Kallikreins as markers of disseminated tumour cells in ovarian cancer-- a pilot study.

BACKGROUND: Kallikreins are a family of secreted serine proteases, encoded by 15 genes which all localize in tandem on chromosome 19q13.4. Several members of this family have been previously associated with ovarian cancer. Kallikreins 6 (KLK6) and 10 (KLK10) are elevated in tumour cells, serum and ascites fluid of ovarian cancer patients and correlate with disease prognosis. Other kallikreins that have been related to ovarian cancer include KLK4, 5, 7, 8, 9, 11, 13, 14 and 15. We hypothesized that KLK6 and KLK10 can be utilized to monitor dissemination of ovarian cancer cells in blood and ascites fluid of ovarian cancer patients. METHODS: RNA was isolated by immunomagnetic separation of cancer cells and was amplified by RT-PCR. RESULTS: Screening for disseminated cancer cells in blood from 24 ovarian cancer patients, with RT-PCR for KLK6 mRNA, resulted in 75% positivity; however, this was not different from the positivity of normal controls. By utilizing KLK10 as a marker, the positivity of patients was 40% versus 20% of controls. Screening of ascites fluid of ovarian cancer patients revealed 90% positivity for KLK6 and KLK10 mRNA compared with 33% for other cancer types. Significant correlations were identified among mRNA of KLK4, 5, 6, 7, 8, 9, 10, 11, 13, 14 and 15 in cancer cells isolated from ascites fluid. CONCLUSION: Kallikrein expression by ovarian cancer cells is not specific enough for detecting disseminated disease. Kallikrein expression may have some value for differentiating ovarian cancer from other types of cancer or from non-malignant diseases that lead to ascites accumulation.     

Ethnic variation in kallikrein expression in nipple aspirate fluid

Socioeconomic factors cannot entirely explain why black women have an earlier age of breast cancer onset and higher mortality rates, stage for stage, than whites. We and others have shown that prostate-specific antigen [PSA, also known as human kallikrein (hK) 3] is a marker of breast as well as prostate cancer, that hK2 and hK3 are highly homologous at the DNA and protein level and that the level of progesterone, which appears to upregulate hK3, is influenced by ethnicity. We hypothesized that nipple aspiration fluid (NAF) hK2 and hK3 levels are (i) lower in black than white women; (ii) independently associated with breast cancer; (iii) influenced by menopausal status; and (iv) in combination are more informative about whether a woman has breast cancer than either marker alone. NAF was assayed for hK2 and hK3, and the results were stratified by ethnicity, presence or absence of cancer and menopausal status. Statistical analysis was then performed. When stratified by ethnicity, hK2 (p = 0.003) and hK3 (p = 0.027) levels in blacks were lower than in whites. hK2 was lower in premenopausal black than in white subjects, regardless of cancer status. Overall, hK2, hK3 and the ratio hK2/hK3 were lower in subjects with breast cancer than in normal subjects. hK3 was lower in postmenopausal women with breast cancer, regardless of ethnicity. hK2 and hK3 levels were higher in pre- than in postmenopausal whites. Using logistic regression and considering hK2, hK3, hK2/hK3 and ethnicity, hK3 was significantly associated with breast cancer in both pre- (p < 0.001) and postmenopausal women (p = 0.023). In conclusion, whereas hK2, hK3, hK2/hK3 and ethnicity are each significantly associated with breast cancer bivariately, after entering the strongest predictor, hK3, into a logistic regression model, no other variable accounted for additional variation, although this observation is preliminary due to the limited number of black subjects in the study.     

Long-term risk of re-treatment of patients using alpha-blockers for lower urinary tract symptoms

PURPOSE: The efficacy of alpha-adrenoceptor blockers for the treatment of lower urinary tract symptoms has been proven in numerous studies. However, little is known about the efficacy of the longer term. We investigated the long-term risk of re-treatment in patients using alpha-adrenoceptor blockers for lower urinary tract symptoms and the parameters that influence this risk. MATERIALS AND METHODS: We reviewed the files of 316 patients with lower urinary tract symptoms treated at our department with the alpha-blockers terazosin, alfuzosin or tamsulosin. Using followup data up to 3 years, we calculated re-treatment percentages in each treatment group. Using extended followup of 5 years, we calculated the predictive value of various baseline characteristics for re-treatment. RESULTS: The re-treatment rates were 27% for tamsulosin, 37% for alfuzosin and 49% for terazosin. The re-treatment rates of patients with mild, moderate and severe lower urinary tract symptoms were 27%, 33% and 70%, respectively. Patients with a maximum urine flow of less or more than 10 ml. per second had a re-treatment rate of 58% and 47%, respectively. Patients with a prostate volume of less or more than 40 ml. had a re-treatment rate of 48% and 72%, respectively. Patients who were urodynamically unobstructed versus obstructed patients had a re-treatment rate of 44% and 59%, respectively. CONCLUSIONS: Patients given alpha-blockers for lower urinary tract symptoms have a high risk of re-treatment. Tamsulosin has a markedly lower re-treatment percentage than alfuzosin and terazosin. Severe symptoms, poor urine flow, an enlarged prostate and urodynamically proven bladder outlet obstruction increase the risk of treatment failure. Preselection of the most suitable candidates for alpha-blockade may reduce this risk.     

Impact of cytogenetic and genomic aberrations of the kallikrein locus in ovarian cancer

The tissue kallikrein (KLK) genes are a new source for biomarkers in ovarian cancer. However, there has been no systematic analysis of copy number and structural rearrangements related to their protein expression. Chromosomal rearrangements and copy number changes of the KLK region were studied by FISH with protein levels measured by ELISA. Ovarian cancer and cell lines revealed the KLK region was subject to copy number imbalances or involved in unbalanced translocations and were associated with increased protein expression of KLKs 5, 6, 7, 8, 9, 10 and 11. In this initial study, we introduce the potential for long‐range chromosomal effects and copy number as a mechanism for the previously reported aberrant expression of many KLK genes in ovarian cancers.     

Familial aggregation of diabetes and hypertension in a case-control study of colorectal neoplasia

Familial aggregation of diseases potentially associated with metabolic syndrome (diabetes mellitus, hypertension, and cardiovascular diseases) was assessed in a colonoscopy-based case-control study of colorectal neoplasia in Toronto and Ottawa, Canada, in 1993-1996. Each familial disease was analyzed by logistic regression using generalized estimating equations. Case probands had incident adenomatous polyps (n = 172) or incident (n = 25) or prevalent (n = 132) colorectal cancer (CRC), while control probands (n = 282) had a negative colonoscopy and no history of CRC or polyps. Significant effect modification was evident in the data, with the strongest positive associations between familial diabetes and colorectal neoplasia among older probands with symptoms (parents: odds ratio (OR) = 2.4, 95% confidence interval (CI): 1.2, 4.8; siblings: OR = 5.8, 95% CI: 2.6, 13.3). Familial hypertension was also associated with colorectal neoplasia among probands with symptoms (OR = 1.7, 95% CI: 1.1, 2.6). In stratified analyses, familial diabetes, hypertension, and stroke were positively associated with adenomatous polyps in subgroups of probands who were older and/or had symptoms, while only familial diabetes was possibly associated with CRC. Associations in other proband groups may have been obscured by high cumulative incidence of parental CRC. Family studies are needed to understand the contribution of specific environmental and genetic factors in accounting for the disease aggregations.     

p53 gene mutation, tumor p53 protein overexpression, and serum p53 autoantibody generation in patients with breast cancer

OBJECTIVES: Autoantibodies against the p53 tumor suppressor protein have been detected in the serum of a proportion of patients with various cancers. The generation of such antibodies has been proposed to be due to either tumor p53 protein accumulation or to the type of p53 gene mutation. These hypotheses are examined in the present study. DESIGN AND METHODS: Using immunofluorometric assays, we studied 195 patients with primary breast cancer for the presence of p53 antibodies in serum and p53 protein accumulation in the corresponding tumor. Seventeen patients (9%) were p53 antibody-positive and 77 (40%) overexpressed p53. Ten of the 17 p53 antibody-positive patients had tumor p53 accumulation and 7 were negative for p53. Statistical analysis revealed a weak association between the presence of p53 antibodies and p53 protein accumulation (p = 0.05). Direct DNA sequencing of exons 1-11 of the p53 gene was performed for 16 p53 antibody-positive and 16 p53 antibody-negative patients. RESULTS: Five of the seropositive and eight of the seronegative patients had a p53 gene mutation. Four of the five mutations in the p53 antibody-positive patients affected a Tyr residue, whereas none of the gene abnormalities in the seronegative patients had such an effect. CONCLUSIONS: We conclude that p53 antibodies tend to develop in patients with tumor p53 accumulation, but p53 accumulation is neither sufficient nor necessary for the generation of the immune response. Further, p53 antibody-positive patients do not have higher frequency of p53 gene mutations than p53 antibody-negative patients, but the former patient group is associated with a Tyr substitution in the protein product.     

Human kallikrein 6 (zyme/protease M/neurosin): a new serum biomarker of ovarian carcinoma

BACKGROUND: There is an urgent need for discovery and validation of new serum biomarkers for ovarian carcinoma. Early diagnosis of ovarian cancer with serologic analysis may improve clinical outcomes through administration of effective treatment. Human kallikrein 6 (hK6, encoded by the KLK6 gene) is a serine protease of the kallikrein gene family. Recently, we were able to develop an immunofluorometric procedure for the quantitative measurement of hK6 in biologic fluids, including serum. METHODS: We have used an hK6-specific immunofluorometric assay to quantify hK6 protein in a large number of serum samples from normal individuals, as well as from patients with various malignancies. RESULTS: We report for the first time, significant increase of serum hK6 concentration in a large proportion of patients with ovarian carcinoma. The elevations of hK6 appear to be relatively specific for ovarian cancer because other malignancies did not cause any increase in the concentration of this biomarker in serum. Serial hK6 measurements appear to correlate with CA125 levels in patients monitored postsurgery. CONCLUSIONS: This is the first report describing significant elevations of hK6 concentration in serum of ovarian cancer patients. These data suggest that hK6 may represent a potential new biomarker for diagnosis and monitoring of ovarian carcinoma.