bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxia‐induced resistance to doxorubicin and methotrexate in human melanoma cell lines in vitro
Authors: Sanna Kirsten , Rofstad Einar K.
Published: February 2007

Rodent cell lines can develop resistance to doxorubicin and methotrexate during hypoxic stress. This has so far not been observed in human tumor cell lines. The purpose of our communication is to show that doxorubicin and methotrexate resistance can also develop in human melanoma cells during exposure to hypoxia. Four cell lines (BEX‐c, COX‐c, SAX‐c, WIX‐c) have been studied. Cells were exposed to hypoxia (O2 concentration < 10 ppm) for 24 hr prior to reoxygenation. Doxorubicin and methotrexate cell survival curves were determined immediately after as well as 18 and 42 hr after reoxygeation. The 4 cell lines were relatively sensitive to doxorubicin without hypoxia pre‐treatment, and all developed resistance during exposure to hypoxia. Hypoxic stress also induced methotrexate resistance in BEX‐c and SAX‐c but not in COX‐c and WIX‐c. BEX‐c and SAX‐c were sensitive to methotrexate without hypoxia pre‐treatment, whereas COX‐c and WIX‐c were resistant initially. Hypoxia‐induced drug resistance was present immediately after reoxygenation and tended to decrease with time but remained statistically significant even 42 hr after reoxygenation.
Overexpression of p53 protein in betel‐ and tobacco‐related human oral dysplasia and squamous‐cell carcinoma in India
Authors: Kaur Jasbir , Srivastava Anurag , Ralhan Ranju
Published: February 2007

The aetiological factors for oral cancer are not the same in India and in Western countries. Epidemiological studies have shown a correlation between high incidence of oral cancer and heavy consumption of betel and/or tobacco in the Indian population, while this stud/ indicates an association with a genetic change. The p53 tumour‐suppressor gene is the most commonly identified mutated gene in human malignancies. Expression of p53 protein was examined in premalignant and malignant oral lesions from Indian patients who were consumers of betel, areca nut and/or tobacco, using anti‐p53 monoclonal antibodies PAb 1801 and PAb 421. Cryosections from normal, premalignant or malignant oral mucosa were used for immunostaining and the observations were confirmed by immunoprecipitation. P53 protein was detected in 55% (15/27) premalignant oral lesions (leukoplakia). Strong p53‐positive staining was detected in 75% (24/32) of oral squamous‐cell carcinomas. Normal oral mucosa did not show positive p53 staining (0/24). The detection of p53 protein in premalignant oral lesions suggests that p53 aberrations are an early event in the development of oral cancer in India. The high incidence of p53 positivity in leukoplakia may be due to differences in aetiological factors. p53 overexpression in premalignant oral lesions is important in view of the significantly earlier onset of leukoplakia in the Indian population compared to the development of oral malignancy, and may be helpful in identifying lesions that are more likely to progress to malignancy. The frequency of p53 protein overexpression was high in premalignant and malignant oral lesions of patients who were heavy consumers of betel, areca nut and tobacco.
A new cancer‐associated antigen defined by a monoclonal antibody against a synthetic carbohydrate chain
Authors: Yamashita Yoshito , Chung Yong Suk , Sawada Tetsuji , Kondo Yasuyuki , Hirayama Koji , Inui Akimasa , Nakata Bunzo , Okuno Masahiro , Horie Ryuichi , Saito Takashi , Murayama Keiichi , Kannagi Reiji , Sowa Michio
Published: February 2007

Carbohydrate antigens can be designed by referring to previously defined carbohydrate structures. We have generated a novel monoclonal antibody (MAb) (Flα‐75) against an artificially designed antigen (Flα), using organic‐synthetic chemistry methods and hybridoma technology. Flα (GalβI → 4GlcNAcβI → 6GalNAαI → Ser/Thr) belongs to core type 6 of O‐linked glycans, which has not been previously reported in human cancers. To produce antibodies against Flα, a glycolipid was synthesized which carries the carbohydrate portion of Flα on a ceramide foundation (GalβI → 4GlcNAcβI → 6GalNAcαI → Cer). The MAbs we obtained (Flα‐75, Flα‐87) specifically recognized Flα and had only a very weak or no cross‐reactivity with other glycolipids similar to Flα. We investigated the expression of Fin in human tissues, including 110 gastric cancers, 73 colon cancers and 42 pancreatic cancers. Flα was found in human cancerous tissues but not in normal adult tissues. The rate of positive staining with Flα‐75 was 80.0% for gastric cancer, 52.4% for pancreatic cancer and 38.4% for colon cancer. Flα‐75 also reacted with the tissues neighboring gastric and pancreatic tumors but not intensely. Among fetal tissues, Flα‐75 reacted with the pyloric glands of the stomach, the centro‐acinar cells of the pancreas, the convoluted tubules of the kidney and the terminal bronchioles of the lung.
Fibroblast activation protein: Purification, epitope mapping and induction by growth factors
Authors: Rettig Wolfgang J. , Su Sai L. , Fortunato Sheila R. , Scanlan Matthew J. , Mohan Raj B. K. , Garin‐Chesa Pilar , Healey John H. , Old Lloyd J.
Published: February 2007

The human fibroblast activation protein (FAP) defined by monoclonal antibody (MAb) F19 is a cell surface antigen expressed in reactive stromal fibroblasts of breast, colorectal, lung and other epithelial cancers. In contrast to its stroma‐specific localization in epithelial neoplasms, FAP is expressed in the malignant mesenchymal cells of bone and soft‐tissue sarcomas. FAP is transiently expressed in some fetal mesenchymal tissues but is absent or expressed at low levels in most adult tissues. FAP is induced in cultured fibroblasts and, in these cells, consists of a Mr 95,000 subunit (FAPα) carrying the F19 epitope and a non‐covalently bound Mr 105,000 subunit (FAPβ) lacking the F19 epitope. Using MAb F19 and 5 newly derived MAbs, we identify 3 distinct epitopes on FAPα and tentatively assign one epitope to FAPβ. Analysis of detergent extracts of a FAPαhighβ‐sarcoma cell line by size exclusion–high performance liquid chromatography (HPLC) revealed that FAPα does not elute as a Mr, 95,000 species but as part of a high‐molecular weight complex (Mr > 400,000) that dissociates into Mr 95,000 subunits in SDS gels. Immunoaffinity purification of FAPα followed by tryptic digestion, reversed‐phase HPLC and microsequencing identified 3 unique FAPα peptides, with 2 showing sequence similarity (23/38 identical amino acids) to segments of CD26, a T‐cell activation antigen. CD26 is a membrane‐bound enzyme (dipeptidyl aminopeptidase IV), but immunopurified FAPα has little if any dipeptidase activity with typical CD26 substrates. Finally, studies with FAPlow leptomeningeal fibroblasts revealed that transforming growth factor‐β, 12‐O‐tetradecanoyl phorbol‐13‐acetate and retinoids can upregulate FAP expression, whereas serum and several other factors had no or little effect on FAP levels. FAP and CD26 may belong to a family of structurally related but functionally distinct activation proteins that are expressed on different cell types and show unique modes of regulation in normal and malignant cells.
Therapeutic effect of adriamycin encapsulated in long‐circulating liposomes on meth‐a‐sarcoma‐bearing mice
Authors: Oku Naoto , Doi Kanako , Namba Yukihiro , Okada Shoji
Published: February 2007

Long‐circulating liposomes modified with a uronic‐acid derivative, palmityl‐D‐glucuronide (PGIcUA), have been developed previously for the passive targeting of liposomes to tumor tissues. In this study, we examined the therapeutic effect of adriamycin (ADM) encapsulated in PGIcUA liposomes composed of dipalmitoylphosphatidylcholine (DPPC), cholesterol (Chol) and PGIcUA (molar ratio, 40/40/10) since this amount of PGIcUA was enough to endow liposomes with long‐circulating activity. Long‐circulating activity was also observed with palmityl‐D‐galacturonide (PGalUA) modified liposomes, suggesting that uronic acid plays an important role in preventing liposomes from being trapped in the reticuloendothelial system (RES). ADM was loaded in liposomes by a remote‐loading method. Free or liposomal ADM was injected i.v. into BALB/c mice bearing s.c.‐implanted Meth‐A sarcoma. The liposomal formulation was efficient for reducing tumors, prolonging survival time and curing the animals, especially in the case of large tumors where free ADM was not. Furthermore, PGIcUA liposomes were more effective than conventional liposomes containing dipalmitoylphosphatidylglycerol (DPPG) instead of PGIcUA for prolonging survival time in mire. It might therefore be appropriate to use PGIcUA liposomes as the carriers of anticancer drugs.
Therapeutic effects of D‐aspartic acid β‐hydroxamate (DAH) on friend erythroleukemia
Authors: Tournaire Roselyne , Malley Serge , Hamedi‐Sangsari Farid , Thomasset Nicole , Grange Jacques , Dore Jean François , Vila Jorge
Published: February 2007

D‐aspartic acid β‐hydroxamate (DAH), an aspartic acid analogue, exerts anti‐tumoral activity against murine leukemia L5178Y bath in vitro and in vivo. We show here that DAH displays activity against Friend leukemia cells (FIX) in vitro: a concentration of 2 mM results in a total inhibition of cell growth. DAH is also active in vivo against Friend virus (FV‐P)‐induced erythroleukemia. Treatment with DAH, given for 95 days as a single daily i.p. injection to DBA/2 mice 3 days following FV‐P inoculation, induced a marked increase of 212% in the mean survival time (MST) of treated animals. Since FV‐P‐induced erythroleukemia is characterized by the proliferation of mature erythroid precursors, we examined the effect of DAH treatment on erythroid colony‐forming cells (CFU‐E) and observed that the number of CFU‐E per spleen was 30 times lower in DAH treated mice than in the controls. To gain further insight into the early effects of DAH treatment on the early phase of Friend disease, we examined the effects of short DAH treatment on spleen size, hematocrit and viremia in FV‐P‐infected mice. DAH treatment initiated 3 days post infection (p.i.) inhibited splenomegaly, prevented virus‐induced polycythemia, and reduced serum viremia. Late DAH treatment (18 days p.i.) induced regression of FVP‐induced disease as evidenced by reduction of spleen weight.
Effect of the nonsteroidal antiestrogen ZK 119.010 on growth and metastasis of the EnDa endometrial carcinoma
Authors: Horn Daniel W. , Vollmer Günter , Angerer Erwin Von , Schneider Martin R.
Published: February 2007

For patients with disseminated endometrial cancer the prognosis is poor. Radiotherapy, chemotherapy or high‐dose progestins have been of limited value in the clinic, with low response rates and a usually short duration. Because of the role of estrogen in the etiology of this disease, a rationale exists for therapies using estrogen antagonists. In order to test this strategy, we used the EnDA endometrial carcinoma of the rat recently described by us. The nonsteroidal antiestrogen ZK 119.010 inhibited the primary‐tumor growth of the s.c. implanted EnDA endometrial carcinoma by 50%, being superior to high‐dose progestin and tamoxifen (TAM). Moreover, in intact as well as in castrated estrogen (E2)‐substituted rats, ZK 119.010 substantially reduced metastatick‐tumor growth in the lymph nodes and lungs. With TAM, however, the number of lung metastases in intact and in castrated E2‐substituted rats either rose or remained stable and the weight of lymph nodes in intact rats increased. After TAM treatment, almost no low‐salt‐extractable (cytosolic) estrogen receptor (ER) was measurable in the tumor, whereas ZK 119.010 did not alter ER concentrations. The stimulation of metastatic tumor growth, as well as the loss of cytosolic ER under TAM therapy, may reflect the well‐known agonist activity of this compound in uterine tissues. ZK 119.010, however, not only lacks this agonist activity, but it exerts a strong antagonistic one. In conclusion, pure antiestrogens may help to improve treatment of endometrial cancer.
Risk assessment of tobacco, alcohol and diet in oral cancer—A case‐control study
Authors: Rao D. N. , Ganesh B. , Rao R. S. , Desai P. B.
Published: February 2007

A retrospective case‐control study of 713 male oral‐cancer patients seen at Tata Memorial Hospital, Bombay, during 1980‐1984 was undertaken to assess the association between chewing, smoking and alcohol habits. Male controls were chosen among those persons who attended the hospital during the same period and were diagnosed as free from cancer, benign tumour and infectious disease. Statistical analysis was based on unconditional logistic regression and the confidence interval for RR was calculated using the standard error of the estimates. Established factors such as tobacco chewing and bidi smoking showed a significant association with oral cancer. For the alcohol habit, the relative risk was 1.42 and the dose‐response relationship, in terms of frequency and duration of the habit, was also observed. The illiterate group showed an almost 2‐fold significant excess risk compared to the literate group. After adjusting for confounding variables such as age, residence, illiteracy and known factors such as tobacco chewing and bidi smoking, the study has brought out the significance of a non‐vegetarian diet as a high‐risk factor for oral cancer compared to a vegetarian diet. Further studies are required to identify specific items in the non‐vegetarian diet which may be associated with oral cancer.
Expression of the co‐stimulatory molecule B7 on melanoma cells
Authors: Hersey Peter , Si Zhaoyi , Smith Melanie J. , Thomas Wayne D.
Published: February 2007

The induction of T‐cell responses against tumor cells is believed to depend on both recognition of antigen and receipt of co‐stimulatory signals from interaction of ligands such as B7 with its receptors CD28 or CTLA‐4 on T cells. In the present study the expression of B7 on cultured human melanoma cells was studied at the mRNA level by reverse PCR analysis and surface expression by flow cytometric analysis with monoclonal antibodies (MAbs). PCR analysis revealed mRNA for B7 in 3 of 6 (50%) cultured primary melanoma and 8 of 19 (42%) cultures of metastatic melanoma. Analysis of B7 expression by flow cytometry using the BBI MAb revealed low levels of expression in 3 of 10 melanoma that had mRNA for B7. In 2 of the latter (but not 4 other PCR+ lines) expression could be increased by culture in GM‐CSF, IL‐2, IFN‐γ and IFN‐α2. Our results indicate that although mRNA for B7 is present in 40‐50% of melanoma cell lines, expression at the protein level is at low or undetectable levels in the majority of the cell lines. Expression of B7 protein was also not detected in studies on tissue sections from 11 primary and 9 metastatic melanomas.
Ornithine decarboxylase inhibitor attenuates bombesin enhancement of intestinal carcinogenesis and metastasis induced by azoxymethane
Authors: Iishi Hiroyasu , Tatsuta Masaharu , Baba Miyako , Uehara Hiroyuki , Nakaizumi Akihiko
Published: February 2007

The effects of combined administration of bombesin (40 μ/kg body weight) and the ornithine decarboxylase (ODC) inhibitor, 1,3‐diaminopropane (DAP), on the development of large and small intestinal tumors and the incidence of their metastasis to the peritoneum induced by azoxymethane (AOM, 7.4 mg/kg body weight), the ODC activity of the intestinal wall, and the labeling index of the intestinal mucosa and tumor were investigated in inbred Wistar rats. Rats received weekly s.c. injections of AOM for 10 weeks, s.c. injections of bombesin every other day, and drinking water containing DAP (2.5 g/l) until the end of the experiment at week 40. Administration of bombesin significantly increased the incidence of intestinal tumors at week 40. It had no influence on the location, size, histological features or depth of involvement of intestinal adenocarcinomas, but significantly increased the incidence of their metastasis to the peritoneum. It also resulted in a significant increase in the intestinal ODC activity and labeling index. Administration of DAP with bombesin significantly reduced the enhancement of intestinal carcinogenesis by bombesin. Although the combined use of DAP with bombesin had little or no influence on the location, size, histological features, or depth of involvement of intestinal cancers, the incidence of their metastasis was significantly reduced. DAP significantly attenuated bombesin enhancement of the intestinal ODC activity and labeling index. These findings indicate that ODC inhibition attenuated the enhancement of intestinal carcinogenesis and metastasis to the peritoneum.
Modulation of Mr 72,000 and Mr 92,000 type‐IV collagenase (gelatinase A and B) gene expression by interferons alpha and gamma in human melanoma
Authors: Hujanen Erkki S. , Väisänen Anne , Zheng Aiping , Trygdvason Karl , Turpeenniemi‐Hujanen Taina
Published: February 2007

The purpose of this study was to determine how interferons α and γ influence the expression of Mr 72,000 type‐IV collagenase (gelatinase A) and Mr 92,000 type‐VI collagenase (gelatinase B) genes and whether there are differences in their gene expression. Special emphasis was focused on the treatment time. Total cellular RNA from A2058 human melanoma cells treated for various time periods with IFN‐α or γ was analyzed by Northern‐and slot‐blot hybridization. Both Mr 72,000 and Mr 92,000 type‐IV collagenase mRNAs were detectable in A2058 cells and mRNA levels for both gelatinases were significantly up‐regulated in the cells treated for a short time period with either IFN‐α or γ. In contrast, a long‐term treatment (7 days) with these drugs markedly down‐regulated the genes for both gelatinase A and B. Zymographic analysis showed that human melanoma primarily secretes the gelatinase‐A activity, which showed changes similar to those seen in the corresponding mRNA after the treatments with interferons. The expression of gelatinase‐B activity was, however, detectable only transiently during the stimulating phase with IFN‐α. Western immunoblot analysis showed that alterations in the levels of immunoreactive protein of gelatinase A in the cells correlated with the mRNA levels after the treatments. These findings suggest that IFN‐α and IFN‐γ are potent regulators of both Mr 72,000 and Mr 92,000 type‐IV collagenase/gelatinase A and B genes in human melanoma showing biphasic and parallel effects on mRNA levels of both enzymes, depending on the treatment time, and that the Mr 72,000 metalloproteinase/gelatinase A is the predominant basement‐membrane‐degrading type‐IV collagenase in human melanoma.
Establishment of hormone‐dependent and hormone‐indhpendent carcinoma cell lines with different metastatic potentials from spontaneous mammary tumors in aged wistar rats
Authors: Nakanishi Hayao , Taylor Robert M. , Hawkins Anita L. , Griffin Constance A. , Martin George R. , Passaniti Antonino
Published: February 2007

Three stable carcinoma cell lines, designated RM22‐F5, RM17 5R, and RM 1‐4, were established from spontaneously occurring mammary carcinomas in old, outbred, female Wistar rats. The RM22‐F5 and RM 17‐SR cells were keratin‐positive and formed epithelial monolayers, whereas RMI‐4 cells exhibited a spindle‐like morphology and intense vimentin staining. When injected into nude mice, RM22‐F5, RM17‐5R and RM1‐4 cells formed well‐differentiated, poorly differentiated and undifferentiated carcinomas, respectively. The relative growth rates of the tumor cells in vitro were RM1‐4 > RM22‐F5 > RM17‐5R. The growth of RM22‐F5, but not of RM17‐5R and RM1‐4 cells, was significantly stimulated by insulin, epidermal growth factor, dexamethasone, 17β‐estradiol and progesterone in vitro. Ovariectomy reduced the growth of RM22‐F5 cells in vivo and these cells (but not RM1‐4 or RM17‐5R) were estrogen‐receptor (ER)‐positive. None of the lines were positive for the progesterone receptor (PR). Spontaneous lung and lymph‐node metastases were observed in nude mice injected with RM22‐F5 or RM17‐5R cells, respectively. In contrast, RM1‐4 cells were non‐metastatic but invasive. Karyotype analysis revealed that RM22‐FS cells were hyperdiploid, RM 17‐SR were hypotetraploid, and RM1‐4 were diploid with a sizeable insertion in chromosome I. A point mutation in codon 12 (G to A transition) and loss of the normal aliele of the H‐ras‐1 gene was detected in the DNA from RM22‐FS cells. No p53 mutations were apparent in any of the cell lines. The results indicate that RM22‐F5 cells are hormone‐dependent with an ER+/PR− phenotype, while the RM 17‐SR and RM1‐4 lines are hormone‐independent and ER−/PR. These cell lines exhibit the spectrum of biological properties and genetic alterations observed in human breast cancers and may, therefore, be novel and useful models for understanding sporadic breast cancer in post‐menopausal women.
Hox gene expression in human small‐cell lung cancers xenografted into nude mice
Authors: Tiberio Claudia , Barba Pasquale , Magli Maria Cristina , Arvelo Francisco , Chevalier Thierry Le , Poupon Marie France , Cillo Clemente
Published: February 2007

Transcription factors are crucial to an understanding of the molecular basis of neoplasia. Horneobox‐containing genes are a family of transcriptional regulators encoding DNA‐binding ho‐meodomains, involved in the control of normal development. Class‐1 human homeobox‐containing genes (HOX genes) display a peculiar chromosomal organization, perhaps directly related to their function. Aberrant expression of homeobox‐genes has been associated with both morphological abnormalities and oncogenesis. We have recently observed that alterations in HOX gene expression are detectable in kidney and colon cancer when compared to the corresponding normal organs. Here we have analyzed the expression of HOX genes in primary and metastatic human small‐cell lung cancer (SCLC) xenografted in nude mice, in order to investigate whether HOX gene expression correlates with the histology and stage of SCLC progression. The results show that different SCLCs display differential patterns of HOX gene expression. Furthermore, in SCLC, the number of actively expressed HOX genes might be substantially lower in metastatic cancers than in primary tumors. The alteration in HOX gene expression in SCLCs mainly concerns the HOX B and C loci. This finding suggests that downregulation of HOX genes may play a role in small‐cell lung cancer progression, possibly through their implication in tumor suppression.
Association of c‐erbB2‐gene amplification with poor prognosis in non‐inflammatory breast carcinomas but not in carcinomas of the inflammatory type
Authors: Lě Monique G. , Douc‐Rasy Sétha , Ahomadegbe Jean Charles , Spielmann Marc , Guérin Martine , Riou Guy
Published: February 2007

It is now accepted that c‐crbB2‐gene amplification is correlated with poor clinical outcome for patients, mainly when axillary nodes are invaded. We have confirmed this result by multivariate analysis in 178 patients with non‐inflammatory breast cancer followed up for a mean period of 6.8 years (SD, 1.6 years). In addition, we have shown that c‐erbB2 amplification, found in 30 (17%) specimens, was associated with a high risk of multiple metastases developing simultaneously. In contrast, for the 67 patients with inflammatory breast carcinoma, the most aggressive type of breast carcinoma, the c‐erbB2 amplification detected in 24 (36%) specimens was not found to be associated with a higher risk of death, suggesting that the oerbB2 gene plays a different role in the progression of these 2 types of breast cancer. Furthermore, our data stress the importance of the methodological approach used to determine gene amplification. Although Southern blot hybridization is a tumour‐ and time‐consuming method not easy to adopt in routine clinical practice, this method remains a reference quantitative method.
Effect of recombinant human interferon‐alpha/2b on epidermal‐growth‐factor‐, estrogen‐ and progesterone‐receptor expression in primary cervical cancer
Authors: Scambia Giovanni , Panici Pierluigi Benedetti , Ferrandina Gabriella , Battaglia Francesco , Sica Gigliola , Coronetta Ferdinando , Rumi Carlo , Mancuso Salvatore
Published: February 2007

The effects of a short period of in vivo systemic rh‐IFN‐alpha/2b treatment on epidermal‐growth‐factor(EGFR)‐, estrogen(ER)‐ and progesterone (PR)‐receptor content in 11 primary human cervical tumors was investigated by the radioreceptorial technique. EGFR levels were found to be significantly higher in cervical tumors after rh‐IFN‐alpha/2b treatment with respect to basal levels. In 2 cases, immunohistochemical and cytofluorimetric analysis showed that rh‐IFN‐alpha/2b treatment induces an increase in EGFR immunoreactivity and in the fraction of EGFR‐positive cells. No difference in ER and PR levels in cervical tumors before and after rh‐IFN‐alpha/2b treatment was observed. Our results suggest that rh‐IFN‐alpha/2b up‐regulates EGFR in primary human cervical tumors in vivo.
Expression of neuronal src mRNA as a favorable marker and inverse correlation to N‐myc gene amplification in human neuroblastomas
Authors: Matsunaga Tadashi , Shirasawa Hiroshi , Tanabe Masahiro , Ohnuma Naomi , Kawamura Kenji , Etoh Takao , Takahashi Hideyo , Simizu Bunsiti
Published: February 2007

Neuron‐specific sre mRNA, which is expressed in human brain tissue by alternative splicing, is associated with neural differentiation. Neuronal c‐srcN I expression may be associated with the ability of neu roblastomas to mature; furthermore, c‐srcN2 mRNA is induced in chemically differentiated neuroblastoma cells in vitro. The prognosis of a patient with a neuroblastoma is strongly affected by the ability of the tumor to differentiate in vivo. In order to clarify the relationship between neuronat src mRNA expression and the clinical outcome of a neuroblastoma, we analyzed the expression of src mRNA in neuroblastoma tissues from 28 patients by SI‐nuc I ease‐protection assay. N‐myc gene amplification was also examined by Southern blot hybridization. The clinical significance of neuronal src mRNA expression and its relevance to N‐myc gene amplification was also investigated. A high ratio (more than 10%) of c‐srcN2 mRNA expression was observed in all early‐stage tumors and in advanced neuroblastomas with a favorable prognosis. In contrast, in advanced neuroblastomas with an aggressive clinical phenotype, c‐srcN2 mRNA expression was found at a low ratio (below 10%). Genomic amplification of the N‐myc gene and expression of c‐srcN2 mRNAs were inversely correlated. When combined with other prognostic markers such as N‐myc gene amplification, the expression of c‐srcN2 mRNA may be a new biological marker to predict the prognosis of patients with neuroblastomas.
Prevalence of deletions of YY1‐binding sites in episomal HPV 16 DNA from cervical cancers
Authors: Dong Xiao‐Ping , Stubenrauch Frank , Beyer‐Finkler Elke , Pfister Herbert
Published: February 2007

Expression of the oncogenes E6 and E7 of human papillomavirus 16 (HPV 16) appears enhanced in pre‐malignant and malignant genital tumors. We recently identified a transcriptional silencer upstream of the oncogene promoter P97, comprising 4 binding sites for the cellular YYI protein. The analysis of the long transcriptional control regions (LCR) of episomal HPV 16 DNAs from primary tumors and lymph‐rode metastases of 6 patients with cervical cancer revealed deletions and point mutations of YYI binding sites in 4 cases. To test for the activity of the P97 promoter, the mutated LCRs were cloned in a tuciferase reporter gene vector. A point mutation in YYI‐recognition site 4, which prevents DNA‐protein interaction, did not affect promoter activity, probably due to compensation by the overlapping YYI‐binding site 3. However, 5.S‐ to 6.5‐fold increased luciferase expression was obtained under the control of 3 shortened LCRs lacking 2 to A YYI‐binding sites. A point mutation in YYI‐recognition site 2, which was previously shown to stimulate P97 3.5‐fold, could be detected in the HPV 16 LCRs from both primary tumor and metastasis, indicating that the mutation is a stable characteristic of HPV 16 DNA associated with the individual cancer. These findings suggest that deletions or mutations of YYI‐binding sites play a significant role in over‐expression of viral oncogenes and tumor progression.
Differentiation ability and oncogenic potential of HPV‐33‐and HPV‐33+ras‐transfected keratinocytes
Authors: Gilles Christine , Piette Jacques , Peter Wolfgang , Fusenig Norbert E. , Foidart Jean‐Michel
Published: February 2007

Five HPV‐33‐immortalized and 5 HPV‐33+ras‐transfected cell lines were characterized in terms of growth in soft agar, tumorigenic potential in nude mice, p2l expression, morphology and expression of differentiation markers in organotypic cultures. No striking differences were observed between the HPV‐33‐immortalized cell lines and their corresponding ras‐transfected counterparts as regards their tumorigenicity in nude mice (only one cell line was able to develop tumors in nude mice) or their behavior on lifted collagen gels. However, all the ros‐transfected cell lines gave rise to colonies in soft agar while only 2 HPV‐33‐transfected lines (CK1 and CK4) displayed this property. The 10 cell lines could be divided into 2 groups with respect to their phenotype in monolayer and in organotypic cultures. Lines from group 1 (CK1,3, 5 and their ras‐transfected homologous lines) shared a typical epithelial phenotype in monolayer and the ability (a) to form an epithelium similar to a CIN‐III lesion and (b) to strongly express keratins KI‐KIO and involucrin in organotypic cultures. On the other hand, for the lines from group II (CKI, CK4, CKI EJ7 and CK4EJ5), there was a correlation between an elongated phenotype in monolayer and the property (a) to form a structure similar to a microinvasive carcinoma and (b) to express vimentin and keratins K‐KI8. These cell lines, exhibiting various transformation‐associated alterations, can be considered as an in vitro model representing various stages of HPV‐33‐associated cervical carcinogenesis.
The human zinc‐finger protein‐7 gene is located 90 kb 3′ of MYC and is not expressed in Burkitt lymphoma cell lines
Authors: Gallego Marta I. , Lazo Pedro A.
Published: February 2007

The zinc‐finger gene‐7 (ZNFT) was located 90 kb 3′ of MYC on human chromosome 8 band q24 by pulsed‐field gel electropho‐resis (PFGE). This position lies between the MLV14 and BVRI loci, 2 variant translocation breakpoints in Burkrtt tymphomas. The structure of the ZNF7 gene was not altered by translocations in Burkitt‐lymphoma cell lines as shown by its germline‐restriction map configuration. The chromosomal region surrounding the ZNF7 gene was extensively methylated. The ZNF7 gene was not expressed in 19 BL cell lines. Expression was detected only in the BL41 and BL47 cell lines and in the SW756 cervical‐carcinoma cell line. The UNA in each was of a different size. We postulate that the lack of ZNF7 expression in Burkitt lymphomas might contribute to the tumor phenotype.
A cleaved form of the receptor for urokinase‐type plasminogen activator in invasive transplanted human and murine tumors
Authors: Solberg Helene , Rømer John , Brünner Nils , Holm Arne , Sidenius Nicolai , Danø Keld , Høyer‐Hansen Gunilla
Published: February 2007

It was recently found that urokinase‐type plasminogen activator (uPA) is involved in the cleavage of its receptor (uPAR) on cultured cells, thereby releasing one of the receptor's 3 domains (the ligand binding domain I) and leaving the 2 others [uPAR(2 + 3)] anchored to the cell surface. With monoclonal antibodies (MAbs) we have now identified human uPAR(2 + 3) in lysates of invasive human MDA‐MB‐231 mammary carcinomas xenografted into nude mice. The production of peptide antibodies recognizing different domains of murine uPAR made it possible to identify a similar cleaved form of uPAR, murine uPAR(2 + 3), in extracts of primary Lewis lung carcinomas. Cleavage of uPAR also occurs in cultured MDA‐MB‐231 cells and Lewis lung carcinoma cells. This cleavage is inhibited by anticatalytic antibodies to either human or murine uPA, respectively, indicating that it is catalyzed by either uPA or plasmin generated by uPA. The amount of uPAR(2 + 3) may therefore be directly related to the activity of the uPA system and it is possible that the level of uPAR(2 + 3) in cancer tissue may prove to be a stronger prognostic parameter than the levels of either full‐length uPAR or UPA.
bcl‐2 expression in normal breast tissue during the menstrual cycle
Authors: Sabourin J. C. , Martin A. , Baruch J. , Truc J. B. , Gompel A. , Poitout P.
Published: February 2007

bcl‐2 is a proto‐oncogene discovered through the t(14; 18) translocation occurring in most human follicular lymphomas. The function so far attributed to bcl‐2 is to counteract the occurrence of apoptosis and to prolong cell survival without affecting the cycling cells. Apoptosis has been described in normal breast tissue epithelial cells, and it peaks at the end of the luteal phase. We have studied bcl‐2 expression by an immunohistochemical method in 50 samples of normal breast tissue distributed throughout the menstrual cycle. bcl‐2 staining predominated in the lobular epithelial cells. It displayed a striking cyclic variation, with maximal expression at the midcycle period and a sharp decrease at the end of the cycle. These results strongly suggest that the regulation of bcl‐2 expression in breast tissue is hormone‐dependent. This could be of significance in tumorigenesis.
Phenotypic heterogeneity in breast fibroblasts: Functional anomaly in fibroblasts from histologically normal tissue adjacent to carcinoma
Authors: Schor Ana M. , Rushton Graham , Ferguson Janice E. , Howell Anthony , Redford Judy , Schor Seth L.
Published: February 2007

Histologically normal breast tissue was obtained from women undergoing surgery for benign breast lesions (n = 12) and mammary carcinomas (n = 15). Four fibroblast subpopulations (FI, FII, FIII and FIV) were isolated from these specimens by differential digestion and centrifugation. FI cells were the first to be released from the tissue digest and consequently assumed to be derived from the interlobular stroma; FIV fibroblasts were tightly associated with the epithelial organoids and are therefore believed to be of intralobular origin. These cells were characterised in terms of their migratory phenotype (classified as either foetal‐ or adult‐like) and the production of motility factors according to previously described techniques. FI fibroblasts obtained from patients with benign breast lesions displayed a foetal migratory phenotype (10/11) and secreted detectable quantities of motility factors (11/11). In contrast, none of the FIV fibroblasts (0/10) obtained from these same patients displayed a foetal‐like migratory phenotype or secreted motility factors. In the case of fibroblasts obtained from cancer patients, both FI (13/13) and FIV (13/13) fibroblasts displayed a foetal‐like migratory phenotype and secreted motility factors. Fibroblasts were also derived from skin (n = 12) and breast fat tissue (n = 4) of certain patients. In agreement with our previously published observations, skin fibroblasts obtained from non‐cancer and cancer patients also differed in terms of their migratory behaviour: none of the skin fibroblast lines (0/5) obtained from non‐cancer patients were foetal‐like, compared to 3/7 lines from cancer patients. All fat‐derived fibroblasts (I non‐cancer and 3 cancer patients) were also foetal‐like. Our results indicate (i) functional heterogeneity between FI and FIV fibroblasts of normal breast, and (ii) the presence of functionally aberrant (i.e., foetal‐like) FIV fibroblasts in histologically normal breast tissue adjacent to a carcinoma.
Evaluation of epstein‐barr virus antibody patterns and detection of viral markers in the biopsies of patients with Hodgkin's disease
Authors: Levine Paul H. , Pallesen Gorm , Ebbesen Peter , Harris Nancy , Evans Alfred S. , Müeller Nancy
Published: February 2007

We assessed the relationship of Epstein‐Barr virus (EBV) serology to the presence or absence of EBV genome in 39 cases of Hodgkin's disease (HD). Biopsies from patients included in 2 previous published studies, I involving patients from the United States (eastern Massachusetts) and I from Denmark, were evaluated for EBV RNA (EBER‐1) and latent membrane protein (LMP‐I). The presence of EBV in Reed‐Sternberg cells in the biopsies correlated with the histologic subtype of HD (mixed cellularity and lymphocyte depletion) but not with IgG antibody titers against the viral capsid antigen (VCA). These data suggest that, unlike Burkitt's lymphoma, the IgG antibody against VCA is not predictive of the presence or absence of EBV in Reed‐Sternberg cells in HD. The predictive value of other antibodies should be evaluated.
Expression of the WT1 Wilms' tumor gene by normal and malignant human melanocytes
Authors: Rodeck Ulrich , Bossler Anna , Kari Csaba , Humphreys Christopher W. , Györfi Tibor , Maurer Jürgen , Thiel Eckhard , Menssen Hans D.
Published: February 2007

We report expression of the wt I (Wilms' tumor) gene by cultured human melanoma cells. Using RNA polymerase chain reaction analysis, wt I transcripts were detected in 7 of 9 melanoma cell lines but not in 5 normal melanocyte strains. In Northern blot analysis, steady‐state wt I mRNA levels were found in 2 of 4 melanoma lines but not in normal melanocytes. Sequence analysis of the wt I cDNA expressed by melanoma cell line WM 902‐B revealed the presence of 4 previously published splice variants but no evidence for mutations in the coding region. Previous work has shown that WT I modulates transcription after binding to the early growth response (EGR)‐I sites present in the platelet‐derived growth factor (PDGF)‐A chain promoter; the PDGF‐A chain gene is known to be expressed by various melanoma cell lines. Based on these findings, we studied the relationship of wt I and PDGF‐A chain gene expression in melanoma cell lines. Co‐expression of the wt I and the PDGF‐A chain genes was observed in 2 melanoma cell lines with mutated p53 but not in 2 melanoma cell lines with wild‐type p53; this result is consistent with a previous report showing that, in the context of absent or mutated p53, WTI acts as a transcriptional activator, whereas in the presence of wild‐type p53 it acts as a repressor.
Distribution of VRA09, an ovarian tumor‐associated antigen, distinguishing borderline serous tumors
Authors: Voeltzel Thibault , Duvillard Pierre , Ghillani Pascale , Bénard Jean , Bohuon Claude , Bellet Dominique , Bidart Jean‐Michel
Published: February 2007

We recently reported the characterization of an antigen designated VRA09, identified by a monoclonal antibody and overexpressed on the surface of vincristine‐resistant human ovarian carcinoma cells. In the present study, we analyze the distribution of this antigen in normal and tumor tissues. Its pattern of expression appears to differ from that described for other drug‐resistance‐ and/or tumor‐associated antigens. In normal tissues, the antigen has a restricted histological distribution and appears to be localized in mesoderm‐derived tissues. In tumor tissues, VRA09 expression was mainly detected in serous ovarian tumors. Indeed, VRA09 is strongly expressed in papillary serous cystadenocarcinomas and their metastases, and more specifically in the basement membranes of serous tumors of borderline malignancy. In contrast, no immunostaining was observed in normal ovarian tissue or benign tumors. The detection of this antigen may help to identify serous ovarian tumors by distinguishing tumors of low malignancy from cystadenocarcinomas.
Elevated levels of benzene‐related compounds in the urine of cigarette smokers
Authors: Ong C. N. , Lee B. L. , Shi C. Y. , Ong H. Y. , Lee H. P.
Published: February 2007

Benzene exposure causes leukemia and lymphomas. Recent epidemiological findings have also shown an association between cigarette smoking and an increased risk of leukemia. However, further evidence is required to document the biological plausibility of this association. In evaluating this link, it is important to note that cigarette smoke contains benzene and various pyrolytic compounds, among other carcinogens. This study aims to determine the uptake of benzene by measuring 3 benzene‐related compounds in cigarette smokers and non‐smokers. Urinary concentrations of catechol (CAT), hydroquinone (HQ), and trans,trans‐muconic acid (tt‐MA) were measured by high‐performance liquid chromatography (HPLC) with fluorimetric and UV detection, respectively. The results showed that these compounds were present in all urine samples. However, the concentrations were significantly higher in smokers than in non‐smokers. The mean level of urinary tt‐MA was 0.19 ± 0.09 mg/g creatinine for 46 male smokers and the corresponding value for 40 non‐smokers was 0.14 ± 0.07 mg/g creatinine. The mean concentrations of HQ and CAT were 0.81 ± 0.4 and 3.51 ± 2.6 mg/g creatinine for smokers, and 0.45 ± 0.4 and 1.94 ± 1.2 mg/g creatinine for non‐smokers, respectively. These results suggest that cigarette smoking is associated with a significant additional exposure to benzene and its related compounds. Furthermore, significant correlations were observed between the concentrations of cotinine, the metabolite of nicotine, and the above compounds. These findings suggest that the exposure originated from cigarette smoking.
Tomatoes and risk of digestive‐tract cancers
Authors: Franceschi Silvia , Bidoli Ettore , Vecchia Carlo La , Talamini Renato , D'Avanzo Barbara , Negri Eva
Published: February 2007

In view of the persisting uncertainty concerning possible mechanisms by which high vegetable and fruit intake decreases cancer risk, foods with divergent values for potentially important micronutrients are a priority for investigation. Tomatoes are low in beta‐carotene, but high in lycopene, an active antioxidative agent. In order to assess the effect of tomatoes on risk of cancers of the digestive tract, data were analyzed from an integrated series of case‐control studies conducted between 1985 and 1991 in northern Italy, where tomato intake is high but, also, heterogeneous. The overall dataset included the following histologically confirmed cancer cases: oral cavity and pharynx, 314; esophagus, 85; stomach, 723; colon, 955; and rectum, 629; and a total of 2,879 controls admitted to hospital for acute non‐neoplastic or non‐digestive conditions, unrelated to long‐term dietary modifications. Multivariate odds ratios (OR) and 95% confidence interval (CI) for subsequent quartiles of intake of raw tomatoes were derived, after allowance for age, sex, study center, education, smoking and drinking level, and tertile of total caloric intake. There was a consistent pattern of protection for all sites (OR in the upper quartile ranging between 0.4 and 0.7), most notably for gastrointestinal neoplasms. All trends in risk were highly significant. The beneficial effect of raw tomatoes in this population may be partly due to the fact that they constitute perhaps the most specific feature of the Mediterranean diet. However, if it is true that tomatoes protect against digestive‐tract cancers, this is of interest from both a scientific and a public health viewpoint.
Loss of polarity and De novo expression of the β1 family of integrins in thyroid tumors
Authors: Vitale Mario , Bassi Vincenzo , Illario Maddalena , Fenzi Gianfranco , Casamassima Adele , Rossi Guido
Published: February 2007

The expression and cell‐membrane distribution of the β1 family of integrins (very‐late‐activation antigens, VLA) were investigated in benign and malignant human thyroid tumors. We compared tissue samples of normal glands, nodular goiters, adenomas and carcinomas. We also examined 3 thyroidcarcinoma cell lines cultured in vitro. The expression of subunits of the β1 family of integrins was assessed by flow cytometry and specific antibodies in dispersed single‐cell suspensions and by immunofluorescence on frozen tissue sections. In contrast to the heterogeneity of the expression of β1 integrins observed in other tumors, thyroid neoplastic lesions showed a remarkably constant VLA profile. In all tumors, benign as well as malignant, and in carcinoma cell lines, all sub‐units of β1 integrins were expressed at high levels. While sub‐units α1, α3, α5, α6 and occasionally α2 were also present in a cell sub‐set of normal glands and nodular goiters, expression of α4 was restricted to neoplastic lesions; this integrin can be therefore considered an antigen associated with thyroid tumors. It has been reported that in normal glands and in nodular goiters, the expression of β1 integrins is restricted to the basal‐cell membrane. Immunofluorescence on tissue sections showed instead that, in adenomas and carcinomas, the polarized distribution of these integrins on the cell membrane is lost.
Generation of an antitumour immune response to a murine mesothelioma cell line by the transfection of allogeneic mhc genes
Authors: Leong Clement C. , Robinson Bruce W. S. , Garlepp Michael J.
Published: February 2007

We have determined whether transfection and expression of allogeneic MHC genes in a murine mesothelioma cell line can generate an anti‐tumour immune response. The MHC genes encoding H‐2Kb and H‐2Dd were transfected into the mesothelioma cell line AC29 (derived from CBA mice, H‐2k) and transfectant clones isolated. Each of five H‐2Kb and 4 H‐2Dd transfectant clones were unable to form tumours in CBA mice, although they had maintained their ability to form tumours in F1 crosses of CBA ± C57b1/10 or CBA ± BALB/c, respectively. Thus the tumours expressing the transfected MHC genes were rejected only in an allogeneic setting. Mice without tumours after transfectant challenge were inoculated on the opposite flank with 1 ± 106 parental AC29. There was no evidence of systemic immunity to the parental cell line since tumours formed at the same rate as in naive mice. The mixing of allogeneic MHC transfectants with parental AC29 did, however, retard the growth of parental tumour. Our study illustrates that the expression of allogeneic MHC molecules on a highly immunosuppressive and non‐immunogenic murine malignant mesothelioma cell line was able to stimulate rejection of tumour cells but was incapable of generating a systemic protective response against the parental cell line.
DNA of lymphoma‐associated herpesvirus (HVMF1) in SIV‐infected monkeys (Macaca fascicularis) shows homologies to EBNA‐1, ‐2 and ‐5 genes
Authors: Li Su Ling , Biberfeld P. , Ernberg I.
Published: February 2007

We have characterized a new Epstein‐Barr‐virus(EBV)‐like herpesvirus associated with lymphomas of SIV‐infected cynomolgus (Macaca fascicularis) monkeys and propose that this virus is designated herpesvirus macaca fascicularis I (HVMFI). Genomic regions in HVMFI of potential significance for tumor pathogenesis were analyzed by Southern blotting, PCR and sequencing, and compared with human EBV DNA. Virus from 7 SIV‐associated lymphomas and one lymphoma‐derived cell line were shown to share homology with the EBNAI‐ and EBNA2‐coding regions of EBV, while some homology to EBV‐LMPI was detectable only at low‐stringency hybridization. Homologous regions to the long internal repeat (IRI; BamHI W), the EBERI and 2 and the latent origin of DNA replication (oriP) could also be demonstrated in HVMFI. These coding regions, except IRI, showed restriction‐enzyme maps different from those of EBV. Sequencing of the EBNA5 homologous region of HVMFI DNA, corresponding to exons W1 and W2, showed 65% homology to the EBV exons W1 and W2, and 80% to the whole region including the intron. Since EBNA5 has been reported to bind tumor‐suppressor proteins p53 and Rb in vitro, the HVMFI homology could be important for the lymphomagenic capacity of this monkey herpesvirus.