Caspase-3 activation in systemic anaplastic large-cell lymphoma.

Anaplastic large-cell lymphoma (ALCL), as currently defined, includes a subset of tumors that have abnormalities of chromosome 2p23 (alk gene) resulting in overexpression of anaplastic lymphoma kinase (ALK). We have previously shown differences in apoptotic rate and expression of apoptosis-related proteins between ALK-positive and ALK-negative ALCL. In this study, we assessed for activated caspase-3 (aC-3), an executioner of apoptotic cell death, in ALCL cell lines and tumors. We used the Karpas 299 and SU-DHL-1 cell lines, and the caspase inhibitors Boc-D-FMK and DEVD-FMK to investigate the role of caspase-3 activation in tumor cell death after treatment with doxorubicin. Cell viability and apoptosis were assessed by trypan blue and Annexin-V methods. A caspase-3 assay was used to evaluate caspase-3 enzymatic activity. Caspase-3 activity was significantly increased in Karpas-299 and SU-DHL-1 cells treated with doxorubicin, but remained as low as control levels with addition of Boc-D-FMK or DEVD-FMK. Expression of aC-3 was also assessed immunohistochemically in 57 ALCL tumors. The mean percentage of aC-3 positive tumor cells was 3.2% in ALK-positive ALCL compared with 1.2% in ALK-negative ALCL (P=0.0003, Mann-Whitney test), and inversely correlated with BCL-2 expression (P=0.01, Mann-Whitney test). aC-3 expression did not correlate with patient outcome in either the ALK-positive or ALK-negative ALCL groups. In conclusion, doxorubicin-induced cell death of ALK-positive ALCL cells involves caspase-3 activation in vitro. aC-3 levels correlate with ALK expression in ALCL tumors.     

Genomic profiling of peripheral T-cell lymphoma, unspecified, and anaplastic large T-cell lymphoma delineates novel recurrent chromosomal alterations

To characterize genetic alterations in peripheral T-cell lymphoma, not otherwise specified (PTCL NOS), and anaplastic large T-cell lymphoma (ALCL), 42 PTCL NOS and 37 ALCL [17 anaplastic large cell kinase (ALK)-negative ALCL, 9 ALK-positive ALCL, 11 cutaneous ALCL] were analyzed by comparative genomic hybridization. Among 36 de novo PTCL NOS, recurrent chromosomal losses were found on chromosomes 13q (minimally overlapping region 13q21, 36% of cases), 6q and 9p (6q21 and 9p21-pter, in 31% of cases each), 10q and 12q (10q23-24 and 12q21-q22, in 28% of cases each), and 5q (5q21, 25% of cases). Recurrent gains were found on chromosome 7q22-qter (31% of cases). In 11 PTCL NOS, high-level amplifications were observed, among them 3 cases with amplification of 12p13 that was restricted to cytotoxic PTCL NOS. Whereas cutaneous ALCL and ALK-positive ALCL showed few recurrent chromosomal imbalances, ALK-negative ALCL displayed recurrent chromosomal gains of 1q (1q41-qter, 46%), and losses of 6q (6q21, 31%) and 13q (13q21-q22, 23%). Losses of chromosomes 5q, 10q, and 12q characterized a group of noncytotoxic nodal CD5+ peripheral T-cell lymphomas. The genetics of PTCL NOS and ALK-negative ALCL differ from other T-NHLs characterized genetically so far, among them enteropathy-type T-cell lymphoma, T-cell prolymphocytic leukemia, and adult T-cell lymphoma/leukemia.     

Apoptotic rate in peripheral T-cell lymphomas. A study using a tissue microarray with validation on full tissue sections

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of non-Hodgkin lymphomas with a wide spectrum of clinicopathologic features, and apoptosis mechanisms may have a role in lymphomagenesis. We assessed apoptotic rate (AR) in 112 PTCLs using a tissue microarray developed in our laboratory and a modified terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The mean AR was 1.47% +/- 1.38% for the entire group of PTCLs (range, 0.06%-5.15%), and AR varied significantly among different tumor types. In mycosis fungoides, the mean AR was 0.74%; angioimmunoblastic T-cell lymphoma, 1.02%; PTCL, not otherwise specified, 1.38%; cutaneous anaplastic large cell lymphoma (ALCL), 1.41%; anaplastic lymphoma kinase protein (ALK)-negative ALCL, 1.43%; extranodal natural killer/T-cell lymphoma of nasal type, 2.04%; ALK-positive ALCL, 2.95%; and enteropathy-type T-cell lymphoma, 3.06%. Mean AR was higher in PTCL with large cell vs small/medium cell morphologic features (1.66% +/- 1.1% vs 0.99% +/- 1.0%). In a subset of 33 PTCLs, the tissue microarray results comparedfavorably with those obtained in full tissue sections. We conclude that the highest ARs in PTCLs are found in enteropathy-type T-cell lymphoma and ALK-positive ALCL, and that AR can be assessed reliably by using a tissue microarray.     

间变性淋巴瘤激酶阳性和阴性系统性间变性大细胞淋巴瘤临床病理特征对比研究

目的 探讨间变性淋巴瘤激酶(ALK)阳性和阴性原发性系统性间变性大细胞淋巴瘤(ALCL)与临床病理学特征、免疫表型及分子遗传学之间的差异.方法 收集北京友谊医院病理科2003年lO月至2008年10月活检及会诊中83例ALCL.最后确诊为原发性系统性ALCL 74例,其中有8例未做ALK检测.通过分析临床资料、观察组织形态,采用免疫组织化学EliVision法检测肿瘤细胞表达CD30、ALK、上皮细胞膜抗原(EMA)、CD2、CD3、颗粒酶B/T细胞内抗原(TIA)-1的情况,采用原位杂交的方法检测EB病毒小mRNA,荧光原位杂交(FISH)方法检测染色体是否存在异常.结果 ALK~+ALCL 48例,ALK-ALCL 18例.ALK~+ALCL发病年龄明显较ALK~-ALCL年轻,中位年龄分别为18和36岁,差异有统计学意义(P＜0.05).ALK~+ALCL比ALK~-ALCL患者更多伴有发热症状(33∶4),常常是高热,并且总体存活率(80%∶71%)和中位生存时间(21个月∶12.5个月)更长,但差异均无统计学意义(P＞0.05).ALK~+ALCL更多原发于结内(81%∶56%).ALK~+ALCL和ALK~-ALCL在形态学上差异不明显,多数病例呈弥漫生长,少数表现为结节状生长;66例ALCL中均可以见到标志性细胞,8例有灶状坏死,偶见黏液基质.ALK~+ALCL主要亚型是普通型(35例),其次是淋巴组织细胞型(8例),小淋巴细胞型(3例)和肉瘤型(2例)少见;ALK~-ALCL绝大多数是普通型(17例),仅1例是淋巴组织细胞型.ALK~+ALCL总是同时表达ALK、CD30和EMA;ALK~+ALCL的EMA表达率更高(100%:72%,P＜0.05),ALK~+ALCL的T细胞标记(如CD2/CD3、CD43/CD45RO)的表达率较低,细胞毒性分子表达率较高(P＞0.05).ALCL未检测到EB病毒感染.FISH结果显示4例ALK~+ALCL中1例ALK基因正常,1例基因断裂伴多拷贝,2例仅有断裂;1例ALK~+ALCL中ALK基因正常.结论 ALK~+ALCL与ALK~-ALCL在形态学上没有显著性差异,但在临床特征和免疫表型和分子遗传学特点方面存在一定差异,这些有助于二者的鉴别诊断.     

Overexpression of BCL-2, BCL-X, and BAX in primary central nervous system lymphomas that occur in immunosuppressed patients.

In contrast to primary central nervous system lymphomas (PCNSLs) that occur in immunocompetent patients, most of those that occur in immunosuppressed patients are associated with Epstein-Barr virus (EBV). BCL-2-related proteins either block or promote cell death, forming homo- or heterodimers with each other. LMP-1, EBV latent protein, has been shown to upregulate BCL-2 and BCL-XL. This observation suggests that these proteins may be involved in the transformation process of EBV-infected cells. Twenty-three cases of PCNSLs were studied: 12 of the patients were immunosuppressed, and 11 were immunocompetent. For all cases, we collected clinical information, histologic data, and immunophenotype and tested for the presence of EBV (EBER-1, LMP-1). Apoptosis was assessed by the TdT-mediated dUTP-biotin nick-end labeling method and quantified by image analysis. In three cases, electron microscopy was performed. The BCL-2 family proteins (BCL-2, BCL-X, MCL1, and BAX) and p53 expression were studied by immunohistochemistry on paraffin slides. All cases were classified as diffuse large B-cell lymphomas. PCNSLs in immunosuppressed patients were characterized by EBV association, necrosis, important gliosis, and numerous macrophages. There was no significant difference between the two groups regarding the TdT-mediated dUTP-biotin nick-end labeling staining (P = .08). In contrast, PCNSLs in immunosuppressed patients were shown to express high levels of BCL-2, BCL-X, and BAX in more than 80% of tumor cells in 7, 10, and 11 cases, respectively. In immunocompetent patients, only one case showed a high level of BCL-2 expression in more than 80% of the cells, whereas BCL-X and BAX were overexpressed in two cases. These differences are significant (P < .05). In contrast, there was no significant difference between the two groups in MCL-1 expression. Besides EBV association and necrosis, PCNSLs related to immunosuppression are characterized by an overexpression of BCL-2-related proteins, without dramatically modifying their susceptibility for apoptosis.     

Differential expression of thymus and activation regulated chemokine and its receptor CCR4 in nodal and cutaneous anaplastic large-cell lymphomas and Hodgkin's disease.

Recent studies demonstrated that Hodgkin/Reed-Sternberg (H/RS) cells in Hodgkin's disease (HD) express thymus and activation-regulated chemokine (TARC), whereas reactive lymphocytes surrounding H/RS cells express its ligand, CC-chemokine receptor 4 (CCR4). Because in vitro studies showed that CCR4 expression is a marker for lymphocytes bearing a T-helper 2 (Th2) phenotype, it was suggested that expression of TARC is a new immune escape mechanism in HD. To find out whether this mechanism might also be operative in CD30+ malignant lymphomas other than HD, TARC and CCR4 expression was investigated by immunohistochemistry on paraffin and frozen-tissue sections of 39 nodal CD30+ anaplastic large cell lymphomas (ALCL), including 27 ALK-negative and 12 ALK-positive ALCL, 25 primary cutaneous CD30+ ALCL, including 11 patients with lymphomatoid papulosis, and 31 cases of HD. TARC was expressed by the neoplastic cells in 12/27 (44%) nodal ALK-negative ALCL and all cases of classic HD, but not in nodal ALK-positive ALCL (0/12) and only rarely in primary cutaneous CD30+ ALCL (3/25). In contrast, CCR4 was expressed by the neoplastic cells in 9/9 cutaneous CD30+ ALCL, and in 9/15 (60%) nodal ALK-negative ALCL, but only in 1/4 (25%) nodal ALK-positive ALCL and not by the H/RS cells in HD (0/8). Apart from three cases of HD showing 10 to 15% CCR4-positive lymphocytes surrounding TARC-positive H/RS cells, CCR4-positive reactive T cells were few (<5%) in all other cases studied. Our results demonstrate a differential expression of TARC and CCR4 in different types of CD30+ malignant lymphomas. The small number of CCR4-positive reactive T cells in most cases studied argues against an important role of TARC expression in the evasion of antitumor responses.     

Apoptosis-associated gene expression in HIV-infected patients in response to successful antiretroviral therapy

The simultaneous expression of 19 apoptosis-related genes was analyzed by RNA-protection assay in peripheral blood mononuclear cells of HIV-infected patients before and during successful antiretroviral therapy (ART). After 12 months of therapy, the expression of the pro-apoptotic genes FAS, FAS-L, FAF-1, FADD, CASPASE-8, DR3, TRAIL, TNFR-1, TRADD, and BAX was significantly downregulated with respect to time 0, while that of BCL-2, BCL-XL, and MCL-1 was significantly upregulated. The data suggest that inhibition of cell death in HIV-positive patients under successful therapy is the result of a complex network of multifactor signaling, correlated with both death and survival of lymphocytes.     

ALK-negative anaplastic large-cell lymphoma demonstrates similar poor prognosis to peripheral T-cell lymphoma, unspecified

AIMS: Anaplastic large cell lymphoma (ALCL) is classically considered a clinicopathological entity separate from other nodal mature T-cell lymphomas (TCL). Recently, the anaplastic lymphoma kinase (ALK) protein was shown to identify a subgroup of nodal ALCL with an excellent prognosis, whereas ALK-negative ALCLs are more heterogeneous. The aim of this study was to investigate the clinicopathological parameters in relation to clinical behaviour of ALK-negative ALCL compared with other nodal mature TCL, i.e. peripheral TCL, unspecified (PTCL-NOS) and angioimmunoblastic lymphoma (AILT). METHODS AND RESULTS: Clinicopathological data of ALK-positive (n = 28) and ALK-negative (n = 46) ALCL; PTCL-NOS (n = 47); and AILT (n = 12) were analysed for their prognostic significance. While ALK-positive ALCL shows favourable clinical features and a good prognosis, ALK-negative ALCL, PTCL-NOS and AILT are all associated with high age groups, advanced disease stage, and poor prognosis (<45% 5-year survival). In multivariate analysis of overall survival time, performed in the combined group of ALK-negative nodal mature T-cell lymphomas, only age and the International Prognostic Index (IPI) remained independent prognostic parameters, while lymphoma subtype (ALCL versus PTCL-NOS versus AILT) gave no additional information. CONCLUSIONS: The distinction between ALK-negative ALCL and PTCL-NOS or AILT is of limited clinical relevance as they show comparable poor prognosis. In these lymphoma subtypes, only age and the IPI are of significant prognostic value.     

Retinoblastoma protein is frequently absent or phosphorylated in anaplastic large-cell lymphoma

The possible role of retinoblastoma protein (Rb) in the pathogenesis of anaplastic large-cell lymphoma (ALCL) is unknown. We investigated Rb protein expression, both total (phosphorylated and underphosphorylated) and active (underphosphorylated), in four anaplastic lymphoma kinase (ALK)-positive ALCL cell lines (Karpas 299, JB-6, SU-DHL1, and SR-786) by Western blot analysis, and in 67 ALCL tumors (30 ALK-positive, 37 ALK-negative) using immunohistochemical methods. We also used fluorescence in situ hybridization and polymerase chain reaction methods to assess for loss of heterozygosity of the rb gene. The findings were correlated with apoptotic rate assessed by the terminal dUTP nick-end labeling assay. Immunoblots showed high total Rb levels in Karpas 299, SU-DHL1 and SR-786 and relatively lower levels in and JB-6. Underphosphorylated Rb was negative or expressed at low levels in all cell lines. In ALCL tumors, total Rb was detected in 44 (66%) and absent in 23 (34%). The mean apoptotic rate was 3.2% in Rb-negative tumors compared with 2.7%, 2.2%, and 1.2% in tumors with <10%, 10 to 50%, and >50% Rb-positive cells, respectively (P = 0.2, Kruskall-Wallis test). In a subset of 25 total Rb-positive tumors we assessed for underphosphorylated Rb, which was detected in 12 tumors. The detection of only total Rb in the remaining 13 tumors suggests that Rb was phosphorylated. Fluorescence in situ hybridization showed allelic loss of the rb gene in 10 (40%) of 25 tumors analyzed and was significantly associated with absence of Rb expression (P = 0.003). Similar results were obtained for loss of heterozygosity of the 13q14 locus. Five-year progression-free survival for patients with Rb-negative ALCL was 89.4% compared with 47.7% for patients with total Rb-positive ALCL (P = 0.006, log-rank test). Similar trends for progression-free survival held true for patients with ALK-positive and ALK-negative tumors analyzed separately. In conclusion, Rb is absent or phosphorylated in most ALCL cell lines and tumors and absence of Rb expression is associated with better clinical outcome in patients with ALCL.     

963例成熟T和自然杀伤细胞/T细胞淋巴瘤的临床病理特征分析

目的 观察广东地区不同类型成熟T和自然杀伤(NK)细胞/T细胞淋巴瘤及其亚型的临床病理特点.方法 按WHO(2008版)标准重新评估广东地区2002-2006年1137例成熟T和NK/T细胞淋巴瘤患者.由多名血液病理医师复查,补做必要的免疫组织化学染色及原位杂交.结果 963例确诊为成熟T和NK/T细胞淋巴瘤,占同期所有淋巴瘤20.1%(963/4801),发生于结内319例(33.1%),结外644例(66.9%);非特殊型外周T细胞淋巴瘤293例(30.4%);结外鼻型NK/T细胞淋巴瘤281例(29.2%);间变性大细胞淋巴瘤(ALCL)198例(20.6%);血管免疫母细胞性T细胞淋巴瘤(AILT)46例(4.8%).男女比为1.99:1,发病中位年龄为44岁.非特殊型外周T细胞淋巴瘤好发于55～64岁;结外鼻型NK/T细胞淋巴瘤好发于25～54岁;间变性淋巴瘤激酶(ALK)阳性ALCL多见于年轻人而阴性多见于中老年人;AIIJT好发于65～74岁.结论 广东地区成熟T和 NK/T细胞淋巴瘤多见于结外,好发于男性,总体发病与年龄增长无明显关系,但具体类型有不同的年龄侧重群;常见的类型依次为非特殊型外周T细胞淋巴瘤、结外鼻型NK/T细胞淋巴瘤及ALCL;EB病毒感染与NK/T细胞淋巴瘤关系密切.     

The nucleophosmin-anaplastic lymphoma kinase fusion protein induces c-Myc expression in pediatric anaplastic large cell lymphomas

The majority of pediatric anaplastic large cell lymphomas (ALCLs) carry the t(2;5)(p23;q35) chromosomal translocation that juxtaposes the dimerization domain of nucleophosmin with anaplastic lymphoma kinase (ALK). The nucleophosmin-ALK fusion induces constitutive, ligand-independent activation of the ALK tyrosine kinase leading to aberrant activation of cellular signaling pathways. To study the early consequences of ectopic ALK activation, a GyrB-ALK fusion was constructed that allowed regulated dimerization with the addition of coumermycin. Expression of the fusion protein caused a coumermycin-dependent increase in cellular tyrosine phosphorylation and c-Myc immunoreactivity, which was paralleled by a rise in c-myc RNA. To assess the clinical relevance of this observation, c-Myc expression was determined in pediatric ALK-positive and -negative lymphomas. Co-expression of c-Myc and ALK was seen in tumor cells in 15 of 15 (100%) ALK-positive ALCL samples, whereas no expression of either ALK or c-Myc was seen in six of six cases of ALK-negative T-cell lymphoma. C-Myc may be a downstream target of ALK signaling and its expression a defining characteristic of ALK-positive ALCLs.     

DNA damage response and MCL-1 destruction initiate apoptosis in adenovirus-infected cells

Expression of adenovirus E1A deregulates cell proliferation to facilitate viral DNA replication, prompting the initiation of apoptosis signaled primarily through proapoptotic BAK in productively infected cells. We demonstrate here that in uninfected cells, BAK is complexed with the anti-apoptotic BCL-2 family member Myeloid Cell Leukemia 1 (MCL-1). E1A expression during infection resulted in the specific down-regulation of MCL-1 through destabilization of the protein and loss of the mRNA. Upon loss of the MCL-1-BAK complex, BAK complexed with either BAX in proapoptotic E1B mutant adenovirus-infected cells, or with the adenovirus BCL-2 homolog E1B 19K in cells infected with the wild-type virus in which apoptosis is inhibited. Loss of MCL-1 was required to initiate the apoptotic pathway in infected cells as restoration of MCL-1 expression rescued infected cells from E1A-induced apoptosis. Analogous to E1A expression, DNA damage down-regulates MCL-1, and adenovirus infection resulted in the accumulation of phosphorylated H2AX and ataxia-telangiectasia mutant protein (ATM), hallmarks of DNA double-strand breaks. Thus, MCL-1 may function by maintaining BAK in an inactive state, and the loss of MCL-1 upon activation of the DNA damage response, perhaps through replication stress induced in virus infected cells, may be required to initiate the apoptotic response.     

The potential role of BAX and BCL-2 expression in diffuse alveolar damage.

Apoptosis of type II pneumocytes has been identified in diffuse alveolar damage (DAD), is associated with p53 and WAF1 expression, and may be of pathogenetic importance. BAX, a homologue of BCL-2, is induced by p53 and is a promoter of apoptosis. The proapoptotic effect of BAX is negatively regulated by its binding with BCL-2. In this study, we sought to investigate that role of BAX and BCL-2 in DAD. We hypothesized that alterations in BAX and BCL-2 expression may be important in determining the susceptibility of type II pneumocytes and interstitial cells to apoptosis. Twenty-eight cases of DAD and 16 control cases (i.e., lung tissues adjacent to resected tumors) were retrieved from the files of the University of Utah and the Armed Forces Institute of Pathology. Immunohistochemical stains were performed with antigen retrieval by microwave using antibodies recognizing BAX and BCL-2. The percentage of positively staining pneumocytes and interstitial cells was estimated in each case to the nearest 10%. BAX expression was markedly increased in pneumocytes and interstitial cells in DAD compared with control lung tissues. In DAD, BAX was identified on an average of 80% of alveolar pneumocytes (range 30 to 100%) and 70% of interstitial cells (range 20 to 90%). In control lungs, BAX was identified on an average of 10% of pneumocytes (range 0 to 20%) but not in interstitial cells. Focal BCL-2 staining was identified in interstitial myofibroblasts in 7 of 25 cases of DAD but was only identified in bronchiolar epithelium of control lungs. These results suggest that the induction of BAX in DAD may enhance the susceptibility of alveolar epithelial cells to apoptosis, whereas BCL-2 expression may contribute to the absence of apoptosis in interstitial myofibroblasts. Expression of BCL-2 in interstitial myofibroblasts may contribute to the development of pulmonary fibrosis in some patients.