Nasal NK/T-cell lymphoma (NKTCL) is an uncommon disease, but usually shows a highly aggressive clinical course. The disease is much more frequent in Asian and Latin American countries than in Western countries, and is universally associated with Epstein–Barr virus (EBV) infection. Analyses of gene mutations, especially p53 and c-KIT, revealed the different frequencies by district. Epidemiological studies revealed the changes of the disease frequency in Korea during the period from 1977–1989 to 1990–1996. Case-control study showed that the exposure to pesticides and chemical solvents could be causative of NKTCL. Further studies including HLA antigen typing of patients is necessary to further clarify the disease mechanism.

Extranodal CD56+ EBV- lymphoma at extranasal sites is a clinically less aggressive malignancy and displays less necrosis than CD56+ EBV+ lymphoma. Because CD56+ EBV+ TCR+ lymphomas show similar pathological and clinical findings to CD56+ EBV+ TCR- lymphomas, nasal-type NK/T-cell lymphomas at extranasal sites should be diagnosed as such on the basis of EBV+, cytotoxic T or NK phenotype irrespective of the genotype determined by molecular study.

Objective-Hypoxia-inducible factor 1␣ (HIF-1␣) is primarily involved in the adapting of cells to changes in oxygen levels, which is essential for normal vascular function. Recently, physiological roles for retinoic acid-related orphan receptor ␣ (ROR␣) have been implicated in cardiovascular diseases such as atherosclerosis. In this study, we have investigated the potential roles of ROR␣ in the hypoxia signaling pathway in connection with activation of HIF-1␣. Key Words: ROR␣ Ⅲ hypoxia Ⅲ HIF-1␣ Ⅲ melatonin Ⅲ vascular endothelial growth factor R etinoic acid receptor-related orphan receptor ␣ (ROR␣; NR1F1) is a member of the steroid/thyroid hormone receptor superfamily of transcriptional factors and is closely related to the retinoic acid receptors. 1,2 ROR␣ exists in 4 isoforms, ROR␣1, ROR␣2, ROR␣3, and ROR␣4 (also known as RZR␣), which are generated by a combination of alternative promoter use and exon splicing of the RORA gene. 2 These isoforms comprise a common DNA-binding domain (DBD) and a putative ligand-binding domain (LBD), but differ by their N-terminal sequences. 3 Melatonin and synthetic thiazolidine diones have been shown to transactivate ROR␣, although these observations need to be clarified. 4,5 Recently, analysis of the crystal structure of the ligand-binding domain of ROR␣ revealed that a ligand is present in the binding pocket. This was identified as cholesterol, suggesting that plasma and intracellular levels of cholesterol may be important in the regulation of transcriptional activity for ROR␣. 6,7 ROR␣ usually binds as a monomer to a ROR response element (RORE) consisting of a half site core AGGTCA motif or as a homodimer to a direct repeat of the core motif separated by 2 base pairs. 1 Putative ROREs have been identified in the promoters, such as human fibrinogen ␤, Apo A-V, Apo A-I, Apo C-III, PPAR␥, and RevErb␣, which may suggest a role of this receptor in lipid metabolism and cardiovascular physiology. 8 -12 However, little is known regarding the internal and external stimuli that regulate the RORA gene expression.ROR␣ functions have been studied with the help of the staggerer (sg/sg) mutant mouse. A spontaneous mutation in the ligand-binding domain induces a frameshift that results in a protein truncated in its C terminus and generates the staggerer phenotype. 13 These animals experience severe cerebellar ataxia caused by massive neurodegeneration of Purkinje cells. 14 Moreover, the phenotype of these mice revealed that ROR␣ is crucially involved in regulating the inflammatory and immune responses and lipid metabolism, which are closely related to vascular disorders such as atherosclerosis. 15,16 In the staggerer mice, angiogenesis is enhanced markedly after ischemia induced by the ligation of the femoral artery. 17 In the vascular system, ROR␣ mRNAs have been detected in human smooth muscle cells (SMCs), endothelial cells (ECs), as well as mammary arteries. 16,18 ROR␣ expression level is significantly decreased in human atherosclerotic plaques, whereas increased expression is observed a...

Cyclin dependent kinase 1 (Cdk1) have previously reported correlation with cancer growth and a key regulator for cell cycle. Mostly, Cdk1′s function of nucleus for cell cycle is well known to be associated with cancer, but cytoplasmic Cdk1′s traits are not clearly identified, yet. We revealed that tissue microarray blocks of epithelial ovarian cancer (n = 249) showed increased level of cytoplasmic Cdk1 (p < 0.001), but not in nucleus (p = 0.192) of histologic cell type independently. On survival analysis, Cdk1 overexpression conferred a significantly worse prognosis in 5-year overall survival (Log-rank p = 0.028, Hazard ratio = 2.016, 95% CI = 1.097 to 4.635). Also, the expression of Cdk1 was increased in ovarian cancer cell lines and Gene Expression Omnibus datasets. When the expression and activity of Cdk1 were inhibited by si-Cdk1 or RO-3306 which is a potent Cdk1 inhibitor, the growth of ovarian cancer was diminished. Moreover, combined treatment with RO-3306 and cisplatin in ovarian cancer significantly elevated anti-cancer effects than single-agent treatment. In conclusion, cytoplasmic Cdk1 expression which was elevated in ovarian cancer predicts a poor overall survival. The inhibition of Cdk1 expression and activity reduced ovarian cancer growth.

Three cases of extranodal marginal zone B-cell lymphoma (low grade B-cell lymphoma of mucosa-associated lymphoid tissue [MALT] type) in which the neoplastic B cells expressed the CD5 antigen are reported. The patients included 2 men and 1 woman, aged 44, 62, and 77 years. In all three cases, the histologic features were typical of marginal zone/MALT lymphoma, with reactive follicles, marginal zone (centrocyte-like) cells, and plasma cells. Pseudofollicles, prolymphocytes, and paraimmunoblasts were absent. In all cases, lymphoma from one or more sites expressed monotypic immunoglobulin (2 IgM kappa, 1 IgM lambda), pan B cell antigens and CD5. Two of 3 cases expressed CD43; one case expressed CD23. No case showed overexpression of the bcl-1 protein, cyclin D1. Interphase cytogenetic analysis revealed trisomy 3 in one of two cases examined. The two male patients presented with lymphoma in the ocular adnexa. One of them had marrow involvement, cervical lymphadenopathy and peripheral blood involvement at presentation; 24 months later, he developed a relapse in subcutaneous tissue. The second patient had marrow involvement 3 years later, at the time of recurrence of his orbital disease. The third patient presented with lymphoma at the base of the tongue. She subsequently developed lymphoma involving the left upper eyelid and right lacrimal sac and duct, the marrow, and the nasopharynx between 63 and 95 months after initial presentation. All of these patients presented with disease involving sites in the head and neck and all had multiple relapses or recurrences with bone marrow involvement at the time of presentation (1 case) or at relapse (2 cases). The presence of CD5 may be a marker for cases of MALT lymphoma with a tendency for persistent or recurrent disease, for dissemination to the marrow and other extranodal sites, and for leukemic involvement of the peripheral blood.

No abstract

Cyclin D1/PRAD1 (bcl-1) is a recently discovered proto-oncogene that is overexpressed in mantle cell lymphomas and several other human tumors. In a previous study, the authors demonstrated expression of cyclin D1 in 15 of 15 cases of mantle cell lymphoma and 1 of 8 cases of B-chronic lymphocytic leukemia (B-CLL) using a polyclonal antibody and microwave enhanced immunohistochemical staining method on paraffin-embedded tissue sections. In this study, 107 additional B- and T-cell neoplasms were studied, including 47 cases of high grade lymphoma (33 diffuse large B-cell type, 9 Burkitt and Burkitt-like, 4 precursor T-lymphoblastic lymphoma, and 1 adult T-cell lymphoma/leukemia), 38 additional cases of low grade B-cell lymphoma (18 CLL, 15 hairy cell leukemia and 5 mantle cell lymphoma), and 22 plasmacytomas for expression of cyclin D1 using the same immunohistochemical staining technique. All cases of mantle cell lymphoma showed diffuse nuclear staining. No additional cases of CLL showed cyclin D1 expression. In contrast, 1 of 15 hairy cell leukemias and 1 of 22 plasmacytomas showed cyclin D1 staining. None of the high grade lymphomas demonstrated expression of cyclin D1 protein by immunostaining, including three cases of large B-cell lymphoma that coexpressed CD5. The authors conclude that cyclin D1 is expressed in all cases of mantle cell lymphoma, and only in very rare cases of B-CLL, hairy cell leukemia and plasmacytoma/myeloma. Cyclin D1 does not appear to play an important role in high grade lymphomas. In addition, most CD5 positive high grade B-cell lymphomas do not express cyclin D1, and are not likely to be derived from mantle cell lymphoma or other lymphomas with t(11;14).

BCL1/PRAD1 gene rearrangements involving the cyclin D1 gene are a feature of about 70% of centrocytic/mantle-cell lymphomas (CC/MCL) but are identified in only a small proportion of other B-cell non-Hodgkin's lymphomas. Of 37 lymphomas found to have BCL1/cyclin D1 (PRAD1, CCND1) gene rearrangements, 30 fit the morphologic and immunophenotypic criteria for typical CC/MCL. Seven cases with morphologic features atypical for CC/MCL were identified. CD5+ monoclonal B cells were documented in all these cases. Six cases were subsequently stained for cyclin D1 protein, and all showed nuclear positivity. Five cases had variably sized foci of cells with moderately abundant pale cytoplasm resembling parafollicular/monocytoid B cells, marginal zone cells, hairy cells, or even proliferation centers. Transformed-appearing cells were also present in some lymphomas. In one case, striking follicular colonization created a markedly nodular growth pattern mimicking a follicular lymphoma. A sixth case had a marked predominance of small, round lymphocytes at some sites, mimicking a small lymphocytic lymphoma. Five of these six cases also had areas more typical of CC/MCL. The seventh case was a CD5-positive splenic marginal zone-like lymphoma (SMZL) with plasmacytic differentiation and circulating villous lymphocytes consistent with a splenic lymphoma with villous lymphocytes (SLVL). These cases illustrate the morphologic spectrum of small B-cell lymphoid neoplasms that have BCL1/cyclin D1 gene rearrangements and overexpression of cyclin D1. Despite the BCL1 translocation and cyclin D1 overexpression, the splenic lymphoma with plasmacytic differentiation was definitely not a CC/MCL and fit the clinicopathologic entity of SMZL/SLVL. The other six cases are best considered CC/MCL variants based on a combined morphologic, immunophenotypic, and genotypic evaluation. Genotypic or immunophenotypic studies to identify cyclin D1 rearrangements and overexpression, although not pathognomonic, are useful in recognizing these variant CC/MCL cases, which can mimic almost any of the other well-described but more indolent low-grade B-cell lymphomas and leukemias. Some of the variant CC/MCL cases had features in common with the CD5+ cyclin D1+ SMZL/SLVL, suggesting a possible relationship between these two otherwise distinct entities.