横纹肌肉瘤中HMGA1和HMGA2的表达及其临床意义

目的 探讨高迁移率蛋白A1(HMGA1)和高迁移率蛋白A2(HMGA2)在横纹肌肉瘤(rhabdomyosarcoma,RMS)中的表达特点及其与临床病理参数、细胞增殖的关系.方法 应用免疫组化法分别检测39例RMS和10例正常横纹肌组织中HMGA1、HMGA2和Ki-67蛋白表达水平;原位杂交法分别检测39例RMS中HMGA1和HMGA2基因mRNA的表达.结果 HMGA1和HMGA2在RMS中的蛋白阳性表达率分别为76.9%(30/39)和64.1%(25/39),表达水平分别高于正常横纹肌组织(P<0.05);mRNA阳性表达率分别为69.2%(27/39)和66.7%(26/39),表达水平分别高于正常横纹肌组织(P<0.05).HMGA1、HMGA2在蛋白水平的表达与其各自的mRNA水平表达之间具有较好一致性.两者分别在胚胎型(ERMS)和腺泡型(ARMS)中的表达差异无统计学意义(P>0.05),而在不同分化程度之间的表达差异有统计学意义(P<0.05);在有复发或转移的病例与无复发或转移的病例中表达差异有统计学意义(P<0.05);在Ki-67阳性的高增殖组与Ki-67阴性的低增殖组之间的表达差异无统计学意义(P>0.05).结论 HMGA1和HMGA2过表达可能与RMS的发生、发展密切相关,有望成为判断该肿瘤预后的指标之一,并为靶向治疗提供依据.     

Odontogenic myxofibroma with HMGA2 overexpression and HMGA2 rearrangement

Odontogenic myxofibromas are variants of odontogenic myxomas that contain considerable amounts of collagen fibers in the myxoid stroma. Cytogenetic studies of odontogenic myxomas/myxofibromas have rarely been reported. This report describes the first case of an odontogenic myxofibroma presenting with HMGA2 protein overexpression and HMGA2 rearrangement in a 40-year-old woman. A 2.7-cm tumor in the premolar region of the right mandible was curettaged. There was no evidence of recurrence or metastasis at 12 months after the surgery. Histological examination revealed that the tumor comprised spindle or stellate cells with mild nuclear pleomorphism, abundant myxoid matrix and partly dense collagen fibers. Mitotic figures were rarely observed. Immunohistochemically, the tumor cells were diffusely positive for vimentin and HMGA2. Less than 1% of the tumor cells were positive for Ki-67. We detected split signals by interphase fluorescence in situ hybridization (FISH) in paraffin sections using HMGA2 break-apart probes. The breaks were certainly located within or near the HMGA2 gene. No rearrangement of the FUS gene was detected by FISH, implying discrimination from low-grade fibromyxoid sarcoma. It is suggested that HMGA2 rearrangement and HMGA2 protein overexpression may be associated with the tumorigenesis of odontogenic myxomas/myxofibromas, similar to the case for many other benign mesenchymal tumors.     

Prognostic significance of the MDM2/HMGA2 ratio and histological tumor grade in dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a relatively common soft tissue sarcoma that results from the progression of well‐differentiated liposarcoma (WDLPS). This study aimed to investigate the progression process and to clarify the pathological and genetic factors related to poor prognosis in DDLPS. In 32 DDLPS cases and five WDLPS cases, genetic factors were analyzed by custom comparative genomic hybridization (CGH) array, which was designed to densely cover gene regions known to be frequently amplified in WD/DDLPS. The analyses comparing primary and metastatic lesions and those comparing histologically different areas in the same tumor revealed intra‐tumoral genetic heterogeneity and progression. According to a prognostic analysis comparing the good‐prognosis and the poor‐prognosis groups, we selected MDM2 and HMGA2 as candidate genes associated with poor and good prognosis, respectively. The ratios of the amplification or gain levels of MDM2 and HMGA2 expressed in log ratios (log[MDM2/HMGA2] = log[MDM2]‐log[HMGA2]) were significantly associated with prognosis. An amplification or gain level of MDM2 that was more than twice that of HMGA2 (MDM2/HMGA2 > 2, log[MDM2/HMGA2] > 1) was strongly related to poor OS (P < .001) and poor distant metastasis‐free survival (DMFS) (P < .001). In the pathological analysis of 44 cases of DDLPS, histological tumor grade, cellular atypia, and MDM2 immunoreactivity were related to overall survival (OS), while HMGA2 immunoreactivity tended to be associated with OS. Cellular atypia was also associated with DMFS. In conclusion, histological grade and MDM2 expression were determined to be prognostically important, and the MDM2/HMGA2 amplification or gain ratio was found to have significant prognostic value by the custom CGH array analysis.     

Insights into the Regulation of a Common Variant of HMGA2 Associated with Human Height During Embryonic Development

Early genetic studies in the mouse and chicken identified the HMGA oncogene as a candidate that regulates body height. Subsequent genome-wide SNP studies revealed a significant association of rs1042725 genotypes CT and CC in the 3’ UTR of HMGA2 with human height. Together, these studies indicated that HMGA2 expression levels during prenatal development might be a critical factor that contributes to the height phenotype. In the present study, we sought to gain insight into the regulation of HMGA2 during human embryonic development and provide evidence that the rs1042725 genotype is unlikely to affect HMGA2 levels in pluripotent human embryonic stem cells (hESCs). This implies that hESCs in the inner cell mass of blastocysts are most likely not involved in determining the human height phenotype associated with this SNP. By applying a computational approach and cell-based reporter assays, we then identified miR-196b as a candidate microRNA that could contribute to SNP-specific expression of HMGA2 during human prenatal development. We briefly discuss this result in the context of other known functions for miR-196b during vertebrate development.     

HMGA2 is commonly expressed in uterine serous carcinomas and is a useful adjunct to diagnosis

McCluggage W G, Connolly L E, McBride H A, Kalloger S & Gilks C B (2012) Histopathology  60, 547–553
HMGA2 is commonly expressed in uterine serous carcinomas and is a useful adjunct to diagnosis Aims: Serous carcinoma is the prototype of type 2 uterine carcinoma. In many cases, establishing a diagnosis is straightforward, but problems can arise in that papillary variants of endometrioid carcinoma may be mistaken for serous carcinoma, and glandular variants of serous carcinoma may be misdiagnosed as endometrioid carcinoma. Markers such as p53, oestrogen receptor and p16 may be of use in problematic cases, but there is overlap and these may not therefore be of value in an individual case. It has been shown recently that high‐mobility group AT‐hook 2 (HMGA2) is expressed by most ovarian serous carcinomas, and our aim was to ascertain whether it is also expressed in uterine serous carcinoma and of value in its distinction from endometrioid carcinoma. Methods and results: Whole tissue sections of uterine serous (n = 33) and endometrioid (n = 38) carcinoma were immunostained using HMGA2 antibody. As many of the diagnostic problems relate to the distinction between serous carcinoma and grade 3 endometrioid carcinoma, tissue microarrays (TMAs) containing uterine serous (n = 71) and uterine grade 3 endometrioid (n = 68) carcinomas were also stained. Staining was classified as negative (totally negative or occasional nuclei positive), 1+ (<10% of nuclei positive), 2+ (10–49% of nuclei positive), 3+ (50–74% of nuclei positive), or 4+ (≥75% of nuclei positive). On the whole tissue sections, positive staining was also classified as weak, moderate, or strong, and an immunohistochemical composite score, taking into account both extent and intensity of staining, was calculated. On whole tissue sections, there was a statistically significant difference between HMGA2 staining in serous and endometrioid carcinomas with regard to both extent and composite score, with higher expression in serous carcinomas (P < 0.0001). Thirty of 33 (91%) serous carcinomas were positive, usually with diffuse (3+ or 4+) staining. All five cases of serous endometrial intraepithelial carcinoma (EIC) (the postulated precursor of uterine serous carcinoma) were positive, as were 14 of 38 (37%) endometrioid carcinomas, usually with 1+ or 2+ staining. There was a statistically significant difference in HMGA2 staining in the TMAs between the serous and grade 3 endometrioid carcinomas, with higher expression in the former (P < 0.0001). Conclusions: Immunoreactivity for HMGA2 is diffusely positive in whole tissue sections in most uterine serous carcinomas and negative in most endometrioid carcinomas, although, as with other markers, there is overlap in individual cases. In conjunction with other markers, HMGA2 may be of value in problematic uterine carcinomas where the differential diagnosis includes serous and endometrioid carcinoma. As HMGA2 is expressed in serous EIC, this suggests that it may be implicated in the early development of uterine serous carcinoma.     

HMGA2在胃癌细胞上皮-间充质转化中的作用

目的:探讨HMGA2在胃癌细胞上皮-间充质转化(EMT)中的作用及机制。方法:采用Western blot和RT-qPCR实验检测不同分化程度的人胃癌细胞株MKN45、MKN28和SGC7901以及人永生化胃黏膜上皮细胞株GES-1中HMGA2的表达水平;采用脂质体转染法将pcDNA3.0-HMGA2质粒转染至MKN28细胞中,将si-HMGA2干扰片段转染至MKN45细胞中,并采用Western blot和RT-qPCR实验检测转染效率;CCK-8实验检测HMGA2上调对MKN28细胞活力的影响以及HMGA2下调对MKN45细胞活力的影响;采用细胞迁移和侵袭实验检测HMGA2上调对MKN28细胞迁移和侵袭能力的影响;采用Western blot和RT-qPCR实验检测HMGA2过表达对MKN28细胞EMT相关标志蛋白上皮型钙黏蛋白(E-cadherin)、神经型钙黏蛋白(N-cadherin)和波形蛋白(vimentin)表达的影响以及敲减HMGA2表达对MKN45细胞E-cadherin、N-cadherin和vimentin表达的影响;采用RT-qPCR实验检测过表达HMGA2的MKN28细胞Wnt/β-catenin信号通路相关分子表达的变化。结果:HMGA2在不同分化程度的胃癌细胞中的表达水平是不同的(P0.05)。上调MKN28细胞HMGA2的表达水平能够抑制细胞活力(P0.05);而在MKN45细胞中下调HMGA2的表达水平能够增强细胞活力(P0.05)。上调MKN28细胞HMGA2的表达水平能够促进细胞的迁移和侵袭能力(P0.05),且E-cadherin表达降低,N-cadherin和vimentin表达升高(P0.05);敲减HMGA2在MKN45细胞的表达水平使E-cadherin表达升高,而N-cadherin和vimentin表达降低(P0.05)。上调MKN28细胞中HMGA2的表达水平,细胞内Wnt/β-catenin通路的β-catenin及其下游分子c-Myc和cyclin D1的mRNA表达水平显著增加(P0.05)。结论:HMGA2与胃癌细胞迁移和侵袭能力密切相关,并且能够通过激活细胞内Wnt/β-catenin通路,促进胃癌细胞EMT。     

胃癌中HMGA2与HDAC6表达的临床意义及其相关性

目的检测胃癌中高迁移率族蛋白2(HMGA2)和组蛋白去乙酰化酶6(HDAC6)在胃癌中的表达情况及相关关系,分析其与临床病理特征的关系。方法分别用免疫组织化学法、Western blot和real-time PCR检测82例配对人胃癌、癌旁及正常组织中HMGA2和HDAC6的蛋白及mRNA表达,并分析其与临床病理参数的关系及两者表达的相关性。结果胃癌组织中HMGA2和HDAC6蛋白阳性表达率分别为69.51%(57/82)和65.85%(54/82),明显高于癌旁组织14.63%(12/82)、12.20%(10/82)和正常组织9.76%(8/82)、7.32%(6/82)(P0.05);胃癌组织HMGA2、HDAC6蛋白和mRNA表达较癌旁组织及正常组织高(P0.05),且两者表达水平与肿瘤的临床分期和淋巴结转移相关(P0.05);HMGA2和HDAC6在胃癌组织中的表达呈明显正相关(r=0.56,P0.05)。结论 HMGA2和HDAC6基因在胃癌组织中存在高表达且共存现象,可能与胃癌恶性程度有关。     

下调HMGA2基因表达对改善骨肉瘤U2OS细胞恶性表型的实验研究

目的:研究HMGA2表达在维持人骨肉瘤U2OS细胞恶性表型中的作用,为基因靶向治疗提供理论依据。方法:采用基于DNA的shRNA表达载体HMGA2-shRNA,稳定转染人骨肉瘤U2OS细胞,下调其HMGA2表达水平,并应用RT-PCR技术检测其对HMGA2基因的沉默效果;经Cell Counting Kit-8(CCK8)测定、Hoechst33342染色荧光显微镜观察及Boyden小室法分别检测细胞增殖、凋亡及迁移情况;实时定量RT-PCR检测mRNAs表达水平。结果:稳定转染靶向HMGA2的shRNA可特异性下调U2OS细胞HMGA2 mRNA表达水平;其作用结果使细胞的增殖和迁移能力受到明显抑制,自发凋亡率及Caspase 3和Caspas 9基因表达水平显著升高。结论:HMGA2基因异常表达在维持人骨肉瘤U2OS细胞恶性表型中起重要作用,靶向HM-GA2的基因治疗可能为骨肉瘤治疗带来新希望。     

Comparative analysis of AKT and the related biomarkers in uterine leiomyomas with MED12, HMGA2, and FH mutations

Uterine leiomyomas (ULM) are histologically and molecularly heterogeneous and clinically they grow at vastly different rates. Several driver gene mutations have been identified in ULM, including MED12 mutations, HMGA2 overexpression, and biallelic FH inactivation. ULM with different driver mutant genes may use different molecular pathways, but currently no clear correlation between gene mutations and growth related pathways has been established. To better define this relationship, we collected ULM with MED12 (n = 25), HMGA2 (n = 15), and FH (n = 27) mutations and examined the sex steroid hormone, cell cycle, and AKT pathway genes by immunohistochemistry. While ER and PR were highly expressed in all types of ULM, FH ULM showed lower ER expression and higher PR expression. HMGA2 tumors had significantly higher levels of AKT signaling and mitogenic activity than other ULM types. HMGA2 activated AKT signaling through upregulation of IGF2BP2. Silencing HMGA2 in ULM cells resulted in downregulation of AKT and upregulation of p16 and p21, which eventually led to cell senescence. HMGA2 overexpression in ULM is not only related to tumor development but also plays a role in controlling cellular proliferation through the AKT pathway.     

Ultrasonographic Measurement of Splenic Length in Relation with Height in Bihari Adult Population a Prospective Study

Spleen, the largest ductless gland in the body, shows variations in its size and weight at different periods of life, in different individuals, and in the same individual under different conditions. The splenic size may give information regarding diagnosis and course of various gastrointestinal and haematological diseases so the estimation of the splenic size in vivo is often important in the diagnosis, treatment and prognosis of a variety of disorders. The present study was done to determine the normal range of length of spleen in correlation with the height of adult male and female subjects. A total of 160 patients, 80 males and 80 females were selected. Height of each individual was measured and their splenic length was determined by ultrasonography. It was observed that the length of spleen increased with increase in the height in both male and female. The dimension was less in female than that of male with corresponding body height.     

The 12q14 microdeletion syndrome: six new cases confirming the role of HMGA2 in growth

We report six patients with array deletions encompassing 12q14. Out of a total of 2538 array investigations carried out on children with developmental delay and dysmorphism in three diagnostic testing centres, six positive cases yielded a frequency of 1 in 423 for this deletion syndrome. The deleted region in each of the six cases overlaps significantly with previously reported cases with microdeletions of this region. The chromosomal range of the deletions extends from 12q13.3q15. In the current study, we report overlapping deletions of variable extent and size but primarily comprising chromosomal bands 12q13.3q14.1. Four of the six deletions were confirmed as de novo events. Two cases had deletions that included HMGA2, and both children had significant short stature. Neither case had osteopoikilosis despite both being deleted for LEMD3. Four cases had deletions that ended proximal to HMGA2 and all of these had much better growth. Five cases had congenital heart defects, including two with atrial septal defects, one each with pulmonary stenosis, sub-aortic stenosis and a patent ductus. Four cases had moderate delay, two had severe developmental delay and a further two had a diagnosis of autism. All six cases had significant speech delay with subtle facial dysmorphism.     

Polymorphism of Arylamine-N-acetyltransferase 2 Gene Is Associated with the Risk of Atopic Dermatitis

A case—control study was conducted to evaluate the relationship between C481T and G590A polymorphisms of arylamine-N-acetyltransferase 2 and predisposition to atopic dermatitis in children. Double heterozygote 481C/T and 590G/A in girls is a factor of resistance to atopic dermatitis, especially in the absence of smoking-related effects.__________Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 6, pp. 628–631, June, 2005     

Genetic Variation in Osteopontin Gene Is Associated with Susceptibility to Sarcoidosis in Slovenian Population

Sarcoidosis is a systemic inflammatory disease characterised by appearance of granulomas. Precise etiology has not been elucidated. Osteopontin (Opn) is a Th1 cytokine whose levels have been found increased in granulomas and serum samples from patients with sarcoidosis. We investigated whether genetic variation in Osteopontin gene (OPN) gene contributes to susceptibility to sarcoidosis. Haplotype-block structure in the OPN gene region was investigated using data from HapMap project. Three representative SNPs have been selected from each block of SNPs in linkage disequilibrium (rs11730582-C/T, rs11728697-C/T and rs4754-C/T). Genotyping was performed using TaqMan SNP Genotyping Assays on a sample of 165 patients and 284 controls. Statistical analyses of association were performed using Chi-Square test and algorithms implemented in the haplo.stats and PHASE packages. Genotyping analysis revealed a significant difference in genotype frequencies at rs4754 polymorphism in groups of patients and controls under recessive genetic model (p=0.036, OR=1.99, 95%CI=1.04-3.82), CC homozygotes being significantly over-represented in the patients group. However these results failed to reach significance after correction for multiple testing (p=0.25). The frequencies of predicted haplotypes differed between patient and control groups, frequency of TTT haplotype was found to be significantly decreased in the group of patients with sarcoidosis (p=0.014, OR=0.40, 95%CI=0.20-0.79). Our results suggest that variation in the OPN gene might be significantly associated with sarcoidosis and that the TTT haplotype in OPN may act as a protective factor in sarcoidosis.