Three distinct commonly deleted regions of chromosome arm 16q in human primary and metastatic prostate cancers

Human prostate cancers frequently show loss of heterozygosity (LOH) at loci on the long arm of chromosome 16 (16q). In this study, we analyzed prostate cancer specimens from 48 patients (Stage B, 20 cases; Stage C, 10 cases; cancer death, 18 cases) for allelic loss on 16q, using either restriction fragment length polymorphism (RFLP)- or polymerase chain reaction (PCR)-based methods. Allelic losses were observed in 20 (42%) of 48 cases, all of which were informative with at least one locus. Detailed deletion mapping identified three distinct commonly deleted regions on this chromosome arm: q22.1–q22.3, q23.2–q24.1, and q24.3-qter. On the basis of a published sex-averaged framework map, the estimated sizes of the commonly deleted regions were 4.7 (16q22.1–q22.3), 17.2 (16q23.2–q24.1) and 8.4 cM (16q24.3-qter). Allelic losses on 16q were observed more frequently in the cancer-death cases (11 of 18; 61%) than in early-stage tumor cases (9 of 30; 30%; P < 0.05). In 7 of 11 patients from whom DNA was available from metastatic cancers as well as from normal tissues and primary tumors, the primary cancer foci had no detectable abnormality of 16q, but the metastatic tumors showed LOH. These results suggest that inactivation of tumor suppressor genes on 16q plays an important role in the progression of prostate cancer. We also analyzed exons 5–8 of the E-cadherin gene, located at 16q22.1, in tumor DNA by means of PCR-single strand conformation polymorphism and direct sequencing, but we detected no somatic mutations in this candidate gene. Genes Chromosom Cancer 17:225–233 (1996). © 1996 Wiley-Liss, Inc.     

Two distinct deleted regions on the short arm of chromosome I in neuroblastoma

The short arm of chromosome Ip is the most frequently altered chromosome segment in neuroblastoma. The alterations, mainly deletions, are thought to be indicative of the presence of a tumor suppressor gene. To further refine the chromosome localization of this gene, we have studied paired constitutional and tumor DNA from a series of 60 patients with neuroblastoma at 2 minisatellite and 23 microsatellite loci dispersed along the short arm of chromosome I. Twenty-two cases (37%) demonstrated loss of heterozygosity (LOH) at one or more loci on 1p. Surprisingly, the pattern of LOH enabled the identification of two distinct consensus regions of deletions. In agreement with previous reports, one region mapped to the distal short arm of chromosome 1. The other region was localized more proximally on 1p. Deletions observed in tumors involve either one or both of these regions. We show that the correlation between NMYC amplification and 1p deletion is limited to the deletions which involve the proximal region either alone or together with the distal region. These results suggest that two tumor suppressor genes on lp might be involved in the development of neuroblastoma. Finally, we show that somatic mutations at microsatellite loci, frequently observed in other types of cancer, are rare events in neuroblastoma. Genes Chromosom Cancer 10:275–281 (1994). © 1994 Wiley-Liss, Inc.     

Immunohistochemical galectin-3 expression in non-melanoma skin cancers

Galectin-3 is a ss-galactoside-binding lectin. It participates in a variety of normal and pathologic processes, including cancer progression. In this study, we evaluated the pattern of expression of galectin-3 in cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), and its correlation with the grade of differentiation in SCC and tumor size. Galectin-3 expression was evaluated by immunohistochemistry in 31 SCCs, 30 BCCs, and 29 non-tumoral skin samples. Galectin-3 expression was higher in normal epidermis than in non-melanoma skin cancers, except for cytoplasmic immunoreactivity in SCC. Cytoplasmic galectin-3 immunoreactivity was significantly higher than nuclear immunoreactivity in non-melanoma skin cancers. Cytoplasmic galectin-3 immunoreactivity was significantly higher in SCC than in both circumscribed and infiltrative BCCs, but no difference was detected between these two types of BCC. Cytoplasmic galectin-3 immunoreactivity predominated within SCCs (p=0.000), and a positive correlation was detected between tumor size and cytoplasmic immunoreactivity (r=0.385, p=0.043). There was no correlation between galectin-3 staining and tumor differentiation and lymph node metastasis. Decreased nuclear galectin-3 expression and cytoplasmic immunoreactivity in tumors are important factors in the progression from the normal to the cancerous state in non-melanoma skin cancers. We speculate that cytoplasmic galectin-3 expression may be one of the factors that contribute to tumor aggressiveness in SCC.     

Delineation of multiple deleted regions in 7q in myeloid disorders.

Loss of chromosome material due to deletions of the long arm of chromosome 7, del(7q), is a consistent finding in all types of myeloid disorders, invariably associated with a poor prognosis. Two different segments, 7q22 and 7q32-q33, have been implicated as critical regions of gene loss associated with these disorders. In the present study, we used fluorescence in situ hybridization (FISH) to characterize the 7q22 breakpoint of an apparently balanced t(7;7)(p13;q22) in an acute myeloid leukemia patient. FISH analysis on bone marrow metaphases from this patient revealed that the sequence corresponding to a series of three ordered cosmids from 7q22 was deleted from one of the der(7) chromosomes. These cosmids contain the human homologue of the Drosophila homeobox gene cut (CUTL1) and span a region of approximately 150 kb. Although the proximal boundary of the deleted segment could not be exactly defined, we estimate the size of this deletion to be approximately 500 kb. Subsequently, we carried out FISH studies using the CUTL1 cosmids on a further 16 patients with deletions of 7q and myeloid disorders. The sequence corresponding to at least two of the cosmids was deleted from the del(7q) in 11 out of 14 cases with a proximal breakpoint within 7q22. Further detailed FISH mapping in this series of 17 patients has identified two other nonoverlapping commonly deleted segments at 7q31-q32 and 7q33, respectively. These data confirm and refine other studies, implying that several different genes on 7q may be involved in the pathogenesis of myeloid diseases. Genes Chromosomes Cancer 25:384-392, 1999.     

Identification of three commonly deleted regions on chromosome arm 6q in human pancreatic cancer

Pancreatic cancer has one of the poorest prognoses among malignant diseases. To understand its molecular mechanisms, we studied allelic losses on the long arm of chromosome 6. Using 55 paired DNAs of tumors and their corresponding normal tissues and 30 microsatellite markers that spanned the entire 6q chromosome arm, we found three distinct regions of common allelic loss: region A, a less than 500-kb region bordered by D6S449 and D6S283 on 6q21 with a loss of heterozygosity (LOH) frequency of 69% (38/55); region B, a 7-cM region bordered by D6S292 and D6S308 on 6q23-q24 with a LOH frequency of 60% (33/55); and region C, a 13-cM region bordered by D6S305 and D6S264 with a LOH frequency of 51% (28/55). We further focused on region A and constructed a physical map using yeast artificial chromosome (YAC) clones, their derived cosmid clones, and bacterial artificial chromosome (BAC) clones. Region A was completely covered by three overlapping BAC clones. Our results in the present study should shed light on the cloning and characterization of tumor suppressor genes in pancreatic carcinogenesis.     

人肝细胞癌染色体1p36.2-p36.3的肿瘤抑制位点的初步鉴定

目的 对肝细胞癌的１号染色体远端可能含有肿瘤抑制基因的精细缺失片段定位,为克隆新的ＴＳＧ提供位点依据。方法 使用１号染色体短臂的４３个微卫星ＤＮＡ多态性标志,其中３０个标志集中分布在１ｐ３６．２－ｐ３６．３,分析了３８例原发性ＨＣＣ的杂合子丢失。结果 ７４％肿瘤至少有１个位点的ＬＯＨ发生在１ｐ３６．２－ｐ;３６．３。     

Delineation of commonly deleted chromosomal regions in meningiomas by high-density single nucleotide polymorphism genotyping arrays

Despite recent advances in the identification of the cytogenetic profiles of meningiomas, a significant group of tumors still show normal karyotypes or few chromosomal changes. The authors analyzed the cytogenetic profile of 50 meningiomas using fluorescence in situ hybridization and high-density (500 K) single nucleotide polymorphism (SNP) arrays. Our results confirm that del(22q) (52%) and del(1p) (16%) (common deleted regions: 22q11.21-22q13.3. and 1p31.2-p36.33) are the most frequent alterations. Additionally, recurrent monosomy 14 (8%), del(6q) (10%), del(7p) (10%), and del(19q) (4%) were observed, while copy number patterns consistent with recurrent chromosomal gains, gene amplification, and copy number neutral loss of heterozygosity (cnLOH) were either absent or rare. Based on their overall SNP profiles, meningiomas could be classified into: (i) diploid cases, (ii) meningiomas with a single chromosomal change [e.g., monosomy 22/del(22q)] and (iii) tumors with ≥2 altered chromosomes. In summary, our results confirm and extend on previous observations showing that the most recurrent chromosomal abnormalities in meningiomas correspond to chromosome losses localized in chromosomes 1, 22 and less frequently in chromosomes 6, 7, 14, and 19, while chromosomal gains and cnLOH are restricted to a small proportion of cases. Finally, a set of cancer-associated candidate genes associated with the TP53, MYC, CASP3, HDAC1, and TERT signaling pathways was identified, in cases with coexisting monosomy 14 and del(1p).     

Preferentially deleted chromosome region 9p21 in large hepatocellular carcinomas

The role of somatic deletions in chromosome 9 and chromosome 22 loci in hepatocellular carcinomas (HCC) was studied. Twenty-one paired HCC and adjacent tumor-free liver tissue samples were examined for loss of heterozygosity at six chromosome 9 and ten chromosome 22 loci. Among informative cases, the highest LOH rates were observed at 9p21 (40% or 4/10 at IFNA) and 9q23 (23% or 3/13 at D9S318). Our observed LOH rate at 9p21 was significantly higher than the background level previously reported for the same tumor type. Clinical data indicate that chromosome 9p21 deletions occurred preferentially in larger tumors (>5 cm diameter). However, a sequence analysis of the MTS1 gene coding region in cases of 9p21 LOH did not reveal any change, suggesting another tumor suppressor gene as the LOH target.     

Delineation of a less than 200 kb minimal deleted region for cardiac malformations on chromosome 7p22

Cardiac malformations are commonly seen in individuals with terminal and interstitial deletions involving chromosome band 7p22. Although these malformations represent a significant cause of morbidity, the dosage-sensitive gene(s) that underlie these defects have yet to be identified. In this report, we describe a 16-month-old male with tetralogy of Fallot, bilateral second branchial arch remnants, and mild dysmorphic features. Array comparative genomic hybridization analysis revealed a less than 400 kb interstitial deletion on chromosome 7p22. The deletion was confirmed by real-time quantitative PCR and FISH analyses and was not detected in samples obtained from the child's parents. Molecular data from this de novo deletion, in combination with data from other isolated 7p deletions in the literature, can be used to define a less than 200 kb minimal deleted region for cardiac malformations on 7p22. This minimal deleted region spans all, or portions, of the coding regions of four known genes-MAD1L1, FTSJ2, NUDT1, and SNX8-and may include upstream regulatory elements of EIF3B. It is likely that one or more of these five genes, alone or in combination, plays an important, yet previously uncharacterized, role in cardiac development.     

Commonly deleted regions on the long arm of chromosome 21 in differentiated adenocarcinoma of the stomach

During an allelotype analysis of differentiated adenocarcinoma of the stomach, we observed frequent loss of heterozygosity (LOH) on several chromosomes including the long arm of chromosome 21 (21q). Therefore, we analyzed DNA isolated from 45 tumors for LOH at 10 loci on 21q by using polymorphic microsatellite markers. In 20 (44%) of 45 tumors, we detected LOH at single or multiple loci on 21q. Deletion mapping of these 20 tumors revealed two separate commonly deleted regions. Our findings suggest that 21q contains at least two potential tumor suppressor genes which play crucial roles in the development of differentiated adenocarcinoma of the stomach. Genes Chromosom. Cancer 18:318–321, 1997. © 1997 Wiley-Liss, Inc.     

Comparative genomic hybridization of microdissected familial ovarian carcinoma: two deleted regions on chromosome 15q not previously identified in sporadic ovarian carcinoma

The vast majority of familial ovarian cancers harbor a germline mutation in either the breast cancer gene BRCA1 or BRCA2 tumor suppressor genes. However, mutations of these genes in sporadic ovarian cancer are rare. This suggests that in contrast to hereditary disease, BRCA1 and BRCA2 are not commonly involved in sporadic ovarian cancer and may indicate that there are two distinct pathways for the development of ovarian cancer. To characterize further differences between hereditary and sporadic cancers, the comparative genomic hybridization technique was employed to analyze changes in copy number of genetic material in a panel of 36 microdissected hereditary ovarian cancers. Gains at 8q23-qter (18 of 36, 5 cases with high-level amplifications), 3q26.3-qter (18 of 36, 2 cases with high-level amplifications), 11q22 (11 of 36) and 2q31-32 (8 of 36) were most frequent. Losses most frequently occurred (in decreasing order of frequency) on 8p21-pter (23 of 36), 16q22-pter (19 of 36), 22q13 (19 of 36), 9q31-33 (16 of 36), 12q24 (16 of 36), 15q11-15 (16 of 36), 17p12-13 (14 of 36), Xp21-22 (14 of 36), 20q13 (13 of 36), 15q24-25 (12 of 36), and 18q21 (12 of 36). Comparison with the literature revealed that the majority of these genetic alterations are also common in sporadic ovarian cancer. Deletions of 15q11-15, 15q24-25, 8p21-ter, 22q13, 12q24 and gains at 11q22, 13q22, and 17q23-25, however, appear to be specific to hereditary ovarian cancer. Aberrations at 15q11-15 and 15q24-25 have not yet been described in familial ovarian cancer. In these regions, important tumor suppressor genes, including the hRAD51 gene, are located. These and other yet unknown suppressor genes may be involved in a specific carcinogenic pathway for familial ovarian cancer and may explain the distinct clinical presentation and behavior of familial ovarian cancer.     

TP53 mutations in human skin cancers

The p53 gene (TP53) is mutated in numerous human cancers. We have used it as a molecular target to characterize the induction of mutations in human skin cancers. About 50% of all skin cancers in normal individuals exhibit p53 mutations. This frequency rises to 90% in skin cancers of patients with the DNA-repair deficiency known as xeroderma pigmentosum (XP). These mutations are characterized by a specific signature, attributed to the ultraviolet uvB part of the solar spectrum. In this review, we will describe different p53 mutation spectra, in relation to the various histopathological types of skin cancers such as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and malignant melanoma as well as to the DNA repair efficiency of the patients. In particular, different mutational hot spots are found among the various spectra. We have tried to elucidate them in terms of induced DNA lesion hot spots, as well as speed of local nucleotide excision repair (NER) or sequence effects. The molecular analysis of these mutagenic characteristics should help in the understanding of the origin of human skin cancers in the general population.     

The random development of LOH on chromosome 9q in superficial bladder cancers

Allelic loss on chromosome 9q is a very frequent event in bladder carcinogenesis. In recent years, efforts have been directed towards identifying the postulated tumour suppressor genes on this chromosome arm by deletion mapping and mutation analysis. However, no convincing candidate genes have been identified. This paper describes the development of chromosome 9q alterations in multiple recurrent superficial bladder cancers of ten patients and shows that loss of heterozygosity (LOH) on this chromosome is almost never the characteristic first step. The regions of loss are multiple and variable in different tumours from the same patient and expand in subsequent tumours. Moreover, the regions of loss vary from patient to patient. It is concluded that even if 9q harbours a bladder cancer gatekeeper gene, it is unlikely that the gene will be identified through LOH analysis alone.     

The karyotype of the glucocorticoid-sensitive, lymphoblastic human T-cell line CCRF-CEM shows a unique deleted and inverted chromosome 9

Chromosome karyotypes were prepared from the highly glucocorticoid-sensitive clone C7 of the human acute lymphoblastic leukemia T-cell line CCRF-CEM. The modal number of chromosomes is 47, and one chromosome #9 has a pericentric inversion of the heterochromatin region (9qh) plus a deletion of the short arm. In most cells, there is an extra chromosome #20. All other chromosomes appear to be normal. Examination of the uncloned line CCRF-CEM (ATCC CCL 119), which was frozen away shortly after the line was originated and has undergone fewer passages than CEM C7, also revealed the same abnormality of chromosome #9. Each of 10 other clones isolated from CCRF-CEM in this laboratory also contained the abnormal chromosome #9.     

Allelic losses in human chromosome II in lung cancers

The relatively frequent loss of heterozygosity at loci on the short arm of chromosome 11 in human lung cancers has suggested the presence of a putative tumor suppressor gene. For location of the gene, a fine deletion map of human chromosome 11 was constructed by analysis of DNAs from 79 lung cancers with 31 sequence-tagged-site markers that dotted chromosome 11 and detected polymorphic changes in nucleotide sequences. The results showed that three regions, 11p 12-p 15, 11q12, and 11 q14-q24, were commonly deleted in a considerable number of cancers, indicating the possible presence of more than one tumor suppressor gene. The range of deletion in the 11p15 region was estimated to be 4.5 megabases. That in the 11q24-q24 region was divided into two portions: one was 3 cM in length, and the other was longer and could not be specified because of lack of appropriate markers. The deletion in the 11q12 region was so short that two markers flanking the region could not be identified by genetic analysis. © 1995 Wiley-Liss, Inc.     

Angiogenesis and host immune response contribute to the aggressive character of non-melanoma skin cancers in renal transplant recipients

Mackenzie K A, Miller A P, Hock B D, Gardner J, Simcock J W, Roake J A, Dachs G U, Robinson B A & Currie M J
(2011) Histopathology  58 , 875–885
Angiogenesis and host immune response contribute to the aggressive character of non‐melanoma skin cancers in renal transplant recipients Aims: The aim of this study was to determine the contribution of tumour angiogenesis to the aggressive growth of non‐melanoma skin cancers (NMSCs) in renal transplant recipients (RTRs). Methods and results: The study cohort included RTRs (n = 38) with formalin‐fixed paraffin‐embedded tumour samples available from first post‐transplant NMSC (NMSC1) surgically excised at Christchurch Hospital, New Zealand, from 1997 to 2007. Comparable samples excised from immunocompetent individuals (ICIs) (n = 36) were selected to accommodate confounding factors. Markers of tumour angiogenesis were evaluated by immunohistochemistry, and analysed for associations with clinicopathological variables. As compared with ICIs, RTRs had a higher proportion of tumours with high microvessel density (P = 0.008), high proliferating capillary index (P < 0.0001) and low microvessel pericyte coverage index (P < 0.0001), and RTRs had a shorter cumulative second NMSC (NMSC2)‐free interval (P < 0.0001). ICIs had a higher proportion of tumours with a ‘marked’ number of vascular endothelial growth factor (VEGF)‐A‐positive leukocytes than RTRs (P = 0.04), and RTRs with a ‘moderate/marked’ number of VEGF‐A‐positive leukocytes had longer cumulative NMSC2‐free intervals than those with a ‘minimum’ number (P = 0.02). Conclusions: This study demonstrates increased tumour angiogenesis in NMSC in RTRs, and suggests a role for VEGF‐A‐positive peritumoural leukocytes in suppressing NMSC development.     

Comparative transforming potential of different human papillomaviruses associated with non-melanoma skin cancer

It is well established that high-risk human papillomaviruses (HPVs) that infect mucosal epithelia are the causative agents of cervical cancer. In contrast, the association of cutaneo-tropic HPV types with the development of non-melanoma skin cancer (NMSC) is less well defined. In this study, we have analysed the in vitro transforming potential of various cutaneous HPV types. Using oncogene cooperation assays with activated ras, we have shown that diverse cutaneous types, including 12, 14, 15, 24, 36 and 49, have significant transforming potential. Interestingly, most of this activity appears to be encoded by the E6 gene product. In contrast, the common HPV-10 exhibits no significant transforming potential in these assays. This difference may be a reflection of different patterns of cellular localization, with transforming E6s being nuclear and non-transforming being cytoplasmic. These results provide molecular support for a role of these viruses in the development of certain human malignancies.