A Congenic Line of the DDD Mouse Strain, DDD/1-Mtv-2/Mtv-2: Establishment and Mammary Tumorigenesis

A single dominant gene on chromosome 18, Mtv-2 , controls both the early appearance of mammary tumors and expression of mouse mammary tumor virus (MMTV) in the milk. A congenic DDD mouse strain, DDD/1- Mtv-2 / Mtv-2 (DDD- Mtv-2 ), was developed by introducing this gene from GRS/AJms (GR) into DDD/1 mice by repeating 12 backcrosses and subsequent inbreeding using mammary tumors as a marker for selection. Southern blot analysis of the liver DNA from the resulting congenic mice with Eco RI and MMTV-U3 probe revealed that two DNA fragments corresponding to Mtv-2 were specifically transferred from GR to congenic mice. Detection of MMTV-gp52 antigen in the mammary gland and mammary tumor development in DDDfDDD- Mtv-2 mice demonstrated the production of infectious mature MMTV by Mtv-2 in congenic mice. About 80% of breeding DDD- Mtv-2 females developed mammary tumors in the course of one-year follow-up. The tumor incidence was lower and the tumor age higher than those in GR mice, suggesting less active functioning of the gene on the DDD genetic background. About 70% of these tumors were morphologically classified as pale cell and type P carcinomas peculiar to GR mice. The gene seemed to control the histologic features of mammary tumors. Congenic mice carried an MMTV provirus in an incomplete form on Y chromosome. The DDD- Mtv-2 strain will provide a new model for biological and molecular researches into mouse mammary tumorigenesis.     

Deletion of WT1 and WIT1 Genes and Loss of Heterozygosity on Chromosome 11p in Wilms Tumors in Japan

Six of 39 sporadic Wilms tumors had gross homozygous or hemizygous WT1 and WIT1 deletions. Two Wilms tumor-aniridia-genitourinary abnormalities-mental retardation syndrome patients had total hemizygous WT1 and WIT1 deletions in both constitutional and nonsporadic type tumor cells. Four of the 8 tumors with WT1 and WIT1 deletions showed loss of constitutional heterozygosity (LOH) for markers limited to the 11p13 region. Seven of 19 Wilms tumors with neither WT1 nor WIT1 deletions also had LOH on 11p; 4 in the 11p15–11p13 region, one in the 11p15 and possibly also 11p13 regions, and two solely in the 11lp15 region. Thus, 15 of the 41 Wilms tumors (37%) had WT1 and WIT1 deletions or LOH on 11p, and only 2 of the 27 tumors whose nonneoplastic normal tissues were available for study showed LOH limited to the 11p15 region. None of the 7 non-Wilms childhood renal tumors showed WT1 or WIT1 deletions, or LOH on 11p. These data suggest that Japanese Wilms tumors may be characterized by a higher incidence of the gross WT1 deletion and a lower incidence of LOH limited to the 11p15 region than the Caucasian counterparts. These moleculargenetic features may be contributing to the lower incidence of Wilms tumors in Japanese children than in Caucasian ones.     

Sabutoclax, a Mcl-1 Antagonist, Inhibits Tumorigenesis in Transgenic Mouse and Human Xenograft Models of Prostate Cancer

Resistance to available therapeutic agents has been a common problem thwarting progress in treatment of castrate-resistant and metastatic prostate cancer (PCa). Overexpression of the Bcl-2 family members, including Mcl-1, in PCa cells is known to inhibit intracellular mitochondrial-dependent apoptosis. Here we report the development of a novel transgenic mouse model that spontaneously develops prostatic intraepithelial neoplasia and adenocarcinoma by the inducible, conditional knockout of transforming growth factor β receptor type II in stromal fibroblastic cells (Tgfbr2^ColTKO). The Tgfbr2^ColTKO prostate epithelia demonstrated down-regulation of luminal and basal differentiation markers, as well as Pten expression and up-regulation of Mcl-1. However, unlike in men, Tgfbr2^ColTKO prostates exhibited no regression acutely after castration. The administration of Sabutoclax (BI-97C1), a pan-active Bcl-2 protein family antagonist mediated apoptosis in castrate-resistant PCa cells of Tgfbr2^ColTKO mice and human subcutaneous, orthotopic, and intratibial xenograft PCa models. Interestingly, Sabutoclax had little apoptotic effect on benign prostate tissue in Tgfbr2^ColTKO and wild-type mice. Sabutoclax was able to block c-Met activation, a critical axis in PCa metastatic progression. Further, Sabutoclax synergistically sensitized PC-3 cells to the cytotoxic effects of docetaxel (Taxotere). Together, these data suggest that Sabutoclax inhibits castrate-resistant PCa alone at the primary and bone metastatic site as well as support sensitivity to docetaxel treatment.     

Allele Loss on Chromosome 11 in a Pituitary Tumor from a Patient with Multiple Endocrine Neoplasia Type 1

We have examined the allele loss of chromosome 11 in a pituitary tumor from a patient with familial multiple endocrine neoplasia type 1 (MEN 1). The extensive loss of chromosome 11, including loci of D11S149, HRAS1 and F2 , was detected by the loss of heterozygosity. All of the lost alleles of these loci were transmitted from the unaffected father and not from an affected mother. This is the first evidence of allele loss of chromosome 11 in a pituitary tumor of MEN 1 and supports the idea that similar allelic deletion of MEN1 locus on chromosome 11 is the common genetic basis for tumorigenesis in the pituitary, endocrine pancreas, and parathyroid gland in MEN 1.     

Deletion of Atbf1/Zfhx3 In Mouse Prostate Causes Neoplastic Lesions,Likely by Attenuation of Membrane and Secretory Proteins and Multiple Signaling Pathways

The ATBF1/ZFHX3 gene at 16q22 is the second most frequently mutated gene in human prostate cancer and has reduced expression or mislocalization in several types of human tumors. Nonetheless, the hypothesis that ATBF1 has a tumor suppressor function in prostate cancer has not been tested. In this study, we examined the role of ATBF1 in prostatic carcinogenesis by specifically deleting Atbf1 in mouse prostatic epithelial cells. We also examined the effect of Atbf1 deletion on gene expression and signaling pathways in mouse prostates. Histopathologic analyses showed that Atbf1 deficiency caused hyperplasia and mouse prostatic intraepithelial neoplasia (mPIN) primarily in the dorsal prostate but also in other lobes. Hemizygous deletion of Atbf1 also increased the development of hyperplasia and mPIN, indicating a haploinsufficiency of Atbf1. The mPIN lesions expressed luminal cell markers and harbored molecular changes similar to those in human PIN and prostate cancer, including weaker expression of basal cell marker cytokeratin 5 (Ck5), cell adhesion protein E-cadherin, and the smooth muscle layer marker Sma; elevated expression of the oncoproteins phospho-Erk1/2, phospho-Akt and Muc1; and aberrant protein glycosylation. Gene expression profiling revealed a large number of genes that were dysregulated by Atbf1 deletion, particularly those that encode for secretory and cell membrane proteins. The four signaling networks that were most affected by Atbf1 deletion included those centered on Erk1/2 and IGF1, Akt and FSH, NF-κB and progesterone and β-estradiol. These findings provide in vivo evidence that ATBF1 is a tumor suppressor in the prostate, suggest that loss of Atbf1 contributes to tumorigenesis by dysregulating membrane and secretory proteins and multiple signaling pathways, and provide a new animal model for prostate cancer.     

线粒体蛋白Bcl-2和Bax在肿瘤发生中作用的初步探讨

目的:研究线粒体蛋白(MAB1273)、Bcl-2、Bax在肾细胞癌(RCC)组织内的表达及相关性分析.方法:采用免疫组织化学SP方法检测9例嗜酸细胞瘤、6例嫌色细胞癌、23例透明细胞癌以及12例正常肾组织中MABl273、Bcl-2和Bax蛋白的表达.结果:MABl273和Bel-2在嗜酸细胞瘤、嫌色细胞癌、透明细胞癌中表达明显高于正常肾组织(P=0.006,P=0.008).Bax在各组间表达无明显差异(P=0.057).通过秩相关分析,MAB1273的表达与Bcl-2的表达呈正相关(r=0.341,P=0.015),而Bcl-2表达与Bax表达呈负相关(r=-0.287,P=0.043).结论:线粒体蛋白及Bcl-2的高表达、Bax低表达可能共同参与了肾嗜酸细胞瘤、嫌色细胞癌及透明细胞癌的发生,提示线粒体蛋白表达异常参与RCC细胞凋亡调控过程.     

Diarrhetic Shellfish Toxin, Dinophysistoxin-1, Is a Potent Tumor Promoter on Mouse Skin

Dinophysistoxin-1, 35-methylokadaic acid, is a causative agent of diarrhetic shellfish poisoning. The biological activities and tumor-promoting activity of dinophysistoxin-1 were studied together with those of okadaic acid and 7-O-palmitoyl okadaic acid. Dinophysistoxin-1 is a skin irritant and induces ornithine decarboxylase in mouse skin with the same potency as okadaic acid. 7-O-Palmitoyl okadaic acid induced a lower activity than the other compounds. Dinophysistoxin-1 inhibited the specific [³H]okadaic acid binding to a participate fraction of mouse epidermis. The binding affinities of dinophysistoxin-1 and okadaic acid to a particulate fraction were almost the same. Dinophysistoxin-1 showed a tumor-promoting activity as strong as that of okadaic acid in a two-stage carcinogenesis experiment on mouse skin. The percentages of tumor-bearing mice in the groups treated with 100 μg of 7,12-dimethylbenz[α]anthracene (DMBA) followed by 5 μg of dinophysistoxin-1, twice a week, and with DMBA followed by 5 μg of okadaic acid twice a week were 86.7% and 80.0% in week 30, respectively. The average number of tumors per mouse was 4.6 in the former group and 3.9 in the latter. Dinophysistoxin-1 and okadaic acid act on cells through different pathways from the 12-O-tetradecanoylphorbol-13-acetate-type tumor promoters.     

Dominant-negative activity of a Brca1 truncation mutant: effects on proliferation, tumorigenicity in vivo, and chemosensitivity in a mouse ovarian cancer cell line

In order to generate an in vitro mouse model for the study of human ovarian cancers, we compared the effects of a truncated Brca1 mutant expression on cellular phenotype with those of a full-length sense and antisense Brca1 expression in the ID-8 mouse epithelial ovarian cancer cell line. The examined cellular processes include proliferation, tumorigenicity in syngeneic mice in vivo and sensitivity/resistance to several cytotoxic drugs. We found that the expression of a spontaneous truncated Brca1 mutant in ID-8 cells which contain two endogenous wild-type Brca1 alleles led to a dominant-negative effect of Brca1, demonstrated by an increase in tumorigenicity in vivo and in chemosensitivity. Expression of a truncated Brca1 mutant in a mouse epithelial ovarian cancer cell line could thus provide a powerful in vitro model for the study of human BRCA1-related ovarian tumorigenesis.     

Aberrant CYP1A1 Induction: Discrepancy of CYP1A1 mRNA and Aryl Hydrocarbon Hydroxylase Activity in Mutant Cells of Mouse Hepatoma Line, Hepa-1

We have isolated new benzo[α]pyrene-resistant clones, cl-21 and cl-32, of the mouse hepatoma line, Hepa-1. CYP1A1-dependent aryl hydrocarbon hydroxylase activity is not inducible by 2,3,7,8-tetrachlorodibenzo- p -dioxin or 3-methylcholanthrene in these two cell lines. However, mRNA of CYP1A1 is inducible in cl-21 and cl-32 cells, as in the wild-type cells, in spite of an undetectable level of cytosolic Ah receptor. The cl-21 cDNA of Cypla-1 was found to have a single mutation leading to an amino acid substitution from Leu (118) to Arg (118). However, the CYP1A1 protein band was not detected on Western immunoblots. The cDNA of cl-32 was found to have a single mutation leading to an amino acid change from Arg (359) to Trp (359). The presence of the mature protein in cl-32 was confirmed by Western blot analysis. Somatic cell hybridization experiments demonstrated that the phenotype of cl-21 and cl-32 is recessive and that these clones belong to the same complementation group. These data suggest that there may be a non-Ah receptor-mediated mechanism of CYP1A1 induction.     

Great potential of a panel of multiple hMTH1, SPD, ITGA11 and COL11A1 markers for diagnosis of patients with non-small cell lung cancer

Research on molecular mechanisms underlying the carcinogenesis of non-small cell lung cancer (NSCLC) may provide gene targets in critical pathways valuable for improving the efficacy of therapy and survival of patients with NSCLC. However, the molecular markers highly sensitive for the prognosis and treatment evaluation of NSCLC are not yet available. To explore candidates, we conducted an oligonucleotide microarray study with three pairs of NSCLC and normal lung tissue, and determined 8 differentially expressed genes including the Human MutT homologue (hMTH1), Surfactant protein D (SPD), Human hyaluronan binding protein 2 (HABP2), Crystalline-mu (CRYM), Ceruloplasmin (CP), Integrin alpha-11 subunit (ITGA11), Collagen type XI alpha I (COL11A1), and Lung-specific X protein (Lun X). Four lung cancer-related markers MUC-1, hTERT, hnRNP B1, and CK-19 were also incorporated for further analysis. The expression profiles of the twelve genes in seventy pairs of NSCLC tumor and normal lung tissue were then detected quantitatively by using membrane array and quantitative real-time PCR (qRT-PCR). The data of the membrane array and qRT-PCR were compared for consistency and the potential of these mRNA markers in clinical application. The results showed that membrane array and qRT-PCR obtained consistent data for the tested genes in both sensitivity and specificity (correlation coefficient 0.921, p<0.0001). For patients' clinicopathological characteristics, the overexpression of hMTH1, SPD, HABP 2, ITGA11, COL11A1, and CK-19 was significantly correlated with the pathological stage (p<0.05). In addition, the overexpression of hMTH1, SPD, ITGA11, and COL11A1 was correlated with lymph node metastasis and poor prognosis. This is the first report relating SPD to a prognosis marker for NSCLC. Moreover, the combined detection of these four mRNA markers by membrane array had a sensitivity of 89% and a specificity of 84% for NSCLC, significantly higher than these markers had achieved separately. In conclusion, we identified mRNA markers for NSCLC prognosis and therapy evaluation from differentially expressed genes determined by using micro-array. Further studies are needed to collect the data of the mRNA markers used in clinical practice.     

Antitumorigenic Effects of Tamoxifen,Raloxifene and the Combination on the Development of Breast Tumors Induced by Mouse Mammary Carcinoma Cells in Balb/c-J Female Mice

Abstract

The antitumorigenic efficacy of tamoxifen, raloxifene, and their combination was evaluated on 4t1 estrogen-positive murine mammary carcinoma cells by determining their ability in breast tumor development in Balb/c-J female mice. Each mouse received intraperitoneally 0.1 ml of PBS solvent containing no drug, 12 mg (0.6 mg/kg) of tamoxifen, 36 mg (1.8 mg/kg) of raloxifene, or the combination of the two drugs (12 mg tamoxifen + 36 mg raloxifene) at 48-hour intervals for 35 days. Drug concentrations used were equivalent to human doses. Within the study period of 35 days, tamoxifen demonstrated the greatest effectiveness, as it allowed “progression-free survival,” increased mouse life span by an average of 6 days, had the greatest number of survivors (90.9%), and those with the smallest spleen weight and volume. Raloxifene and combination groups, compared to the drug-untreated mice, did not significantly lengthen the life span or survivability, produced grossly enlarged spleens, and mice exhibited maladies such as leg paralysis and acute lethargy.     

Concentration-dependent effects of N1, N11-diethylnorspermine on melanoma cell proliferation

N1, N11-diethylnorspermine (DENSPM) is a polyamine analog that is currently under investigation as a novel anticancer drug. Although it has shown promising preclinical activity, there has been large variation in responsiveness reported between different human cancers. During our studies into the causes of this variation, we observed a consistent increase in cell proliferation at low drug concentrations (<10 microM) in human melanoma cells resistant to the drug. At higher concentrations, growth inhibition was seen in all cell lines, with IC50 values ranging 2-180 microM. We hypothesized that DENSPM may mimic endogenous polyamines at low concentrations, supporting cell growth in resistant lines. We also observed that DENSPM downregulated polyamine transport in a manner similar to that for spermidine, a finding that confirms previous reports. Finally, DENSPM could rescue cells from growth arrest by the ornithine decarboxylase inhibitor difluoromethylornithine, which depletes intracellular polyamines. Taken together, these results suggest that DENSPM, at clinically relevant concentrations, can mimic endogenous polyamines and induce proliferation in resistant human melanoma cells.     

Discrimination of Cancer Stem Cell Markers ALDH1A1, BCL11B,BMI-1, and CD44 in Different Tissues of HNSCC Patients

Cancer stem cells (CSCs) are accountable for the progress of head and neck squamous cell carcinoma (HNSCC). This exploratory study evaluated the expression of molecular CSC markers in different tissues of HNSCC patients. Tissue specimens of primary tumor, lymph node metastases and macroscopically healthy mucosa of 12 consecutive HNSCC patients, that were treated with surgery and adjuvant radio(chemo)therapy upon indication, were collected. Samples were assessed for the expression of p16 as a surrogate for HPV-related disease and different molecular stem cell markers (ALDH1A1, BCL11B, BMI-1, and CD44). In the cohort, seven patients had HPV-related HNSCC; six thereof were oropharyngeal squamous cell carcinoma. While expression of BMI-1 and BCL11B was significantly lower in healthy mucosa than both tumor and lymph node metastasis, there were no differences between tumor and lymph node metastasis. In the HPV-positive sub-cohort, these differences remained significant for BMI-1. However, no significant differences in these three tissues were found for ALDH1A1 and CD44. In conclusion, this exploratory study shows that CSC markers BMI-1 and BCL11B discriminate between healthy and cancerous tissue, whereas ALDH1A1 and CD44 were expressed to a comparable extent in healthy mucosa and cancerous tissues.     

A pilot study on the safety of combining chrysin, a non-absorbable inducer of UGT1A1, and irinotecan (CPT-11) to treat metastatic colorectal cancer

Purpose: Recently, it was shown that chrysin causes upregulation of UGT1A1 in Caco-2 intestinal cells. Therefore, we proposed that oral chrysin may reduce irinotecan (CPT-11) induced diarrhoea by shifting the SN-38G/SN-38 equilibrium towards the inactive SN-38G in the gastrointestinal mucosa. The purpose of this study was to examine the safety of combining single agent CPT-11 with chrysin. Patients and methods: Twenty patients with previously treated advanced colorectal cancer were administered chrysin twice daily for 1 week preceding and succeeding treatment with single agent CPT-11 (350 mg/m² over 90 min every 3 weeks). Loperamide usage and bowel frequency/consistency were recorded by patients into a study diary and blood samples were collected for CPT-11 pharmacokinetic analysis. Results: There were no observable toxicities that could be attributed to chrysin use. The grades and frequency of delayed diarrhoea were mild, with only 10% of patients experiencing grade 3 toxicity. Loperamide usage was also modest with a median of 1–5 tablets per cycle (range: 0–22). Pharmacokinetic results revealed a mass ratio of plasma SN-38G/SN-38, which was very similar to historical controls (7.15±5.67, n=18). Conclusions: These findings, combined with the observation of clinical activity and grade 3/4 neutropenia in 25% of patients, suggest that combining chrysin with CPT-11 may be a safe and potentially useful means of preventing diarrhoea, although this needs to be further investigated in the setting of a randomised trial.     

Loss of heterozygosity on chromosomes 1, 11, 12, and 14 in hybrid mouse lung adenocarcinomas

An allelotype analysis of lung tumors in mouse hybrids was conducted to identify common regions of allelic loss. By using 50 informative genetic markers, the autosomes of 36 (A/J x C3H/HeJ) F₁ adenocarcinomas were examined. Additional adenocarcinomas from as many as 72 (C3H/HeJ x A/J) F₁ and 15 (BALB/cJ x DBA/2J) F₁ hybrids also were analyzed for DNA loss at some of the loci. Loss of heterozygosity (LOH) was observed at multiple loci and occurred with the most regularity at markers on chromosomes 12 (28%), 14 (28%), 11 (21%), and 1 (20%). The frequency of LOH was not greater than 11% on any of the other chromosomes. Chromosomes 11 and 14 often displayed allelic loss at markers located near the p53 and retinoblastoma tumor suppressor loci, respectively. LOH at markers on chromosomes 12 and 14 was associated with tumors having overall frequencies of allelic loss that exceeded the median value. Losses on chromosomes 1, 11, 12, and 14 also showed a significant association with the adenocarcinoma stage of mouse lung tumorigenesis, suggesting that the inactivation of tumor suppressor loci on these chromosomes may participate in the progression of these tumors. © 1996 Wiley-Liss, Inc.     

Erythropoietin in radiation oncology - A review. 1st international conference, Freiburg, June 11-12, 1999

The therapeutic potential of erythropoietin gains increasing attention among radiation oncologists because the prognosis is better for patients with high blood hemoglobin levels following radiotherapy. However, there is still a debate on how hemoglobin affects radiotherapy. Further, the means to manipulate the hemoglobin level, their indication and administration need to be clarified. Available experimental and clinical data on hypoxia, anemia and on their treatment with erythropoietin have been extensively discussed at an international conference in Freiburg, Germany, in June 1999. This report gives a summary reviewing the topic.     

Characterization of a novel mouse monoclonal antibody, clone 1E8.33, highly specific for human procollagen 11A1, a tumor-associated stromal component

A novel IgG1, κ mouse monoclonal antibody (clone 1E8.33) to human procollagen 11A1 has been generated. This antibody is poorly mutated, essentially in germ line configuration; its complementarity determining regions (CDRs) are especially rich in tyrosine and serine residues. The epitope recognized is encompassed in the YNYGTMESYQTEAPR amino acid stretch within the variable region of human procollagen 11A1. Human procollagens 5A1 and 11A1 are very similar. However, this antibody does not cross-react with human procollagen 5A1. In human breast tumors, only the activated peritumoral myofibroblasts show a strong intracytoplasmic staining with this antibody. As procollagen 11A1 is overexpressed in the stroma of human tumors with desmoplastic reaction, this antibody represents a valuable tool for diagnostic purposes.