[Research advances on the mechanism of Wnt/ß-catenin signaling pathway in body surface wound healing].

Wound healing is a slow and complex biological process, including inflammatory reaction, cell proliferation, cell differentiation, cell migration, angiogenesis, extracellular matrix deposition, tissue remodeling, and so on. Wnt signaling pathway can be divided into classical pathway and non-classical pathway. Wnt classical pathway, also known as Wnt/ß-catenin signaling pathway, plays an important role in cell differentiation, cell migration, and maintenance of tissue homeostasis. Many inflammatory factors and growth factors are involved in the upstream regulation of this pathway. The activation of Wnt/ß-catenin signaling pathway plays an important role in the occurrence, development, regeneration, repair and related treatment of skin wounds. This article review the relationship between Wnt/ß-catenin signaling pathway and wound healing, meanwhile summarizes its effects on important processes of wound healing, such as inflammation, cell proliferation, angiogenesis, hair follicle regeneration, and skin fibrosis, as well as the role of inhibitors of Wnt signaling pathway in wound healing.

[Risk stratification of type-specific human papillomavirus for cervical precancers: evidence from a cross-sectional study in Shenzhen].

Objective: To analyze the epidemiological genotype features of human papillomavirus (HPV) in cervical infection and their risks for cervical precancers among women in Shenzhen area. Methods: A total of 2 717 individuals ranging in age from 30~59 years were recruited in 18 community health centers of Shenzhen city from March 1 to June 15, 2015 by a cluster sampling method. The results of genotype of HPV, liquid-based cytology (LBC), colposcopy and pathology were analyzed. The clinical sensitivity and specificity as well as positive (PPV) and negative (NPV) predictive values of the combination of different HPV genotype in screening the cervical intraepithelial neoplasia (CIN) 2 and above were estimated. Results: The HPV infection rate in Shenzhen area was 15.9% (432/2 717). The most common HPV genotype was HPV52 (22.9%), followed by HPV16 (12.7%), HPV53 (10.0%), HPV51 (8.6%) and HPV58 (8.1%). Compared with HPV16/18 genotyping, HPV33/16 genotyping had a higher sensitivity (57.1% vs. 42.9%, P<0.05) and an analogous specificity (87.3% vs. 86.9%, P>0.05) in predicting CIN2+ . The sensitivity of combination of HPV33/16 genotyping and low grade squamous intraepithelial lesion (LSIL) positive tested by LBC in predicting CIN2+ was 75.0%, significantly higher than 64.3% of atypical squamous cells of undetermined significance (ASC-US) positive tested by LBC alone (P<0.05). The specificities of these two methods mentioned above in predicting CIN2+ were 83.5% and 89.2%, respectively, without statistical difference (P>0.05). Conclusions: Women infected by HPV have distinct risks for CIN2+ according to different high-risk HPV genotypes. The top five risks were HPV 33, 16, 58, 56, and 68. HPV-positive women triaged by LBC LSIL+ combined with HPV33/16 genotyping may be a potential strategy for cervical cancer screening in developed urban area.

[Distribution and associated factors of high-risk HPV genotypes infection among HPV-positive women who participated cervical screening test in Shenzhen, 2014-2016, China].

Objective: To analyze the distribution and associated factors of high-risk genotypes of HPV in cervical infection among women in Shenzhen. Methods: The information on sociodemographic characteristics and HPV genotypes of HPV-positive women who participated cervical screening test from January 2014 to December 2016 was downloaded from Shenzhen Maternity and Child Healthcare Management Information System. According to the pathogenicity, the high-risk HPV genotypes were divided into 15 types including HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68; and there were 6 low-risk genotypes including HPV 6, 11, 42, 43, 44, and 81. Chi-square tests were applied to compare the proportions of high-risk HPV infection among women who had different sociodemographic characteristics. A non-conditional logistic regression model was used to analyze the associated factors for high-risk HPV infection. Results: In total, all HIV positives received HPV genotyping, with an average age of (38.08±9.38) years old. There were 9 979 (93.9%) high-risk and 645 (6.1%) low-risk HPV infections. The proportions of HPV infections for high-risk type in each year were 91.5%, 93.8%, and 95.6%, increasing with the screening years (χ(2)=54.79, P<0.001). Multivariate logistic regression analysis showed that compared with women younger than 25 years old, women in other age groups (at age 26 to 30 years, 31 to 35 years, 36 to 40 years, 41 to 45 years, and 50 years or older) had increased risks of high-risk HPV infection, with OR (95%CI) of 1.67 (1.20-2.31), 1.49 (1.09-2.03), 1.71 (1.23-2.37), 1.65 (1.19-2.31), and 1.84 (1.26-2.67), respectively; compared with the married, single women had a decreased risk of high-risk HPV infection (OR (95%CI): 0.71 (0.50-1.00)); women received HPV testing in 2015 and 2016 showed higher risk of high-risk HPV infection than those in 2014 (OR (95%CI): 1.43 (1.17-1.74) and 2.03 (1.68-2.46)). The 5 most common HPV genotypes were HPV52 (25.1%, 2 670 cases), followed by HPV16 (19.2%, 2 041 cases), HPV58 (13.3%, 1 413 cases), HPV18 (9.9%, 1 048 cases), and HPV51 (9.3%, 993 cases). Conclusion: Age, marital status, and screening year were associated with high-risk HPV infections. Besides HPV16 and HPV18, the prevention and control on HPV infections for HPV52, HPV58, and HPV51 should be prioritized in Shenzhen area.

Effects of Δ(9)-tetrahydrocannabinol (THC) on human amniotic epithelial cell proliferation and migration.

BACKGROUND: The deleterious effects of cannabis consumption for fertility and pregnancy outcome are recognized for years. The main psychoactive molecule of cannabis, Δ(9)-tetrahydrocannabinol (THC) is able to cross the placenta barrier and cause alterations in fetal growth, low birth weight and preterm labor. However, the effects of THC on the human placenta amnion are still unknown. METHODS: The distributions of CB1R and CB2R in human amnion tissues were observed by immunohistochemistry (IHC). Human amniotic epithelial cell proliferation and migration in response to THC treatment were measured by MTS and transwell assays, respectively. The PCR array was performed to study the key regulators involved in the cell migration. The protein levels of CB1R, CB2R in amnion tissues and MMP2, MMP9 in cells were detected by western blotting. Small interfering RNAs (siRNAs) were used to knockdown MMP2 and MMP9 in WISH cells. RESULTS: Our results indicated that both CB1R and CB2R primarily identified in the epithelial layer of human placental amnion tissue. The CB1R expression in the amnion tissue was higher in the preterm group than normal control. High-dose of THC (30uM, but not 20 and 10uM) significantly inhibited (p<0.01) human amniotic epithelial cell lines (WISH) proliferation. Meanwhile, THC at both 10uM and 20uM (p<0.05) significantly suppressed cells migration in both WISH and primary human amniotic epithelial cells. The PCR array data and siRNA experiments demonstrated that MMP2/9 were tightly involved in the regulation of THC-inhibited cell migration in WISH cells. CONCLUSION: These results suggested that THC inhibited the migration of human amniotic epithelial cell through the regulation of MMP2 and MMP9, which in turn altered the development of the amnion during the gestation and partially resulted in preterm labor and other adverse pregnancy outcomes.

Improved production of transgenic Dioscorea zingiberensis (Dioscoreaceae) by Agrobacterium tumefaciens-mediated transformation.

The establishment of high-efficiency Agrobacterium-mediated transformation techniques could improve the production of Dioscorea zingiberensis, a medicinal species with a high diosgenin content. We co-cultivated embryogenic calli induced from mature seeds with A. tumefaciens strain EHA105. A binary vector, pCAMBIA1381, which contains the gfp and hpt genes under the control of the ubiquitin promoter and the CaMV 35S promoter, respectively, was used for transformation. Pre-culture, basic medium, acetosyringone, and bacterial density were evaluated to establish the most efficient protocol. The optimal conditions consisted of MS medium without CaCl(2) for pre- and co-cultivation, three days for pre-culture, addition of 200 µM AS, and an OD(600) of 0.5. The transgenic plants grown under selection were confirmed by PCR analysis and Southern blot analysis. This protocol produced transgenic D. zingiberensis plants in seven months, with a transformation efficiency of 6%.

Sexual reproduction development in apomictic Eulaliopsis binata (Poaceae).

Apomixis is a particular mode of reproduction that allows progeny formation without meiosis and fertilization. Eulaliopsis binata, a tetraploid apomictic species, is widely used for making paper, rope and mats. There is great potential for fixation of heterosis in E. binata due to autonomous endosperm formation in this species. Although most of its embryo sac originates from nucellus cells, termed apospory, we observed sexual reproduction initiation in 86.8 to 96.8% of the ovules, evidenced by callose deposition on the walls of cells undergoing megasporogenesis. However, only 2-3% mature polygonum-type sexual embryo sacs were confirmed by embryological investigation. Callose was not detected on aposporous initial cell walls. The aposporous initial cells differentiated during pre- and post-meiosis of the megaspore mother cell, while the sexual embryo sac degenerated at the megaspore stage. DNA content ratio of embryo and endosperm in some individuals was 2C:3C, based on flow cytometry screening of seed, similar to that of normal sexual seed. These results confirm that apomictic E. binata has conserved sexual reproduction to a certain degree, which may contribute to maintaining genetic diversity. The finding of sexual reproduction in apomictic E. binata could be useful for research on genetic mechanism of apomixis in E. binata.

Mitochondrial DNA depletion in prostate epithelial cells promotes anoikis resistance and invasion through activation of PI3K/Akt2.

Neoplastic transformation of prostate epithelium involves aberrant activation of anti-apoptotic and pro-invasive pathways triggered by multiple poorly understood genetic events. We demonstrated earlier that depletion of mitochondrial DNA (mtDNA) induces prostate cancer progression. Here, using normal prostate epithelial PNT1A cells we demonstrate that mtDNA depletion prevents detachment-induced apoptosis (anoikis) and promotes migratory capabilities onto basement membrane proteins through upregulation of p85 and p110 phosphatidylinositol 3-kinase (PI3K) subunits, which results in Akt2 activation and phosphorylation of downstream substrates GSK3beta, c-Myc, MMP-9, Mdm2, and p53. Pharmacological or genetic PI3K inhibition, siRNA-mediated Akt2 depletion, as well as mtDNA reconstitution were sufficient to restore sensitivity to anoikis and curtail cell migration. Moreover, Akt2 activation induced glucose transporter 1 (GLUT1) expression, glucose uptake, and lactate production, common phenotypic changes seen in neoplastic cells. In keeping with these findings, several prostate carcinoma cell lines displayed reduced mtDNA content and increased PI3K/Akt2 levels when compared to normal PNT1A cells, and Akt2 downregulation prevented their survival, migration and glycolytic metabolism. On a tissue microarray, we also found a statistically significant decrease in mtDNA-encoded cytochrome oxidase I in prostate carcinomas. Taken together, these results provide novel mechanistic evidence supporting the notion that mtDNA mutations may confer survival and migratory advantage to prostate cancer cells through Akt2 signaling.

Hepatic 'stem cell' malignancies in adults: four cases.

AIMS: Combined hepatocellular/cholangiocarcinomas have been explained by some investigators as bidirectional differentiation of neoplastic progenitor cell populations. The presence of hepatic progenitor cells has now been confirmed in humans, though whether they can give rise to malignant tumours has not been confirmed. We report four cases of small tumours identified in livers with features of chronic hepatitis which may suggest a role for malignant transformation of hepatic stem cells in hepatic malignancies. METHODS: Tumour samples were studied from four patients by histochemistry and immunohistochemistry. RESULTS: Two patients had chronic hepatitis B, one had chronic hepatitis C and chronic alcoholic liver injury, and one had non-B non-C chronic hepatitis. Stages of disease ranged from portal fibrosis to cirrhosis. All tumours contained undifferentiated cells with morphological and immunohistochemical features that would be expected of hepatic progenitor cells. These cells merged with both hepatocellular carcinoma and cholangiocarcinoma components as well as with mature appearing hepatocytes within the tumours. CONCLUSION: We suggest that these tumours are of hepatic progenitor cell origin, supporting the concepts that human hepatocarcinogenesis can be based on transformation of progenitor cells and that such a process may underlie development of some mixed hepatocellular/cholangiocarcinomas and dysplastic nodules.

Fine-needle aspiration biopsy of peripheral T-cell lymphomas. A cytologic and immunophenotypic study of 33 cases.

INTRODUCTION: Peripheral T-cell lymphoma (PTCL) accounts for 10-20% of all non-Hodgkin lymphomas in the United States. In this study, the authors reviewed the cytologic and immunophenotypic findings of 33 fine-needle aspirations (FNAs) of PTCL. METHODS: Thirty-three FNAs from 26 patients (12 females and 14 males) with PTCL were identified during 1991-1999. The patients' age ranged from 19 to 96 years. Immunophenotyping was performed in 24 cases by using either flow cytometry (FC; 21 cases) or immunocytochemistry (IC; 3 cases). Follow-up included review of prior or current histology and clinical records. RESULTS: Nine cases were associated with mycosis fungoides, three cases were classified as T-cell chronic lymphocytic leukemia, and two were angioimmunoblastic adenopathy (AILD)-like T-cell lymphoma. The remaining 19 were classified as PTCL, not otherwise specified. The latter consisted of eight mixed cell variant, eight large cell variant, and three anaplastic variant. One of the mixed cell variant and one of the large cell variants contained numerous epithelioid histiocytes (Lennert lymphoma). Thirty (91%) cases had a definitive diagnosis of malignant lymphoma. Twenty-two cases (2 IC and 20 FC) showed a predominant population of T lymphocytes without a monoclonal B-cell population. In addition, FC revealed an aberrant expression of T-cell markers in 13 cases. Two cases were interpreted as "atypical lymphoid population"; one case was an AILD-like T-cell lymphoma, and the other case was PTCL, large cell type. One case initially was interpreted as granulomatous lymphadenitis; subsequent biopsy revealed PTCL, Lennert type. CONCLUSIONS: Peripheral T-cell lymphoma is a heterogeneous group of lesions with diverse cytomorphology. Cytologic analysis and immunophenotyping is an accurate method of diagnosing peripheral T-cell lymphoma.

Functional conservation of phosphorylation-specific prolyl isomerases in plants.

The phosphorylation-specific peptidyl prolyl cis/trans isomerase (PPIase) Pin1 in humans and its homologues in yeast and animal species play an important role in cell cycle regulation. These PPIases consist of an NH(2)-terminal WW domain that binds to specific phosphoserine- or phosphothreonine-proline motifs present in a subset of phosphoproteins and a COOH-terminal PPIase domain that specifically isomerizes the phosphorylated serine/threonine-proline peptide bonds. Here, we describe the isolation of MdPin1, a Pin1 homologue from the plant species apple (Malus domestica) and show that it has the same phosphorylation-specific substrate specificity and can be inhibited by juglone in vitro, as is the case for Pin1. A search in the plant expressed sequence tag data bases reveals that the Pin1-type PPIases are present in various plants, and there are multiple genes in one organism, such as soybean (Glycine max) and tomato (Lycopersicon esculentum). Furthermore, all these plant Pin1-type PPIases, including AtPin1 in Arabidopsis thaliana, do not have a WW domain, but all contain a four-amino acid insertion next to the phospho-specific recognition site of the active site. Interestingly, like Pin1, both MdPin1 and AtPin1 are able to rescue the lethal mitotic phenotype of a temperature-sensitive mutation in the Pin1 homologue ESS1/PTF1 gene in Saccharomyces cerevisiae. However, deleting the extra four amino acid residues abolished the ability of AtPin1 to rescue the yeast mutation under non-overexpression conditions, indicating that these extra amino acids may be important for mediating the substrate interaction of plant enzymes. Finally, expression of MdPin1 is tightly associated with cell division both during apple fruit development in vivo and during cell cultures in vitro. These results have demonstrated that phosphorylation-specific PPIases are highly conserved functionally in yeast, animal, and plant species. Furthermore, the experiments suggest that although plant Pin1-type enzymes do not have a WW domain, they may fulfill the same functions as Pin1 and its homologues do in other organisms.

Isolation of three distinct CycD3 genes expressed during fruit development in tomato.

Tomato (Lycopersicon esculentum Mill.) is an important fruit crop world-wide and a model for studying fruit development. As determined using flow cytometry, fruit growth was characterized by high cell division activity in tomato during the first week after anthesis and followed by endoreduplications (DNA replication without cell divisions). D-type cyclins are considered to be important parts of the signal transduction for stimulation of DNA replication and cell division. To study the function of D cyclins in fruit development, full-length cDNA clones for three D cyclin genes were isolated from young tomato fruit. They were classified as D3 cyclins by sequence similarities and a phylogenetic analysis and named as LeCycD3;1, LeCycD3;2 and LeCycD3;3. The deduced amino acid sequences for LeCycD3;1-3 contained a retinoblastoma-binding motif and a PEST-destruction motif. Pollination and fertilization were followed by a high increase in the transcript levels of LeCycD3;1-3 in young fruit. Using in situ hybridization, high expression of LeCycD3;3 was detected in the vascular tissue of young fruit suggesting a role in vascular development. The D3 cyclins are probably involved in transducing the signals leading to fruit growth by cell divisions. Distinct differences were detected in their temporal and spatial expression patterns suggesting that they play different roles in fruit development as well as in the development of other plant organs.

Adenomyoma arising in a meckel diverticulum: case report and review of the literature.

We report a case of adenomyoma of the small intestine arising in a Meckel diverticulum. The patient was a 22-month-old boy who presented with signs and symptoms of intussusception. At surgery, a Meckel diverticulum was found and removed. On histologic examination, a tumor consisting of dilated cystic glands and smooth muscle bundles was identified. A diagnosis of adenomyoma arising in a Meckel diverticulum was made. A review of the literature showed that only six other pediatric cases of adenomyoma of the small intestine have been reported. The presence of an adenomyoma in a young patient within a Meckel diverticulum favors the view that adenomyomas are a variant of pancreatic heterotopia.

MDH1: an apple homeobox gene belonging to the BEL1 family.

Differential display was used to isolate genes differentially expressed early in fruit development of apple (Malus domestica Borkh.). This approach resulted in the isolation of MDH1, a homeobox gene with a homeodomain similar to that of BELL1 (BEL1), which is involved in regulation of ovule development in Arabidopsis. However, outside the homeodomain MDH1 is quite different from BEL1. In apple, MDH1 mRNA was predominantly found in flowers, expanding leaves and expanding fruit. In pre-anthesis flowers, in situ hybridization showed that MDH1 mRNA accumulated in ovules. To further investigate the function of this new homeobox gene, MDH1 was transformed into Arabidopsis thaliana under the control of the cauliflower mosaic virus 35S promoter. The transgenic Arabidopsis plants showed dwarfing, reduced fertility and changes in carpel and fruit (silique) shape. The size and shape of the cells in the transgenic fruit was irregular. Both the transgenic phenotypes in Arabidopsis and the expression pattern of this gene in apple are consistent with the idea that MDH1 is likely to play an important role in control of plant fertility.

Lipid-rich follicular carcinoma of the thyroid in a patient with McCune-Albright syndrome.

A 41-year-old woman with McCune-Albright syndrome and a 2-cm thyroid nodule of ten years' duration presented for fine-needle aspiration, which yielded vacuolated clear cells with granular chromatin in pseudopapillary arrangement. The resected tumor showed 90% clear cells and 10% nonclear cells with capsular and vascular invasion. The cytoplasmic vacuoles in the clear cells were 3+ for oil red O stain in touch imprint cytology. Immunohistochemistry demonstrated thyroglobulin positivity in the nonclear neoplastic cells, whereas most of the clear cells were negative. Ultrastructural study demonstrated the gradual transition from protein synthesis to lipid synthesis as the neoplastic cells progressed from nonclear to clear. The study suggested that the lipid accumulation resulted from the uncontrolled fatty acid synthesis in the neoplastic cells rather than metaplasia. The karyotype of the tumor cells was normal, 46XX. Literature of lipid-rich thyroid neoplasms were reviewed.

Demonstration of communication between alveolus and interstitium in persistent interstitial pulmonary emphysema: case report.

Persistent interstitial pulmonary emphysema (PIPE) is an uncommon complication of premature infants suffering from hyaline membrane disease who have been treated with mechanical ventilation. The presumed mechanism for the development of the disease is via a break in the bronchioalveolar system that allows air to escape into the interstitium. We report a case of a 9-week-old child who developed the localized form of the disease and underwent a lobectomy. Immunohistochemical stains helped to demonstrate the communication between the airway system and interstitium. This report strengthens the theory that the disease develops from airway rupture at the alveolar level.

Ethylene inhibitors enhance in vitro root formation from apple shoot cultures.

Effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and three ethylene inhibitors, AgNO3, aminoethoxyvinyglycine (AVG) and CoCl2, on root formation were tested in vitro using shoot cultures of the apple (Malus×domestica Borkh.) cultivar Royal Gala. ACC inhibited root formation by delaying root emergence and increasing callus formation at the bases of shoots. In contrast, ethylene inhibitors promoted root formation. Both AgNO3 and AVG at the appropriate concentrations increased the percentage of shoots producing roots and reduced callus formation at the base of these shoots. AgNO3 stimulated root emergence and enhanced root growth, while AVG increased the number of roots per shoot. CoCl2 slightly increased root number and rooting efficiency. These promotive effects may result from a reduction in ethylene concentration or inhibition of ethylene action. The results found in this study may be used to improve the rooting efficiency of other apple cultivars and rootstocks, and possibly of other plant species.

Malariotherapy for HIV patients.

The objective of this study was to determine whether HIV patients who undergo malariotherapy experience beneficial immunological change without iatrogenic complications. In an approved, prospective study, asymptomatic. HIV-positive patients were inoculated with P. vivax malaria and the malaria infection was allowed to run a predetermined course according to standard malariotherapy protocols and was cured with chloroquine. After termination of the malaria, the patients have been followed for 2 years with clinical and immunological monitoring. In the first two HIV-positive patients, CD4 counts rose significantly from pre-malaria measurements and remain at normal levels 2 years later without further treatment of any kind. During this time, the patients remained clinically well. An additional six HIV-positive patients were treated with malariotherapy and have remained clinically well during the first 6 months after treatment. These initial studies demonstrate malariotherapy results in an increase in CD4 counts of HIV-positive patients. Furthermore, these increases persist beyond the presence of malaria, for at least 2 years.

Consecutive evaluation of immunoglobulin M and G antibodies against hepatitis E virus.

Hepatitis E virus (HEV) infection is sporadic in the Guangzhou city southern China. However, the evaluation of antibodies to HEV during consecutive time periods after infection has not been reported. We utilized enzyme immunosorbent assay (ELISA) to defect IgM and IgG anti-HEV in consecutive serum specimens from patients with acute hepatitis E and compared that data with detection rates of IgM and IgG anti-HAV in patients with acute hepatitis A. IgM anti-HEV can be detected as early as 4 days after onset of disease symptoms in some patients. The detection rate of IgM anti-HEV is significantly higher in specimens collected within 4 weeks (95%) of onset than in those specimens collected 4 to 18 weeks after onset (67.6%) (P < 0.005). IgM anti-HEV had a similar pattern to IgM anti-HAV and can be used as a marker of acute HEV infection. In contrast with IgG anti-HAV, 56.8% of the specimens did not contain detectable levels of IgG anti-HEV (P < 0.005). One should be cautioned against making a diagnosis of HEV infection solely by the currently available assays for IgG anti-HEV. In conclusion, IgM anti-HEV can be used as a reliable and sensitive marker for recent HEV infection, but serum specimens should be collected within 4 weeks after onset of symptoms to avoid false-negative results. In contrast, we should be aware of the failure to develop IgG anti-HEV in some patients. These patients carry the risk of reinfection.

Alterations of the retinoblastoma gene in human prostate adenocarcinoma.

The loss or mutational inactivation of the RB1 tumor suppressor gene has been implicated in the development of a diverse group of human malignancies. However, the contribution of the RB1 gene alteration to human prostatic carcinogenesis has been poorly understood. Thus far, deletion of the promoter sequence and exon 21 from one primary tumor specimen and the alterations found in the cell line DU-145, are the only cases of RB1 mutations reported in human carcinoma of the prostate. This study was designed to determine whether alterations in the structure or expression of the RB1 gene occur in human prostate carcinoma, and to determine the nature of these changes and the frequency with which they occur. One hundred twelve primary prostate tumor tissues and four metastatic lesions were obtained immediately after surgical resection. The RB1 gene was characterized in 68 tumor DNA samples using Southern analysis and the PG3.8M or H3-8 probes. Band profiles were analyzed by scanning densitometry. Sixty-three tumor DNA samples were analyzed for defects in the RB1 promoter using polymerase chain reaction (PCR) and heteroduplex analysis. Alterations in the expression of exons 1-27 were analyzed in 79 primary and four metastatic tumor RNAs using RT-PCR. Three of 68 tumors were identified to have gross rearrangement of the RB1 gene or deletion of one allele. One of four stage D tumor specimens showed truncated RT-PCR products indicating an internal deletion of RB1 transcripts. In all, 14 of 83 (17%) specimens displayed abnormally low levels of RB1 mRNA expression. Furthermore, these alterations of RB1 expression showed a correlation with increasing tumor stage and grade. These results suggest alterations of RB1 mRNA expression occur more frequently in higher stages and grades of prostate cancer and, thus, may be contributing to the malignant progression of a subset of human prostate cancer.