Identification of site-specific prognostic biomarkers in patients with oral squamous cell carcinoma.

The purpose of the present study was to identify site-specific prognostic biomarkers in patients with oral squamous cell carcinoma (OSCC). For this purpose, Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb and Bcl-2 were localized immunohistochemically in buccal mucosa carcinoma (n=74) and tongue carcinoma (n=61) patients. Expression of markers was compared between buccal mucosa and tongue carcinoma and assessed for their prognostic value in site-specific manner. On comparison, only cyclin D1 showed significant difference in expression with higher accumulation in tongue tumors (r=+0.177, p=0.039). Moreover, univariate survival analysis showed that in buccal mucosa patients, loss of p16 and overexpression of H-ras were significant prognosticators for relapse-free survival (RFS) and overall survival (OS), respectively. However, in Cox multivariate analysis, they lost their significance after adjusting for significant clinicopathological parameters. On the other hand, in tongue cancer patients, Cox multivariate analysis showed that for RFS, Stat3 and c-myc, and for OS, Stat3, Bcl-2 and p53 were significant prognosticators after adjusting for significant confounding factors. Our findings indicated that buccal mucosa and tongue carcinoma exhibit different biological behavior which is reflected in prognosis. Therefore, this approach might be helpful to precisely identify patients for more effectively tailored treatment strategy.

Molecular alterations in oral carcinogenesis: significant risk predictors in malignant transformation and tumor progression.

In this study an attempt was made to establish the significance of a battery of molecular alterations and thereby identify risk predictors in oral carcinogenesis. For this purpose, EGFR, Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67 and Bcl-2 were localized immunohistochemically in normal mucosa (n=12), hyperplasia (n=35), dysplasia (n=25), early stage carcinoma (n=65) and advanced stage carcinoma (n=70). Deregulation occurred at an early stage and the number of alterations increased with disease progression. Using multivariate logistic regression analysis, the significant risk predictor for hyperplasia from normal mucosa was Ki-67 (OR=5.75, p=0.021); the significant risk predictors for dysplasia from hyperplasia were EGFR (OR=12.96, p=0.002), Stat3 (OR=17.16, p=0.0001), p16 (OR=5.50, p=0.039) and c-myc (OR=5.99, p=0.052); the significant risk predictors for early stage carcinoma from dysplasia were p53 (OR=6.63, p=0.0001) and Rb (OR=3.81, p=0.056); and the significant risk predictors for further progression were EGFR (OR=5.50, p=0.0001), Stat3 (OR=4.49, p=0.0001), H-ras (OR=4.05, p=0.001) and c-myc (OR=2.99, p=0.015). Cyclin D1 holds a key position linking upstream signaling pathways to cell cycle regulation. Gene products of the mitogenic signaling pathway play an equally significant role as cell cycle regulatory proteins in the hyperplasia-dysplasia-early-advanced-carcinoma sequence and together may provide a reference panel of markers for use in defining premalignant lesions and predicting the risk of malignant transformation and tumor progression.

Stat3 expression in oral squamous cell carcinoma: association with clinicopathological parameters and survival.

The present study sought to explore the occurrence of signal transducer and activator of transcription 3 (Stat3) in patients with oral squamous cell carcinoma (n=135) and its potential relationship with clinicopathological parameters and survival. Stat3 expression was studied by immunohistochemistry. Cytoplasmic or nuclear localization of Stat3 was observed in 62% of patients, whereas only nuclear Stat3 expression was found in 44%. Stat3 positivity in early-stage patients was 45% compared to 79% in advanced-stage patients. However, early-stage Stat3-positive patients showed a gradual increase in staining intensity, with intense staining seen in 52% of the tumors compared to 18% in Stat3-positive advanced-stage patients, where a gradual decrease in intensity expression was observed (p=0.001). Stat3 showed a significant positive correlation with disease stage (p=0.001), nodal status (p=0.033) and tumor size (p=0.001). Multivariate survival analysis using the Cox proportional hazard regression model showed that nuclear Stat3 was a significant independent prognosticator for both relapse-free survival (p=0.014) and overall survival (p=0.042) in early-stage patients. Our results indicated that Stat3 activation is an early event in oral squamous cell carcinoma and represents a potential risk factor for poor prognosis in early-stage patients.

p53 expression in leukoplakia and carcinoma of the tongue.

There is growing interest in assessing multistep carcinogenesis and predicting its course using different molecular markers. TP53 is a tumor suppressor gene and appears to be one of the molecular targets of tobacco-related carcinogens in oral cancer. The present study evaluated the role of p53 expression in patients with leukoplakia and carcinoma of the tongue. p53 expression was studied by immunohistochemistry. All patients with leukoplakia of the tongue were male tobacco users. Nuclear staining of p53 was observed in 79% of those patients. Fifty percent, 25% and 4% of the patients expressed 1+, 2+ and 3+ nuclear staining, respectively. When leukoplakia patients were graded according to histopathology, 67% had hyperplasia and 33% had dysplasia. Nuclear p53 accumulation was 88% in hyperplasia and 62% in dysplasia. In patients with tongue cancer, nuclear accumulation of p53 was seen in only 19% of the tumors, with a staining intensity of 1+ in 13%, 2+ in 2% and 3+ in 4% of the tumors. The prevalence of nuclear p53 positivity (79%) was significantly higher in patients with leukoplakia than in patients with tongue cancer (19%; chi2 = 34.32, r = -0.45, df = 1, p = 0.0001; odds ratio (OR) = 16.66, 95% CI, 5.25-52.86). Therefore, leukoplakia patients who show p53 expression have a higher risk of developing tongue cancer than those who do not show p53 expression. As the percentage of positivity of nuclear p53 was very low, none of the clinicopathological parameters or disease status showed any significant association with it. The interesting finding is that none of the female cancer patients showed nuclear p53 expression. Therefore, p53 accumulation is believed to be an early event in neoplastic progression of the tongue.

Telomerase activity in breast cancer in Western India (Gujarat).

The purpose of this study was to examine the association of telomerase activity with clinical and histopathological prognostic variables in primary breast cancer (n=64). Telomerase activity in breast cancer was also compared with that in benign (n=10) and non-malignant tissues (n=8; post-lumpectomy tissues histopathologically defined as containing no residual tumor). The parameter was assessed using the Telomerase PCR ELISA kit. Values above OD 0.120 were considered positive. Estrogen and progesterone receptors (ER and PgR) were assayed by the dextran-coated charcoal method and levels >10 fmol/mg cytosol protein were taken as positive. Telomerase activity was detected in 20% and 50% of the patients with benign lesions and primary breast cancer, respectively, and in 50% of post-lumpectomy breast tissues histopathologically defined as containing no residual tumor. Telomerase activity was present in all stages of breast carcinoma and showed a significant inverse correlation with lymph node status (p=0.006), lymphatic invasion (p=0.035) and necrosis (p=0.033). Moreover, when stage II patients were grouped according to nodal involvement, a trend towards significance was observed (p=0.055). No correlation was observed with ER and PgR. The results of our study suggest that telomerase activity might be associated with the presence of cancer cells. Furthermore, telomerase activation may occur early in breast cancer and may be periodically downregulated during subsequent tumor progression.

Time to initiating highly active antiretroviral therapy among HIV-infected injection drug users.

OBJECTIVE: Studies have shown that HIV-infected injection drug users (IDUs) are less likely to receive antiretroviral therapy than non-drug users. We assess factors associated with initiating highly active antiretroviral therapy (HAART) in HIV-infected IDUs. METHODS: A cohort study of IDUs carried out between 1 January 1996 and 30 June 1999 at a community-based study clinic affiliated to the Johns Hopkins University, Baltimore, Maryland. The participants were a total of 528 HIV-infected IDUs eligible for HAART based on CD4+ cell count. The main outcome measure was the time from treatment eligibility to first self-reported HAART use, as defined by the International AIDS Society-USA panel (IAS-USA) guidelines. RESULTS: By 30 June 1999, 58.5% of participants had initiated HAART, most of whom switched from mono- or dual-combination therapy to a HAART regimen. Nearly one-third of treatment-eligible IDUs never received antiretroviral therapy. Cox proportional hazards regression showed that initiating HAART was independently associated with not injecting drugs, methadone treatment among men, having health insurance and a regular source of care, lower CD4+ cell count and a history of antiretroviral therapy. CONCLUSIONS: Self-reported initiation of HAART is steadily increasing among IDUs who are eligible for treatment; however, a large proportion continues to use non-HAART regimens and many remain treatment-naive. Although both groups appear to have lower health care access and utilization, IDUs without a history of antiretroviral therapy use would have more treatment options available to them once they become engaged in HIV care.

Molecular markers are predictors of recurrence and survival in patients with Dukes B and Dukes C colorectal adenocarcinoma.

PURPOSE: The goal was to investigate the prognostic value of various molecular markers like CEA, Cyclin D1, Bcl-2, c-Myc, p53, p21ras, Ki-67, CD44, Factor VIII-related antigen, cytokeratin-19, adenoma antigen, and prolactin in patients with Dukes B and Dukes C colorectal adenocarcinoma. METHODS: These molecular markers were localized immunohistochemically in nonmalignant (n = 36) and malignant (n = 98) diseases of the colorectum. Data were analyzed statistically using the SPSS software program. The patients with colorectal cancer were followed for a period of five years or their death within that period. RESULTS: The expression of carcinoembryonic antigen, Cyclin D1, Bcl-2, CD44, cytokeratin-19 and prolactin was significantly higher in malignant diseases (P < 0.05), whereas, p21ras was found to be significantly higher in nonmalignant diseases (P = 0.002) as compared with their respective counterparts. Besides Dukes stage, multivariate analysis indicated a significantly reduced relapse-free survival in patients expressing CD44 and cytokeratin-19 (P < 0.005). Similarly, besides Dukes stage, multivariate analysis indicated a significantly poor overall survival in patients expressing CD44, cytokeratin-19 and prolactin (P < 0.01). In patients with Dukes B disease, only cytokeratin-19 and CD44 expression attained statistical significance (P < 0.05), whereas in patients with Dukes C disease, CD44, p21ras- and c-Myc expression attained statistical significance (P < 0.018). Also, a multivariate analysis in relation to treatment given was performed using CD44 and cytokeratin-19. CONCLUSION: Besides Dukes stage, multivariate analysis of all the studied molecular markers showed that patients expressing CD44 and cytokeratin-19 had a significantly reduced relapse-free and poor overall survival. Moreover, patients expressing both these markers (CD44 and cytokeratin-19) had the lowest significant relative risk for developing recurrence than patients with both markers negative when treated with surgery followed by adjuvant chemotherapy as compared with patients treated with surgery alone. Thus, in patients with colorectal cancer, immunohistochemical localization of CD44 and cytokeratin-19 may be included as a part of routine pathologic evaluation along with conventional prognostic factors.

Ectopic production of prolactin by colorectal adenocarcinoma.

PURPOSE: This study assessed the role of prolactin in patients with Dukes B and C colorectal carcinoma. METHODS: Circulating prolactin and carcinoembryonic antigen were assayed using immunoradiometric assay and radioimmunoassay kits, respectively, in preoperative blood (n = 98) and tumor-draining venous blood (n = 34) samples of colorectal carcinoma patients. Immunohistochemical localization of prolactin (n = 98), carcinoembryonic antigen (n = 98), and prolactin receptors (n = 56) was performed. The expression of prolactin messenger ribonucleic acid (n = 50) and prolactin receptor messenger ribonucleic acid (n = 50) was studied by reverse transcriptase polymerase chain reaction. Further, prolactin amplimer was sequenced. RESULTS: Preoperative prolactin and carcinoembryonic antigen levels were significantly higher in patients with colorectal carcinoma than in controls (prolactin, P = 0.001; carcinoembryonic antigen, P = 0.0001). Univariate survival analysis showed that Dukes stage, histologic grade, and circulating prolactin were significant prognostic factors for determining overall survival (Dukes stage, P = 0.00001; histologic grade, P = 0.005; prolactin, P = 0.001). In multivariate analysis, besides Dukes stage, circulating prolactin emerged as the most significant independent prognostic factor influencing overall survival. Preoperative prolactin levels showed excellent significant correlation with response to therapy and progression of disease. A significant tenfold higher mean concentration of prolactin was observed in tumor-draining venous blood than in peripheral blood (P = 0.0001). Diffuse cytoplasmic staining for prolactin was seen in 51 percent (50/98) of the colorectal carcinomas. Prolactin messenger ribonucleic acid expression was seen in 88 percent (44/50) of the colorectal carcinomas. Sequence analysis of the 234-bp prolactin amplimer revealed that the sequence was homologous to exon 5 of pituitary prolactin messenger ribonucleic acid. CONCLUSION: These multiple approaches confirmed that prolactin is produced by colorectal carcinoma cells. Looking at its prognostic value and correlation with disease activity, it may provide new insights into treatment for patients with colorectal carcinoma.

Prolactin as a local growth promoter in patients with breast cancer: GCRI experience.

AIMS: The aim of this study was to evaluate the prognostic value of pre-operative prolactin (PRL) in conjunction with established prognosticators, and the risk of disease relapse in patients with early and advanced breast cancer. To confirm the hypothesis that PRL is produced by breast tumours molecular analysis of PRL, using immunohistochemistry, mRNA by RT-PCR and direct sequencing, was performed. Furthermore, presence of prolactin receptors (PRLR) was evaluated by immunohistochemical localization in these patients. METHODS: In 111 breast cancer patients, pre-operative PRL was determined by an immunoradiometric assay (IRMA) method. Immunohistochemical localization of PRL (IHL-PRL) and PRLR was performed on formalin-fixed, paraffin-embedded tissue sections. Expression of PRL mRNA was carried out by reverse transcriptase polymerase chain reaction (RT-PCR). RT-PCR PRL amplimer was sequenced and compared with human pituitary PRL amplimer. RESULTS: Fifty-eight per cent (64/111) of the patients had hyperprolactinaemia (PRL520.0 ng/ml). With increasing tumour size, a higher incidence of hyperprolactinaemia was noted which was statistically significant (r=0.34, P=0.0001). In stage III patients, and in node positive patients, the incidence of hyperprolactinaemia was significantly higher compared to their respective counterparts (stage II vs stage III, r=0.37, P=0.00006; node negative vs node positive, r=0.30, P=0.001). Hyperprolactinaemic patients had a significantly higher risk of developing recurrent/metastatic disease and a higher mortality risk as compared to patients with PRL <20.0 ng/ml. The multivariate survival analysis indicated that apart from disease stage, prognosis of patients with pre-operative hyperprolactinaemia was poorer than that of patients with PRL <20.0 ng/ml. Seventy-eight per cent (87/111) of the tumours showed positive immunoreactivity with PRL antibody indicating that PRL, or a similar molecule, is produced ectopically by breast tumours. PRL mRNA expression using RT-PCR confirmed the de novo synthesis of PRL. PRL mRNA expression was seen in 52% (33/63) of tumours. Sequence analysis of the 234 bp PRL amplimer revealed that the sequence was homologous to the sequence of exon 5 of human pituitary PRL mRNA. Furthermore, PRLR were present in 80% of tumours detected by immunohistochemical localization. A significant positive correlation was noted between IHL-PRL and PRLR (r=0.26, P=0.006). CONCLUSIONS: This multifaceted study of PRL suggests that breast cancer cells produce PRL and that this ectopically produced PRL may act as a major local growth promoter via autocrine and paracrine mechanisms. It may provide new insights into endocrine treatment of breast cancer.

Correlates of enrollment in methadone maintenance treatment programs differ by HIV-serostatus.

OBJECTIVES: To identify correlates of enrollment in methadone maintenance treatment programs (MMTP) among a prospective cohort of injection drug users (IDUs) in Baltimore, Maryland. METHODS: A total of 1480 IDUs undergoing semi-annual HIV tests and interviews were studied between 1994 and 1998, during which time a needle exchange program was introduced. Longitudinal analysis using generalized estimating equations was used to identify correlates of MMTP participation over time. RESULTS: Although similar proportions of HIV-seropositive and -seronegative IDUs enrolled in MMTP during follow-up (26 versus 22%, respectively), correlates of enrollment differed by HIV-serostatus. Among HIV-seropositive participants, older age [adjusted odds ratio (AOR, 1.37)] was associated with enrollment in MMTP. Among HIV-seronegative IDUs, factors associated with not enrolling in MMTP were being African American (AOR, 0.22) and having been recently incarcerated (AOR, 0.62) or homeless (AOR, 0.72). In both groups, females were twice as likely to be enrolled in MMTP, and those with Medicaid were 1.5 times more likely to be enrolled. When behavioral factors were lagged one visit, needle exchange program attendance was positively associated with MMTP enrollment among HIV-negative IDUs (AOR, 2.10); however, this association diminished significantly over time as dedicated treatment slots for needle exchange program participants became saturated. CONCLUSIONS: These findings underscore the need to improve access to MMTP, especially to certain subgroups such as African-Americans, the homeless, incarcerated and uninsured. Our data suggest that health care providers and needle exchange programs can facilitate enrollment into MMTP provided that adequate treatment slots are consistently available to this particularly vulnerable population.

Prognostic significance of immunohistochemically localized biomarkers in stage II and stage III breast cancer: a multivariate analysis.

BACKGROUND: The aim was to investigate the expression of a panel of biomarkers such as prolactin (PRL), p53, Bcl-2, c-erb B2, Ki-67, CD44, and factor VIII-related antigen (FVIII-RA) in primary tumors of stage II and stage III breast cancer and its correlation with disease prognostication. METHODS: The streptavidin-biotin peroxidase complex technique was used for the detection of these antigens. Cytoplasmic staining pattern was observed for PRL, Bcl-2, and Ki-67. Staining pattern for p53 was nuclear. Membranous and/or cytoplasmic staining was noted for c-erb B2 and CD44. Microvessel staining was noted for FVIII-RA. RESULTS: Of the 93 primary breast tumors analyzed, positivity for PRL was noted in 82%, for p53 in 56%, for Bcl-2 in 73%, for c-erb B2 in 68%, and for Ki-67 and CD44 in 78% each. The microvessel count (MVC) for FVIII-RA ranged from 0.0 to 29.0, with a median of 6.0, which was used as a cutoff. MVC > or = 6.0 was noted in 51% of breast tumors. With increasing tumor size, the higher frequency of positivity of MVC > or = 6.0 (P = .0001), CD44 (P = .001), PRL (P = .002), and c-erb B2 (P = .008), and higher frequency of Bcl-2 negativity (P = .033), was noted. In stage III patients, a higher positivity of the following biomarkers was noted, compared with stage II patients: MVC > or = 6.0 (P = .0004), PRL (P = .0002), c-erb B2 (P = .001), and CD44 (P = .005). Further, Bcl-2 positivity was significantly lower in patients with stage III disease compared with those with stage II disease (P = .024). In patients with nodal involvement, the frequency of c-erb B2 (P = .006), MVC > or = 6.0 (P = .011), and PRL (P = .032) was higher than in those without nodal involvement. Moreover, in these patients, with the increase in the number of involved lymph nodes, there was a significant increase in frequency of CD44+ (P = .0004) and PRL+ (P = .013) tumors. Abnormal expression of one biomarker was seen in 7% of tumors, of two biomarkers in 4%, of three in 15%, of four in 19%, of five in 28%, of six in 20%, and of all seven biomarkers in 7% of tumors. The frequency of an increasing number of biomarkers coexpressed was higher in stage III patients compared with stage II patients (P = .00003). In the total number of patients (n = 93), tumors with Bcl-2 negativity (P = .00001), MVC > or = 6.0 (P = .001), PRL positivity (P = .02), and CD44 positivity (P = .034) had a significantly poorer overall survival (OS) compared with their respective counterparts. In stage II patients (n = 40), only p53 expression was significantly associated with reduced relapse-free survival (P = .009) and OS (P = .040). In multivariate analysis, p53 expression was an independent prognostic factor that influenced relapse-free survival (P = .034) of stage II breast cancer patients. However, it failed to attain statistical significance for OS. In stage III patients (n = 53), tumors with Bcl-2 negativity (P = .0005) and MVC > or = 6.0 (P = .039) had a significantly poorer OS compared with their respective counterparts. In multivariate analysis of stage III patients, Bcl-2 was the only independent prognostic factor (P = .001) for predicting OS. There was a significant association between coexpression of the biomarkers and OS (P = .001). The OS rates decreased with the increase in number of abnormally expressed biomarkers. CONCLUSIONS: p53 expression in primary tumors was an independent prognostic factor that influenced relapse-free survival in patients with stage II disease. In stage III patients, lack of Bcl-2 expression was independently associated with a poor prognosis and, thus, may be an indicator of aggressive phenotype.

Prolactin as a local growth promoter in patients with locally advanced tongue cancer: GCRI experience.

BACKGROUND: The purpose of this study was to assess the role of prolactin (PRL) in men with locally advanced tongue cancer. METHODS: Circulating PRL was assayed immunoradiometrically in pretherapeutic and sequential blood samples of 99 patients with locally advanced tongue cancer. Patients were followed for 3 years or until their death within a stipulated time. Immunohistochemical localization of PRL was performed on formalin-fixed paraffin-embedded tissue sections. Tumoral prolactin receptors (PRLR) were estimated by ligand binding assay; the expression of PRL mRNA and PRLR mRNA were carried out by reverse transcriptase polymerase chain reaction (RT-PCR). Furthermore, PRL amplimer was sequenced and compared with human pituitary PRL amplimer. RESULTS: Pretherapeutic PRL levels were significantly higher in patients with locally advanced tongue cancer compared with controls (p =.01). Thirty-four percent (34 of 99) of the patients had hyperprolactinemia (PRL >/=15.0 ng/mL). Univariate survival analysis showed that patients with pretherapeutic hyperprolactinemia had a significantly shorter overall survival than patients with pretherapeutic PRL <15.0 ng/mL serum (p =.0009). In multivariate analysis, PRL emerged as the most significant independent prognostic factor influencing overall survival. Furthermore, changes in serial PRL levels showed excellent correlation with response to therapy and progression of disease. Forty-four percent (24 of 54) of the tumors showed positive immunoreactivity with PRL antibody, indicating that PRL or a molecule similar to it is produced by tongue tumors. PRL mRNA expression was seen in 85% (43 of 50) of the tumors and confirmed the de novo synthesis of PRL. Sequence analysis of the 234 bp PRL amplimer revealed that the sequence was homologous to exon 5 of pituitary PRL mRNA. The action of PRL is mediated by PRLR, and it was observed that the PRLR positivity by ligand binding assay was 33%. The expression of PRLR mRNA by RT-PCR showed two forms of PRLR mRNA (ie, intermediate form [500-600 bp] seen in 82% (41 of 50 ) of the tumors and the long form [800-900 bp] seen in 36% (18 of 50) of the tumors. In 82% (41 of 50) of the tumors, either the intermediate or long form was seen. CONCLUSIONS: This multifaceted study of PRL suggests that tongue cancer cells produce PRL, and this ectopically produced PRL might be acting as a major local growth promoter by means of autocrine and paracrine mechanisms. Looking at its prognostic value and correlation with disease activity, it may provide new insights into treatment of tongue cancer.

Overexpression of CD44: a useful independent predictor of prognosis in patients with colorectal carcinomas.

BACKGROUND: The goal was to investigate the potential correlation between overexpression of CD44, high microvessel count (MVC), and p21ras with length of relapse-free and overall survival in patients with colorectal adenocarcinomas. METHODS: CD44, factor VIII-related antigen (FVIII-RA), and p21ras were localized immunohistochemically in patients with colorectal adenomatous polyps (n = 8) and adenocarcinomas (n = 98). The correlation between the expression of CD44, MVC in the areas with highest density, and p21ras with relapse-free and overall survival time was investigated. Data were analyzed statistically using univariate and multivariate systems. RESULTS: In patients with adenomatous polyps, the positivity of CD44, FVIII-RA, and p21ras was 75%, 62%, and 88%, respectively. In patients with colorectal carcinomas the positivity of CD44 was 55%, and for p21ras it was 52%. The median of FVIII-RA was 4 MVC (range, 0.0 to 32.33). MVC was greater than 4 in 53% of the patients with colorectal carcinomas. In univariate analysis, a significantly longer relapse-free time (CD44: P = .0004; FVIII-RA: P = .0006) and overall survival time (CD44: P = .0001; FVIII-RA: P = .001) were observed for patients with CD44-negative tumors and MVC below 4 as compared to those with CD44-positive tumors and MVC greater than 4. Similar observations were noted in patients with Dukes B and C disease and the rectum as the site of tumor. In multivariate analysis, only CD44 correlated significantly with both relapse-free (P = .0003) and overall survival (P = .00001). CONCLUSION: Univariate analysis showed CD44 and MVC to be independent predictors of prognosis in colorectal carcinomas. Multivariate analysis showed that CD44 positivity was the most important indicator of an unfavorable prognosis for relapse-free and overall survival in patients with colorectal cancer. Thus, it can be deduced that whether CD44 is positive or negative in patients with colorectal cancer may have prognostic importance and in the future may be used as a factor in the pathologic evaluation of tumor specimens. This hypothesis needs to be tested prospectively in a larger number of patients.

Heterologous modules for efficient and versatile PCR-based gene targeting in Schizosaccharomyces pombe.

We describe a straightforward PCR-based approach to the deletion, tagging, and overexpression of genes in their normal chromosomal locations in the fission yeast Schizosaccharomyces pombe. Using this approach and the S. pombe ura4+ gene as a marker, nine genes were deleted with efficiencies of homologous integration ranging from 6 to 63%. We also constructed a series of plasmids containing the kanMX6 module, which allows selection of G418-resistant cells and thus provides a new heterologous marker for use in S. pombe. The modular nature of these constructs allows a small number of PCR primers to be used for a wide variety of gene manipulations, including deletion, overexpression (using the regulatable nmt1 promoter), C- or N-terminal protein tagging (with HA, Myc, GST, or GFP), and partial C- or N-terminal deletions with or without tagging. Nine genes were manipulated using these kanMX6 constructs as templates for PCR. The PCR primers included 60 to 80 bp of flanking sequences homologous to target sequences in the genome. Transformants were screened for homologous integration by PCR. In most cases, the efficiency of homologous integration was > or = 50%, and the lowest efficiency encountered was 17%. The methodology and constructs described here should greatly facilitate analysis of gene function in S. pombe.

Additional modules for versatile and economical PCR-based gene deletion and modification in Saccharomyces cerevisiae.

An important recent advance in the functional analysis of Saccharomyces cerevisiae genes is the development of the one-step PCR-mediated technique for deletion and modification of chromosomal genes. This method allows very rapid gene manipulations without requiring plasmid clones of the gene of interest. We describe here a new set of plasmids that serve as templates for the PCR synthesis of fragments that allow a variety of gene modifications. Using as selectable marker the S. cerevisiae TRP1 gene or modules containing the heterologous Schizosaccharomyces pombe his5+ or Escherichia coli kan(r) gene, these plasmids allow gene deletion, gene overexpression (using the regulatable GAL1 promoter), C- or N-terminal protein tagging [with GFP(S65T), GST, or the 3HA or 13Myc epitope], and partial N- or C-terminal deletions (with or without concomitant protein tagging). Because of the modular nature of the plasmids, they allow efficient and economical use of a small number of PCR primers for a wide variety of gene manipulations. Thus, these plasmids should further facilitate the rapid analysis of gene function in S. cerevisiae.

Coexpression of Bcl-2, c-Myc, and p53 oncoproteins as prognostic discriminants in patients with colorectal carcinoma.

PURPOSE: This study was undertaken to evaluate the clinical use of Bcl-2, c-Myc, and p53 oncoproteins, either singly or in combination, as prognostic discriminants relative to recurrence and overall survival in patients with Dukes B or C colorectal carcinoma. METHODS: Analyses were made on archival pathology tissues of 48 patients with colorectal cancer. The oncoproteins were localized using commercially available monoclonal antibodies: clone 124 for Bcl-2, 9E11 for c-Myc, and DO-7 for p53. The avidin-biotin peroxidase complex method was used. Patients were followed up for a period of 2 to 36 months. RESULTS: Expression of Bcl-2 and c-Myc was cytoplasmic, whereas nuclear p53 immunoreactivity was localized in the tumor cells. Sixty percent (29/48), 65 percent (31/48), and 37 percent (18/48) of the tumors showed overexpression of Bcl-2, c-Myc, and p53 oncoproteins, respectively. Fifty-four percent (18/33) and 100 percent (9/9) of moderately and poorly differentiated tumors, respectively, were positive for Bcl-2 (P < 0.01). No such correlation was noted for c-Myc and p53 oncoproteins. Univariate analysis showed that patients with Bcl-2 and c-Myc overexpression were associated with poorer overall survival than patients with Bcl-2-negative (P < 0.0124) and c-Myc-negative (P < 0.036) tumors. In addition, when patients were subgrouped according to Dukes stage, a statistically significant poorer overall survival was observed in Dukes C patients with Bcl-2-positive tumors (P < 0.017). Furthermore, multivariate analysis revealed that coexpression of three oncoproteins was predictive of a worse prognosis than for those individuals expressing none of the oncoproteins (P < 0.031) and only one positive oncoprotein (P < 0.014). CONCLUSION: These findings suggest that oncoprotein coexpression possesses significant prognostic and potential therapeutic value; incorporation of molecular markers into future prospective randomized trials is advisable.

Clinical significance of p53, nm23, and bcl-2 in T3-4N1M0 oesophageal carcinoma: an immunohistochemical approach.

BACKGROUND AND OBJECTIVE: The purpose of this retrospective study was to test whether the expression of p53, nm23, and bcl-2 in T3-4N1M0 oesophageal carcinoma is associated with patient survival. METHODS: Immunohistochemical localisation of p53, nm23, and bcl-2 was performed on formalin-fixed, paraffin-embedded tissue sections (N = 46). The observed range of follow-up period was 0.2-24.0 months with a median of 11.0 months. A total of 85% (39/46) of the patients died within 24.0 months, which could be due to advanced disease at presentation. The immunohistochemical signal was expressed as the proportion of positive cells. The immunostaining for p53 was nuclear, whereas that for nm23 and bcl-2 was cytoplasmic in the neoplastic cells. RESULTS: p53 was expressed in 70% (32/46) of cases; nm23 in 29% (13/45), and bcl-2 in 67% (29/43) of tumours. The univariate analysis showed that the expression of two markers, i.e., expression of p53 and absence of nm23 were independently associated with unfavourable overall survival time. Despite a small number of patients treated with adjuvant therapy, we observed that tumours positive for p53 had an unfavourable prognosis when compared with tumours negative for p53. CONCLUSIONS: Our preliminary findings suggest: expression of p53 and nm23 negativity may be related to an unfavourable prognosis in patients with advanced oesophageal carcinoma.

Node negative breast carcinoma: hyperprolactinemia and/or overexpression of p53 as an independent predictor of poor prognosis compared to newer and established prognosticators.

The purpose of this study was to investigate a prognostic indicator that can differentiate node negative breast cancer patients (N = 39, T2N0M0) with high risk and low risk for the development of recurrence or metastases. Preoperative plasma prolactin (PRL) was estimated by radioimmunoassay. The expression of PRL, p53, nm23, and c-erbB2 was investigated by immunohistochemical (IHC) localization; cathepsin D (CD, Enzyme Linked Sorbant Assay) and estrogen- and progesterone-receptors (ER and PR, Dextran coated charcoal method) were estimated in the tumor cytosols. The follow-up period was 2-6 years. Statistical comparisons were made between each marker for relapse-free survival (RFS) and overall survival (OS). Of the 39 patients, 18 had hyperprolactinemia (PRL > 20.0 ng/ml plasma), whereas overexpression of p53 was observed in 55% (17/31) tumors. These were independently and in combination associated with a reduced RFS and OS. The rest of the investigated markers did not show promising results. Hyperprolactinemia and/or overexpression of p53 were associated with aggressiveness of the tumor, early disease relapse or metastases, and poor OS in patients with node negative breast cancer. These two markers may enhance our ability to identify node negative breast cancer patients with aggressive tumors, for whom the use of adjuvant chemo and/or endocrine therapy is unequivocally justified.

Prognostic value of insulin-like growth factor-1 receptors in patients with colon/rectal cancer: correlation with plasma prolactin.

Prognostic value of IGF-1 receptors (IGF-1R) was evaluated and compared with circulating prolactin (PRL) in 59 patients with Dukes B or C colon/rectal cancer. IGF-1R was estimated by radioligand binding assay and PRL was estimated by immunoradiometric assay. Eighty-five percent (50/59) of patients had IGF-1R- tumours while IGF-1R positivity was observed in only 15% (9/59) of patients. None of the clinicopathological parameters showed any association with IGF-1R status. No significant difference was observed in overall survival period between patients with IGF-1R+ tumours and those with IGF-1R- tumours. However, a significant difference in overall survival time was observed between patients with PRL < 20.0 and > 20.0 ng/ml plasma (X2 = 4.70, df = 1, P < 0.05). In bivariate analysis, patients with IGF-1R- tumours and concomitant hyperprolactinemia had unfavourable prognosis compared to their counterpart (X2 = 4.21, df = 1, P < 0.05). We conclude that there was a trend of better overall survival in patients with IGF-1R+ tumours, and PRL < 20.0 ng/ml plasma when compared to patients with IGF-1R- tumours, and PRL > 20.0 ng/ml plasma. Further, IGF-1R negativity in conjunction with hyperprolactinemia could be used as an indicator of unfavourable prognosis in patients with Dukes B or C colon/rectal cancer.

Prolactin: its role in advanced tongue cancer.

Serum prolactin was measured pretherapeutically and sequentially thereafter using immunoradiometric assay method in 37 male patients with advanced tongue cancer and compared with 23 healthy, age-matched controls. Prolactin levels were correlated with age, various clinicopathologic parameters, overall survival, and patients with response and those with progressive disease. Patients with advanced tongue cancer had higher prolactin levels than controls (P < 0.02), but intergroup variation in prolactin was not observed when considering the age, site of the lesion, disease stage, histologic grade, and keratin. Of the patients, 30% had hyperprolactinemia (prolactin > 15.0 ng/ml). To assess the prognostic significance of pretherapeutic prolactin level, the patients were divided according to the cutoff level of prolactin (15.0 ng/ml). Hyperprolactinemic patients had more unfavourable prognosis than patients with prolactin < 15.0 ng/ml (X2 = 2.91, df = 1, P < 0.0037). In monitoring disease course, patients who responded to treatments had decreased prolactin levels at the end of 18 months as compared to their pretherapeutic levels (P < 0.01). In patients who subsequently developed progressive disease within 18 months, prolactin levels reduced initially at response, whereas with disease progression, prolactin levels increased significantly (P < 0.05). The positive and negative predictive value of prolactin was 100%. Immunohistochemical localization confirmed the ectopic production of prolactin by tongue tumors. In conclusion, our data indicate that hyperprolactinemia may be an independent predictor of short-term prognosis; circulating prolactin may be used as a marker for monitoring disease course in patients with advanced tongue cancer, and prolactin is produced ectopically by tongue tumors.