Apolipoprotein A-I (ApoA-I), the major protein component of high-density lipoproteins (HDL) is a multifunctional protein, involved in cholesterol traffic and inflammatory and immune response regulation. Many studies revealing alterations of ApoA-I during the development and progression of various types of cancer suggest that serum ApoA-I levels may represent a useful biomarker contributing to better estimation of cancer risk, early cancer diagnosis, follow up, and prognosis stratification of cancer patients. In addition, recent in vitro and animal studies disclose a more direct, tumor suppressive role of ApoA-I in cancer pathogenesis, which involves anti-inflammatory and immune-modulatory mechanisms. Herein, we review recent epidemiologic, clinicopathologic, and mechanistic studies investigating the role of ApoA-I in cancer biology, which suggest that enhancing the tumor suppressive activity of ApoA-I may contribute to better cancer prevention and treatment.
8 April 2019 in Archives of Pathology & Laboratory Medicine
Anastomosing hemangioma is a rare neoplastic vascular lesion, histologically mimicking angiosarcoma. It is predominantly composed of irregularly anastomosing sinusoidal-like spaces lined by endothelial cells with minimal atypia, a frequently hobnail morphology, and minimally invasive margins. Since its original description in the genitourinary system, an increasing number of anastomosing hemangiomas have been reported, localized deep in the body in various organs, always with similar histologic features. It is more frequently asymptomatic, often discovered incidentally by imaging studies, owing to coexisting benign or malignant tumors. In renal cases, the most frequent clinical context is end-stage renal disease. There is overwhelming evidence of the benign nature of the lesion and an accurate diagnosis could prevent overtreatment. The differential diagnosis includes other benign vascular tumors, well-differentiated angiosarcoma, Kaposi sarcoma, and other vascular-rich neoplasms. We review the clinical and histopathologic characteristics of this peculiar lesion with an emphasis on the differential diagnosis.
Anastomosing hemangioma (AH) is a very rare vascular tumor mimicking angiosarcoma, predominately observed in kidney and less frequently in other organs. We present two new renal cases of AH at opposite ends of the clinical presentation spectrum, provide review of the literature and compare the epidemiological, clinical and pathological profiles of renal and non-renal cases. The first occurred in a 64-year-old woman presented with back pain and the second, a multifocal lesion, in a 47-year-old man with end stage renal disease (ESRD). Histology disclosed a vascular tumor with striking anastomosing pattern, minimal nuclear atypia and locally infiltrative pattern, mimicking superficially angiosarcoma. Extramedullary hematopoiesis, extensive perirenal fat entrapment and increased number of mast cells were additional features in the second lesion. Both patients are well, without disease, 25 and 14 months after diagnosis. Comprehensive review and analysis of the published literature show that the growing number of non-renal AHs exhibits similar epidemiologic, clinical, biologic and histologic characteristics with renal AHs and most mild differences vanish after exclusion of cases associated with ESRD. Better understanding of AH pathogenesis will contribute to optimal treatment choices.
The ROR1 receptor tyrosine kinase is expressed in embryonic tissues but is absent in normal adult tissues. ROR1 is of importance in oncogenesis and is overexpressed in several cancers, such as NSCLC. In this study, we evaluated ROR1 expression in NSCLC patients (N = 287) and the cytotoxic effects of a small molecule ROR1 inhibitor (KAN0441571C) in NSCLC cell lines. ROR1 expression in tumor cells was more frequent in non-squamous (87%) than in squamous (57%) carcinomas patients, while 21% of neuroendocrine tumors expressed ROR1 (p = 0.0001). A significantly higher proportion of p53 negative patients in the ROR1+ group than in the p53 positive non-squamous NSCLC patients (p = 0.03) was noted. KAN0441571C dephosphorylated ROR1 and induced apoptosis (Annexin V/PI) in a time- and dose-dependent manner in five ROR1+ NSCLC cell lines and was superior compared to erlotinib (EGFR inhibitor). Apoptosis was confirmed by the downregulation of MCL-1 and BCL-2, as well as PARP and caspase 3 cleavage. The non-canonical Wnt pathway was involved. The combination of KAN0441571C and erlotinib showed a synergistic apoptotic effect. KAN0441571C also inhibited proliferative (cell cycle analyses, colony formation assay) and migratory (scratch wound healing assay) functions. Targeting NSCLC cells by a combination of ROR1 and EGFR inhibitors may represent a novel promising approach for the treatment of NSCLC patients.
We hypothesized that murine double minute X (MDMX), a negative p53-regulator, may be involved in dysfunctional p53-signaling in anaplastic large cell lymphoma (ALCL), anaplastic lymphoma kinase (ALK)-positive and ALK-negative, characterized frequently by non-mutated TP53 (wt-p53). By western blot analysis, MDMX was highly expressed in ALK + ALCL and expressed at variable levels in ALK- ALCL cell lines. By immunohistochemistry, high MDMX levels were observed more frequently in ALK + ALCL (36/46; 78%), compared with ALK- ALCL tumors (12/29; 41%) (p < .0018, Mann–Whitney-test). FISH analysis showed MDMX-amplification in 1 of 13 (8%) ALK- ALCL tumors, and low-level MDMX copy gains in 2 of 13 (15%) ALK- ALCL and 3 of 11 (27%) ALK + ALCL tumors. MDMX-pharmacologic inhibition or siRNA-mediated MDMX-silencing were associated with activated p53 signaling, growth inhibition and apoptotic cell death in wt-p53 ALCL cells, providing evidence that targeting MDMX may provide a new therapeutic approach for ALCL patients with wt-p53.
The oncogenic pathways activated by the NPM-ALK chimeric kinase of ALK+ anaplastic large cell lymphoma (ALCL) are well characterized; however, the potential interactions of ALK signaling with the microenvironment are not yet known. Here we report that ALK+ ALCL-derived exosomes contain critical components of ALK signaling as well as CD30, and that exosome uptake by lymphoid cells led to increased proliferation and expression of critical antiapoptotic proteins by the recipient cells. The bone marrow fibroblasts highly uptake ALK+ ALCL-derived exosomes and acquire a cancer-associated fibroblast (CAF) phenotype. Moreover, exosome-mediated activation of stromal cells altered the cytokine profile of the microenvironment. These interactions may contribute to tumor aggressiveness and possibly resistance to treatment.