A prostate-specific gene, PCGEM1, was identified by differential display analysis of paired normal and prostate cancer tissues. Multiple tissue Northern blot analysis revealed that PCGEM1 was expressed exclusively in human prostate tissue. Analysis of PC-GEM1 expression in matched normal and primary tumor specimens revealed tumor-associated overexpression in 84% of patients with prostate cancer by in situ hybridization assay and in 56% of patients by reverse transcription-PCR assay. Among various prostate cancer cell lines analyzed, PCGEM1 expression was detected only in the androgen receptor-positive cell line LNCaP. Extensive DNA sequence analysis of the PCGEM1 cDNA and genomic DNA revealed that PCGEM1 lacks protein-coding capacity and suggests that it may belong to an emerging class of noncoding RNAs, also called ''riboregulators.'' The PCGEM1 locus was mapped to chromosome 2q32. Taken together, the remarkable prostate-tissue specificity and androgen-dependent expression of PCGEM1 as well as its elevated expression in a significant percentage of tumor tissues suggest specific functions of PCGEM1 in the biology and tumorigenesis of the prostate gland.riboregulator ͉ differential display ͉ androgen regulation ͉ noncoding RNA

A rapid (< 2.5 hrs) method for single-strand conformation polymorphism (SSCP) analysis of PCR products that allows the use of ethidium bromide staining is described. PCR products ranging in size from 117 to 256 bp were evaluated for point mutations and polymorphisms by 'cold SSCP' in commercially available pre-cast polyacrylamide mini-gels. Several electrophoretic parameters (running temperature, buffers, denaturants, DNA concentration, and gel polyacrylamide concentration) were found to influence the degree of strand separation and appeared to be PCR fragment specific. Use of the 'cold' SSCP technique and the mini-gel format allowed us to readily optimize the electrophoretic conditions for each PCR fragment. This greatly increased our ability to detect polymorphisms compared to conventional, radioisotope-labeled 'hot' SSCP, typically run under two standard temperature conditions. Excellent results have been obtained in resolving mutant PCR fragments from human p53 exons 5 through 8, human HLA-DQA, human K-ras exons 1 and 2, and rat K-ras exon 3. Polymorphisms could be detected when mutant DNA comprised as little as 3% of the total gene copies in a PCR mixture. Compared to standard 'hot' SSCP, this novel non-isotopic method has additional advantages of dramatically increased speed, precise temperature control, reproducibility, and easily and inexpensively obtainable reagents and equipment. This new method also lacks the safety and hazardous waste management concerns associated with radioactive methods.

We have used structure-based design techniques to introduce the drug O 2 -[2,4-dinitro-5-(N-methyl-N-4-carboxyphenylamino) phenyl] 1-N,N-dimethylamino)diazen-1-ium-1,2-diolate (PABA/NO), which is efficiently metabolized to potentially cytolytic nitric oxide by the isoform of glutathione S-transferase, an enzyme expressed at high levels in many tumors. We have used mouse embryo fibroblasts (MEFs) null for GST (GST Ϫ/Ϫ ) to show that the absence of GST results in a decreased sensitivity to PABA/NO. Cytotoxicity of PABA/NO was also examined in a mouse skin fibroblast (NIH3T3) cell line that was stably transfected with GST and/or various combinations of ␥-glutamyl cysteine synthetase and the ATP-binding cassette transporter MRP1. Overexpression of MRP1 conferred the most significant degree of resistance, and in vitro transport studies confirmed that a GST-activated metabolite of PABA/NO was effluxed by MRP1 in a GSHdependent manner. Additional studies showed that in the absence of MRP1, PABA/NO activated the extracellular-regulated and stress-activated protein kinases ERK, c-Jun NH 2 -terminal kinase (JNK), and p38. Selective inhibition studies showed that the activation of JNK and p38 were critical to the cytotoxic effects of PABA/NO. Finally, PABA/NO produced antitumor effects in a human ovarian cancer model grown in SCID mice.

LAMP3 (DC-LAMP, TSC403, CD208) was originally isolated as a gene specifically expressed in lung tissues. LAMP3 is located on a chromosome 3q segment that is frequently amplified in some human cancers, including uterine cervical cancer. Because two other members of the LAMP family of lysosomal membrane glycoproteins, LAMP1 and LAMP2, were previously implicated in potentially modulating the interaction of vascular endothelial and cancer cells, we hypothesized that LAMP3 might also play an important part in metastasis. To clarify the metastatic potential of LAMP3 in cervical cancers, we transfected a LAMP3 expression vector into a human uterine cervical cancer cell line, TCS. In an in vitro invasion assay, the migration of LAMP3-overexpressing TCS cells was significantly higher than in control TCS cells. In an in vivo metastasis assay, distant metastasis was detected in 9 of 11 LAMP3-overexpressing TCS cell-injected mice and in only 1 of 11 control mice. Histologic study showed that LAMP3-overexpressing cells readily invaded into the lymph-vascular space. In clinical samples, quantitative real-time reverse transcription-PCR (RT-PCR) analyses showed that LAMP3 mRNA was significantly up-regulated in 47 of 47 (100%) cervical cancers and in 2 of 15 (13%) cervical intraepithelial neoplasias, compared with a low level of LAMP3 mRNA expressed in normal uterine cervixes. Interestingly, high LAMP3 expression was significantly correlated with the overall survival of patients with stage I/II cervical cancers. These findings indicate that LAMP3 overexpression is associated with an enhanced metastatic potential and may be a prognostic factor for cervical cancer. (Cancer Res 2005; 65(19): 8640-5)

PABA/NO is a diazeniumdiolate of structure Me(2)NN(O)=NOAr (where Ar is a 5-substituted-2,4-dinitrophenyl ring whose 5-substituent is N-methyl-p-aminobenzoic acid). It has shown activity against human ovarian cancer xenografts in mice rivaling that of cisplatin, but it is poorly soluble and relatively unstable in water. Here we report structure-based optimization efforts resulting in three analogues with improved solubility and stability in aqueous solution. We sought to explain PABA/NO's physicochemical uniqueness among these four compounds, whose aminobenzoic acid precursors differ structurally only in the presence or absence of the N-methyl group and/or the position of the carboxyl moiety (meta or para). Studies revealed that PABA/NO's N-methyl-p-aminobenzoic acid substituent is bound to the dinitrobenzene ring via its carboxyl oxygen while the other three are linked through the aniline nitrogen. This constitutes a revision of the previously published PABA/NO structure. All four analogues reacted with GSH to produce bioactive nitric oxide (NO), but PABA/NO was the most reactive. Consistent with PABA/NO's potent suppression of A2780 human ovarian cancer xenograft growth in mice, it was the most potent of the four in the OVCAR-3 cell line.

A large variety of human tumours manifest a heterozygous or homozygous deletion in the 9p21 chromosome region. The list includes malignant melanoma, glioma, lung, bladder, pancreatic and renal cancers (Kamb et al, 1994;Nobori et al, 1994), as well as gynaecological tumours (reviewed by Wong et al, 1997). Two putative tumour suppressor genes have been identified in this region: p16 (also known as p16 INK4A , cyclin-dependent kinase 4 inhibitor, CDK4I, CDKN2, and MTS1), and p15 (p15 INK4B ).The p16 gene makes two different proteins, p16 and p19 ARF (p19 alternative reading frame), using different overlapping reading frames, starting with different first exons. The p16 protein uses exon 1α, and p19 ARF uses exon 1β; these two exons are alternatively spliced to the same second and third exons. The p16 and p15 proteins belong to a family of negative regulators of the cell cycle. Specific binding of p16 protein to the CDK4 or CDK6 cyclindependent protein kinases inhibits the phosphorylation activity of CDK-cyclin D complexes towards the nuclear RB/E2F protein complex (Serrano et al, 1993). p16 normally prevents phosphorylation of RB, resulting in RB's retention of E2F. Failure to release E2F at the late G1 checkpoint blocks the cell from entering the S phase (Hengstschläger et al, 1996;Lukas et al, 1996). The p19 ARF protein, although it has an unrelated amino acid sequence, has cell cycle arresting functions. It is the p16 protein that now appears to be the major target of mutations and deletions at the 9p21 loci.The p15 (MTS2) putative tumour suppressor gene is located 25 kb centromeric of the p16 gene on 9p. p15 contains sequences highly homologous to exon 2 of p16 and, like p16, inhibits both CDK4 and CDK6 kinase activities (Guan et al, 1994;Hannon and Beach, 1994). Homozygous deletions of p15 and hypermethylation-associated loss of p15 expression have been reported in glioblastomas (Jen et al, 1994).The p16/p19 ARF and p15 genes appear to play variably important roles in human tumorigenesis, with critical tissue specificities and uncertain implications for clinical prognoses. Little is currently known about the potential role of these genes in reproductive tract biology, and specifically in uterine tumours. We have begun to examine the expression of the p16 gene at the level of mRNA and protein, the methylation status of the 5′-CpG island of p16 exon 1α, and for p16 point mutations and homozygous deletions in these tumours. We have also analysed the p15 gene for mutations and homozygous deletions. We report that the inactivation of the p16 gene, either by homozygous gene deletion, mutation or loss of protein expression, occurs in a small but significant subset of these uterine tumours. Summary The roles of the p16 and p15 inhibitor of cyclin-dependent kinase tumour suppressor genes were examined in human uterine cervical and endometrial cancers. p16 mRNA, examined by reverse transcription polymerase chain reaction (RT-PCR), was significantly reduced in five of 19 (26%) cervical and four of 25 (16%) endometrial tu...

The role of the replication error-positive (RER+) phenotype in the development of specific subtypes of sporadic ovarian carcinomas was examined by screening for the presence of microsatellite instability (MI) in 47 tumors. The overall frequency of ovarian MI was 17% only. However, MI occurred in 50% of the ovarian endometrioid-type tumors, which was significantly more often than in all the other histological subtypes combined (8%). Five of the 8 RER+ tumors exhibited most marked type I instability, possibly representing a different mechanism than for the remaining type 2 tumors. The cDNA of the mutation suppression gene hMSH2, the gene most often associated with MI, was screened for alterations in 8 MI-positive and 5 MI-negative ovarian tumors. Only 3 changes were found. Complete loss of hMSH2 mRNA expression was detected in I tumor, while another expressed only an abnormal transcript containing a deletion of exon 3. One additional RER+ serous adenocarcinoma contained a rare polymorphism with a non-conservative amino acid change. One of 8 RER+ tumors showed loss of heterozygosity at the hMSH2 loci. Genetic instability, caused in part by alterations in the hMSH2 gene, may play an important role in the sporadic endometrioid subtype of ovarian tumors. Other mutator-phenotype genes may be responsible for the remaining cases of RER+ ovarian tumors.

Our study revealed a clear progression of increased p53 alteration from untreated primary to hormone refractory disease (p < 0.00005).