high-risk ones, involved in TET growth and progression. Anti-angiogenic agents, directed to inhibit these loops, are therefore to be considered as potential tools in advanced TET therapy.

Anaplastic large cell lymphomas (ALCLs) frequently carry oncogenic fusions involving the anaplastic lymphoma kinase (ALK) gene. Targeting ALK using tyrosine kinase inhibitors (TKIs) is a therapeutic option in cases relapsed after chemotherapy, but TKI resistance may develop. By applying genomic loss-of-function screens, we identified PTPN1 and PTPN2 phosphatases as consistent top hits driving resistance to ALK TKIs in ALK+ ALCL. Loss of either PTPN1 or PTPN2 induced resistance to ALK TKIs in vitro and in vivo. Mechanistically, we demonstrated that PTPN1 and PTPN2 are phosphatases that bind to and regulate ALK phosphorylation and activity. In turn, oncogenic ALK and STAT3 repress PTPN1 transcription. We found that PTPN1 is also a phosphatase for SHP2, a key mediator of oncogenic ALK signaling. Downstream signaling analysis showed that deletion of PTPN1 or PTPN2 induces resistance to crizotinib by hyperactivating SHP2, the MAPK, and JAK/STAT pathways. RNA sequencing of patient samples that developed resistance to ALK TKIs showed downregulation of PTPN1 and PTPN2 associated with upregulation of SHP2 expression. Combination of crizotinib with a SHP2 inhibitor synergistically inhibited the growth of wild-type or PTPN1/PTPN2 knock-out ALCL, where it reverted TKI resistance. Thus, we identified PTPN1 and PTPN2 as ALK phosphatases that control sensitivity to ALK TKIs in ALCL and demonstrated that a combined blockade of SHP2 potentiates the efficacy of ALK inhibition in TKI-sensitive and -resistant ALK+ ALCL.