A Case of Acquired Hemophilia A: Usefulness of Various Methods for Judging Mixing Test Results for Monitoring the Effect of Immunosuppressive Therapy.

BACKGROUND: Measurement of FVIII inhibitor (FVIII INH) levels is important for determining the effect of immunosuppressive therapy on acquired hemophilia A (AHA). However, FVIII INH can only be measured at a limited number of laboratories, which means that there are delays in obtaining the results at many sites. METHODS: A series of mixing tests were carried out in a case of AHA, followed by comparison of various methods for judging the obtained results in association with a change of FVIII INH. The mixing test results were judged using the visual waveform pattern method and the index of circulating anticoagulant (ICA), as well as the difference between the APTT values of delayed-type and immediate-type waveforms (APTT D-I) as a numerical index. RESULTS: All examined judgment methods reflected the change in FVIII INH, but ICA and APTT D-I were particularly sensitive for capturing this. CONCLUSIONS: Our results suggest that a series of mixing tests are useful for rapid monitoring of the effect of immunosuppressive therapy on AHA.

Survivin plays as a resistant factor against tamoxifen-induced apoptosis in human breast cancer cells.

Tamoxifen has been the mainstay of endocrine therapy for estrogen receptor-positive breast cancer. However, approximately 40% of breast cancer patients do not respond to tamoxifen treatment. Further, most tumors eventually acquire tamoxifen resistance. Therefore, it is necessary to develop effective modalities to enhance the efficacy of tamoxifen in breast cancer treatment. In this study, we investigated the mechanism by which breast cancer cells develop resistance against tamoxifen from the viewpoint of tamoxifen-induced apoptosis. Overexpression of the anti-apoptotic molecule survivin rendered the human breast cancer cells MCF-7 resistant to tamoxifen-induced apoptosis. To examine whether the down-regulation of survivin can enhance tamoxifen-induced apoptosis, we introduced siRNA targeting the survivin gene (survivin-siRNA) into MCF-7 cells. Survivin-siRNA transfection not only induced apoptosis without tamoxifen treatment but also augmented the tamoxifen-induced apoptosis. We have previously demonstrated that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (HRIs), which are widely used to reduce the serum cholesterol levels in hypercholesterolemia patients, decreases survivin expression in colon cancer cells. To develop a pharmacological approach for improving the efficacy of tamoxifen treatment, we determined whether HRIs can enhance tamoxifen-induced apoptosis. Lovastatin, an HRI, down-regulated the expression of survivin protein in MCF-7 cells in a dose-dependent manner. In addition, the proportion of apoptotic cells induced by the tamoxifen and lovastatin combination was greater than the theoretical additive effect. These results suggest that survivin may function as a factor inducing resistance against tamoxifen-induced apoptosis, and the combined use of tamoxifen and HRI may be a novel approach to overcome tamoxifen resistance in breast cancer.

Diagnostic relevance of overexpressed mRNA of novel oncogene with kinase-domain (NOK) in lung cancers.

There have been no target molecules that have enabled us to diagnose lung cancer with high sensitivity and specificity even in its early clinical stages. A molecule termed novel oncogene with kinase-domain (NOK) was recently reported as a receptor protein tyrosine kinase that is expressed in some cancer cell lines and causes the transformation and progressive proliferation of normal cells. Therefore, NOK could be a possible candidate for a diagnostic marker for human cancers. We examined here, the degree of NOK mRNA expression in lung cancer tissues and compared it to that in non-cancerous tissues. More than 60% of non-cancerous samples (8/13) showed undetectable levels of mRNA. In contrast, NOK mRNA was detected in 97.6% (40/41) of lung cancer tissues, resulting in a sensitivity of 80.5% and a specificity of 92.3% that was estimated using the cutoff obtained from receiver operating characteristic curve analysis. Further, NOK mRNA expression was found to be elevated in 92.3% (12/13) of cancerous tissues when paired cancerous and non-cancerous tissues from identical patients were compared. There were no obvious correlations between clinicopathological factors and NOK mRNA expression; however, NOK mRNA was highly expressed even at the early clinical stages of the cancer. These results suggest that NOK mRNA might be a new tool to support the diagnosis of lung cancers, irrespective of the clinical stages.

Diagnostic relevance of overexpressed NOK mRNA in breast cancer.

A novel oncogene with a kinase domain (NOK), a receptor protein tyrosine kinase, has been reported to cause proliferation of normal cells, suggesting its possible use as a diagnostic marker in human cancer. To determine the significance of NOK expression in cancer cells, the effect of NOK inhibition was first examined on cell proliferation in vitro. The degree of expression in 52 clinical breast cancer samples was then correlated with clinical features. The transduction of NOK small inhibitory (si) RNA in T47D breast cancer cells decreased NOK mRNA expression, thereby inhibiting growth. When the mean expression in non-cancerous tissues from the same breast resection specimens +/-2SD was used as a cut-off value, 67.3% of breast cancers were positive for NOK expression - a higher positivity rate than that found for c-erbB2 (28.8%). NOK mRNA expression did not correlate with c-erbB2 expression, indicating the independence of NOK as a diagnostic marker. Furthermore, NOK mRNA was highly expressed even at early clinical stages. NOK mRNA might be an ideal target to support the diagnosis of breast cancer especially in tiny tumors in which the malignancy cannot be confirmed by other means.

Decreased gene expression for telomeric-repeat binding factors and TIN2 in malignant hematopoietic cells.

BACKGROUND: Details of mechanisms regulating telomere length are poorly understood in human hematopoietic cells. MATERIALS AND METHODS: Gene expression for TRFs and TIN2 was studied in hematopoietic cell lines, blood or bone marrow cells from acute leukemia and in normal leukocyte fractions. RESULTS: The telomeres were longest in normal leukocytes, shorter in patient samples and still shorter in malignant hematopoietic cell lines. TRF1 mRNA, TRF2 mRNA and TIN2 mRNA in three myeloblastic cell lines and six lymphoblastic cell lines were significantly less abundant than in the corresponding normal cell types. In patients with acute myeloid leukemia, expression of these gene was also less than in normal cells. In additional studies in culture, HL-60 cells with initially high telomerase activity and low expression of TRF mRNA and TIN2 mRNA differentiated into granulocytic and monocytic cells with low telomerase activity and high expression of these mRNAs. CONCLUSION: In hematopoietic carcinogenesis, gene expression for suppressors of telomerase activity, such as TRF and TIN2, is decreased. These genes might hold promise for gene therapy against cancer.

Down-regulation of TRF1, TRF2 and TIN2 genes is important to maintain telomeric DNA for gastric cancers.

BACKGROUND: The maintenance of telomeres may be required for long-term proliferation of tumors. Activity of telomerase, a ribonucleoprotein complex that elongates telomeres, has been found in almost all human tumors but not in adjacent normal cells. Several factors which regulate telomere length, TRF1 and 2, TIN2, tankyrase and Rap1, have been identified. TRF1, TRF2 and TIN2 are negative regulators of telomere length, while tankyrase and Rap1 act as positive regulators. In this study, we quantitated the mRNA of these five genes in gastric cancers to clarify the mechanism by which cancer cells maintain telomere length. MATERIALS AND METHODS: The expression of these five genes transcription was determined using a quantitative RT-PCR. RESULTS: TRF1, TRF2 and TIN2 mRNAs were significantly down-regulated in cancers compared to non-cancerous mucosa. Neither tankyrase nor Rap1 was upregulated in cancers. CONCLUSION: Down-regulation of TRF1, TRF2 and TIN2 gene expression may be important to maintain telomeres in gastric cancer.

A proapoptotic caspase recruitment domain protein gene, TMS1, is hypermethylated in human breast and gastric cancers.

BACKGROUND: Conway et al. demonstrated that methylation of the proapoptotic gene, TMS1, was observed in breast cancer cell lines and tissues, resulting in decreased TMS1 gene transcription. However, whether the TMS1 gene is hypermethylated in other cancers is uncertain. MATERIALS AND METHODS: The expression of TMS1 mRNA was determined by quantitative RT-PCR. Methylation of the TMS1 gene was detected using methylation-specific PCR followed by bisulfite-modification of DNA. RESULTS: Methylation of the TMS1 gene was observed in breast, gastric and colorectal cancer cells. Down-regulation of TMS1 gene transcription in colorectal cancer cells was restored by treatment with a demethylating agent. Methylation of the TMS1 gene was observed in 2 out of 19 breast cancer specimens and 1 out of 9 gastric cancers, but in none of 13 colorectal cancers. CONCLUSION: These results suggest a direct role for aberrant methylation of the TMS1 gene in the progression of breast and gastric cancer involving down-regulation of the proapoptotic TMS1 gene.

A novel gene containing PDZ and LIM domains, PCD1, is overexpressed in human colorectal cancer.

BACKGROUND: The process of colorectal cancer development involves accumulated genetic alterations affecting APC, K-ras and p53. A recently identified gene, PCD1, was reported to be up-regulated in human malignancies including colorectal cancers, but relationships between PCD1 gene expression and clinicopathological findings, as well as the timing of genetic alteration of PCD1 in colorectal cancer development, are not clear. To determine whether PCD1 contributes to colorectal cancer progression, we investigated the expression of PCD1 mRNA in human colorectal tissues. MATERIALS AND METHODS: The expression of PCD1 mRNA was determined by quantitative RT-PCR. The mutation of p53 was detected by a PCR-SSCP method. RESULTS: Up-regulation of PCD1 gene transcription was observed not in adenomas but in cancers compared to normal mucosa (p < 0.0001). Primary tumors with a mutation of p53 showed significantly greater PCD1 gene expression than tumors without such a mutation (p = 0.0134). CONCLUSION: The PCD1 gene may play a role in colorectal cancer development from adenomas.

Relevance of c-erbB2, PLU-1 and survivin mRNA expression to diagnostic assessment of breast cancer.

The positivity rates of mRNA expression in breast cancer of the tumor-related genes for c-erbB2, PLU-1 and survivin are unclear. We quantitatively analyzed tissue samples from 39 breast cancers and non-cancerous parts of the same specimens for the above three mRNAs using a TaqMan reverse transcription-polymerase chain reaction (RT-PCR). Using the mean + 2SD of non-cancerous sample as a cut-off value, the positivity rates of the tumors for c-erbB2, PLU-1 and survivin were 20.5%, 7.7% and 69.2%, respectively. Combining consideration of survivin with c-erbB2 and or PLU-1 increased the positivity ratio (survivin plus either of others, 76.9%; survivin plus both, 79.5%). Analysis by histological type indicated that survivin showed the highest positivity in ductal carcinoma and that survivin and PLU-1 showed the same positivity rate (40.0%) in the five carcinomas classified histologically as either solid-tubular or mucinous. Further, all cases that were positive for PLU-1 were negative for survivin. Survivin mRNA expression appeared more useful as a marker for diagnosis of breast cancer than c-erbB2 or PLU-1. However, PLU-1 appeared to vary independently of survivin, enhancing the usefulness of assays considering both in combination.

Specific overexpression of OLFM4(GW112/HGC-1) mRNA in colon, breast and lung cancer tissues detected using quantitative analysis.

Overexpression of the olfactomedin 4 (OLFM4(GW112,/hGC-1)) gene was recently reported to inhibit various apoptotic pathways and promote proliferation of cancer cells, suggesting that OLFM4 might serve as a diagnostic marker for human cancers. Therefore, we examined cancer-specific OLFM4 overexpression. OLFM4 mRNA was highly expressed in cancerous tissues obtained from the colon, breast and lung. Positivity for OLFM4 mRNA, defined as the mean + 2 SD in non-cancerous colon and breast tissues, was observed in 68 and 50% of the studied colon and breast cancer tissues. OLFM4 mRNA expression was not detected in non-cancerous lung tissues but was evident in 62% of the lung cancer tissues. On comparing paired samples, the expression of OLFM4 mRNA was observed to be elevated in 90, 69 and 85% of colon, breast and lung cancer tissues, respectively. OLFM4 mRNA expression was observed even in the early stages of each cancer type. The expression of OLFM4 mRNA did not correlate with that of the antiapoptotic molecule survivin, indicating that it can be used independently in cancer diagnosis. Combining OLFM4 and survivin resulted in higher positivity. Thus, OLFM4 mRNA might be a useful tool to support the diagnosis of cancer, irrespective of the clinical stages.

Olfactomedin 4 promotes S-phase transition in proliferation of pancreatic cancer cells.

Induction of olfactomedin 4 (OLFM4(GW112/hGC-1)) in cancer cells was recently reported to have a novel antiapoptotic action via binding to the potent apoptosis inducer GRIM-19. We sought to clarify undiscovered functions of constitutively expressed OLFM4 in cancer cells. OLFM4 mRNA was highly expressed in pancreatic cancer tissues. In PANC-1 cell cultures, expression was especially elevated during early S phase of the cell cycle. Transduction of small interfering RNA for OLFM4 to decrease mRNA expression caused time-dependent growth inhibition, with typical early S-phase arrest after 6 days. In addition, cell volume increased without increases in multinucleated cells, consistent with premitotic inhibition of DNA synthesis. Inhibition of OLFM4 mRNA expression by small interfering RNA did not promote apoptosis. Taken together, the results indicate that OLFM4 promotes proliferation of PANC-1 cells by favoring transition from the S to G(2)/M phase.