Automutanolysin disrupts clinical isolates of cariogenic streptococci in biofilms and planktonic cells.

INTRODUCTION: Dental caries remains one of the most common chronic infectious diseases throughout the world. The formation of dental plaque is one of the caries risk factors. As a consequence, the removal of plaque may reduce the incidence of caries development. We identified an autolysin produced by Streptococcus mutans named auto-mutanolysin (Aml). Aml selectively lyses S. mutans and Streptococcus sobrinus. The specificity towards these cariogenic bacteria suggests that Aml may be used to prevent dental caries. Here, with the aim towards therapeutic application, we investigated the lytic activity of Aml against clinical isolates of S. mutans and S. sobrinus using planktonic cells and biofilms. METHODS: Planktonic cell suspensions and biofilms of clinically isolated streptococci were treated with Aml in the absence or the presence of Triton X-100. The lytic activity of Aml was monitored as the change in turbidity. The disruption of biofilms was evaluated by detecting the released DNA by polymerase chain reaction and observing the alteration of optical density of treated biofilms. RESULTS: Triton X-100 enhances the lytic ability of Aml. Using planktonic cells, Aml had various lysis levels against clinical strains. Repeated Aml treatment showed disruption of the biofilm using the representative clinical strains. CONCLUSION: Our study demonstrates that Aml has an ability to lyse planktonic and biofilm cells of clinically isolated mutans streptococci in the presence of Triton X-100. These results suggest the possibility of using Aml as an alternative or additional approach for caries prevention.

Clinicopathological significance of fragile histidine triad transcription protein expression in breast carcinoma.

The fragile histidine triad (Fhit) gene, which is frequently lost in many cancers, was identified as a candidate tumor suppressor gene at chromosome 3p locus 14.2. Loss of Fhit expression is an important step in tumor progression from premalignancy, to in situ, to invasive breast carcinoma. To determine whether the absence of Fhit protein correlates with other established pathological-clinical parameters or prognosis, we assessed Fhit expression using immunohistochemistry in 166 invasive breast carcinomas. Lost or significantly decreased Fhit protein expression was identified in 70 cases (42.2%). Fhit expression was inversely correlated with histological grade (P < 0.0001), negative estrogen receptor status (P = 0.0016), p53 overexpression (P = 0.0040), and tumor proliferation activity (P = 0.0006). Survival curves determined by the Kaplan-Meier method and univariate analysis demonstrated that reduced expression of Fhit was associated with a poor outcome (P = 0.0086, by log-rank test). Multivariate analysis using the stepwise Cox proportional hazard model showed that lymph node metastasis was related to poor survival rates; in addition, patients with loss of Fhit expression still tended to have poor survival (P = 0.0563). Therefore, loss of Fhit expression is associated with higher malignant phenotypes and appears to be a prognostic factor in breast carcinoma.

A mathematical model of axillary lymph node involvement considering lymph node size in patients with breast cancer.

BACKGROUND: Surgical sampling for assessing axillary status has not been considered as a well defined surgical procedure. We have reported that MRI is a good instrument for assessing lymph node size and identifying lymph node position. We also developed a mathematical model that takes into consideration the size of axillary lymph nodes, and retrospectively determined the number and size of the axillary lymph nodes that need to be sampled from level I-II to achieve a greater than 90% probability of metastasis detection after surgical sampling, with the future aim of using MR-axillography to assess lymph node size. METHODS: One thousand nine hundred and thirty four lymph nodes from 102 level I-II dissections performed on T1 and T2 breast cancer patients with nodal metastases were examined histologically and the greatest long-axis dimension on histologic slides was measured. RESULTS: This model permitted determination of the cutoff level necessary for an expected probability of detection of metastasis of over 90%. The cutoff level, regardless of tumor size, is a maximum of 6 nodes removed from level I-II in which the greatest long-axis measurement is greater than or equal to 6 mm. The cutoff level in patients with macrometastatic nodes is a maximum of 3 or 4 nodes in which the long-axis dimensions are greater than or equal to 9 or 7 mm, respectively, removed from level I-II. CONCLUSIONS: This model showed that surgical sampling on the basis of lymph node size might have good potential to detect lymph nodes metastases.

Pamidronate-induced remission of pain associated with hypertrophic pulmonary osteoarthropathy in chemoendocrine therapy-refractory inoperable metastatic breast carcinoma.

We describe an extremely rare case of a woman with pulmonary metastatic disease from breast cancer, who presented with features of hypertrophic pulmonary osteoarthropathy (HPOA). Pain associated with HPOA may be extremely disabling and resistant to treatment. Treatment with pamidronate, an inhibitor of osteoclastic bone resorption, given every 2 weeks by i.v. drip infusion, led to rapid disappearance of uncontrolled pain caused by HPOA.

Hypermethylation does not account for the frequent loss of the retinoic acid receptor beta2 in breast carcinoma.

Hypermethylation of the retinoic acid receptor (RAR) beta2 has been detected in breast cancer cell lines and is known to repress the level of RAR beta2 transcription. RAR beta2 mRNA loss has often been detected in breast cancer tumors, whether promoter region methylation of the RAR beta2 gene accounts for its loss is still unknown. We examined the methylation status of RAR beta2 in breast tumors; 21 out of 50 (42%) breast tumors showed RAR beta2 hypermethylation. RT-PCR analysis showed a complete loss of RAR beta2 mRNA expression in 15 out of 43 (35%) breast tumors. No correlation between the hypermethylation and RAR beta2 loss was found, suggesting that hypermethylation is not fully responsible for the loss of expression of the RAR beta2 gene during breast tumorigenesis.

Prognostic significance of BRCA1 expression in Japanese sporadic breast carcinomas.

BACKGROUND: BRCA1 is a tumor suppressor gene that is responsible for hereditary breast and ovarian carcinoma syndrome. The primary objective of the current study was to investigate the influence of BRCA1 expression on the prognoses of sporadic breast carcinomas. METHODS: A cohort of 175 Japanese women with invasive breast carcinoma who had no family history in first-degree relatives was studied. Expression of BRCA1 was determined by an immunohistochemical procedure in which the MS110 monoclonal antibody was used. Kaplan--Meier and Cox proportional regression survival analyses were used to compare negative and positive BRCA1 patients. RESULTS: One hundred fifteen (65.7%) of the 175 specimens showed positive BRCA1 staining (> 10% cells were immunoreactive). During a median follow-up of 4.4 years, negative BRCA1 patients had worse disease free survival than positive BRCA1 patients (35 % vs. 7%, respectively; P < 0.0001). BRCA1 expression was significantly inversely correlated with histologic grade (P < 0.0001) but not with lymph node status or other conventional prognostic markers. In multivariate analysis using the Cox regression model, positive BRCA1 emerged as an independent prognostic indicator for disease free survival. CONCLUSIONS: The results of this study suggest that BRCA1 may be a valuable marker for identifying women with sporadic breast carcinoma at high risk of developing recurrence, and who may be candidates for trials investigating new therapies in combination with standard adjuvant therapy.

Correlation between nuclear grade and biological prognostic variables in invasive breast cancer.

BACKGROUND: Grading of carcinomas is an estimation of differentiation. Nuclear grading is the cytological evaluation of tumor nuclei in comparison with the nuclei of normal mammary epithelial cells. Because nuclear grading does not involve an assessment of the growth pattern of the tumor, it applies not only to invasive ductal carcinoma but also to other subtypes of breast carcinoma. METHODS: A total of 215 primary breast carcinomas obtained from the Affiliated Kihoku Hospital of Wakayama Medical College were enrolled in our present study. Nuclear grade was evaluated according to the criteria of the National Surgical Adjuvant Study of Breast Cancer (NSAS-B) protocol. Immunohistochemistry was also performed to determine Bcl-2, p53, c-erbB-2, estrogen receptor (ER) and MIB-1 expression in paraffin-embedded tissues for all cases. RESULTS: Thirty-two (14.9%) of the patients were graded as 1,124 (57.7%) as 2, and 59 (27.4%) as 3. Nuclear grade displayed a negative correlation with Bcl-2 expression (r=-0.308, p<0.0001), and a positive correlation with c-erbB-2 overexpression (r= 0.172, p=0.0117) and tumor proliferative index labeling by MIB-1 (r=0.485, p<0.0001). CONCLUSIONS: These results imply that nuclear grade is related to the characteristics of tumor biology, indicating that the morphology and biology of breast cancer are tightly linked. Our present results also suggest that adding the nuclear grade to the pathological diagnosis of invasive breast carcinoma may be clinically useful for predicting tumor behavior, for example aggressiveness, and for prognostication.

Biallelic inactivation of retinoic acid receptor beta2 gene by epigenetic change in breast cancer.

A growing body of evidence supports the hypotheses that retinoic acid receptor beta2 (RAR beta2) is a tumor suppressor gene. Although the loss of RAR beta2 expression has been reported in many malignant tumors, including breast cancer, the molecular mechanism is still poorly understood. We hypothesized that loss of RAR beta2 activity could result from multiple factors, including epigenetic modification and loss of heterozygosity (LOH). Using methylation-specific polymerase chain reaction and LOH analysis, we found that biallelic inactivation via epigenetic changes of both maternal and paternal alleles, or epigenetic modification of one allele combined with genetic loss of the remaining allele, could completely suppress RAR beta2 expression in breast cancer. Thus, it is possible that substantial numbers of human cancers arise through suppressor gene silencing via epigenetic mechanisms that inactivate both alleles. Because of this, chromatin-remodeling drugs may provide a novel strategy for cancer prevention and treatment.

Allelic loss of chromosome 3p24 correlates with tumor progression rather than with retinoic acid receptor beta2 expression in breast carcinoma.

A tumor suppressor gene. retinoic acid receptor (RAR) beta2, has been mapped to chromosome 3p24, a region where loss of heterozygosity (LOH) has been observed commonly in carcinomas of various tumor tissues. RAR beta2 expression is reduced or lost in many malignant tumors including breast cancer, however, whether LOH accounts for the loss of expression of RAR beta2 in breast cancer is unknown. We, therefore, assessed LOH on chromosome band 3p24 to correlate it with RAR beta2 expression and other established prognostic parameters in 52 breast carcinomas. Based on three microsatellites, D3S 1283, D3S 1293 and D3S 1286. all of the tumors were informative, of these, 12 (23%) exhibited LOH. RAR beta2 expression was lost in 42% (19/45) of these samples. We found that LOH on chromosome band 3p24 was not correlated with loss of RAR beta2, but correlated with higher histological grade, p53-positivity, and loss of estrogen and progesterone receptors. Our findings suggest that LOH of the RAR beta2 gene does not account for the frequent loss of RAR beta2 expression in breast cancer but the genomic structural alteration at or close to the RAR beta2 gene locus are likely to be associated with tumor progression and/or loss of hormonal dependency.

Paclitaxel-induced remission in docetaxel-refractory anthracycline-pretreated metastatic breast cancer.

Paclitaxel and docetaxel are excellent agents with a high antitumor effect for the treatment of previously anthracycline-exposed metastatic breast cancer. There has been no standard treatment for patients who undergo therapy of a taxan-resistant metastatic breast cancer. Paclitaxel has partial non-cross-resistance in vitro with docetaxel in inhibiting microtubule disaggregation. We present the case of a patient with docetaxel-refractory anthracycline-pretreated metastatic breast cancer who achieved remission with paclitaxel.

Thymidine phosphorylase expression correlates with tumor differentiation and Bcl-2 in invasive breast cancer.

BACKGROUND: Angiogenesis plays an important role in the growth and metastasis of solid tumors. Several angiogenic factors have been identified, and thymidine phosphorylase (TP) is thought to be one such factor. To date, little information is available on the relationship between TP and other clinicopathological variables. METHODS: Formalin-fixed, paraffin-embedded materials from 116 primary breast carcinomas were used. The expression of TP, estrogen receptor, Bcl-2, Bax, p53, c-erbB-2 and MIB-1 was examined by immunohistochemical methods. RESULTS: Nuclear and/or cytoplasmic TP expression was observed in the neoplastic cells, and accentuation of TP was often present at the infiltrating tumor edge and intraductal spread region. Tumor cell TP expression was significantly inversely correlated with histological grade (p< 0.05) and positively correlated with Bcl-2 expression, but no association with other tumor variables was found. CONCLUSIONS: TP is associated with Bcl-2 expression and tumor differentiation in breast cancer. TP may be a new prognostic parameter for breast cancer.

Expression of Bcl-2 but not Bax or p53 correlates with in vitro resistance to a series of anticancer drugs in breast carcinoma.

Programmed cell death is an important determinant of the response to chemotherapy. Among the factors controlling this process, a significant role is played by bcl-2, bax and p53. The in vitro chemosensitivity of the 177 breast carcinomas was assessed by the histoculture drug response assay (HDRA) using mitomycin C (MMC), 5-fluorouracil (5-Fu), adriamycin (ADM), cisplatin (CDDP), and cyclophosphamide (CPA). The susceptibility of Bcl-2-negative tumors to all the drugs killing was significantly higher than that of Bcl-2-positive tumors. No relationship between Bax or p53 immunoreactivity and sensitivity for any of anticancer drugs studied was demonstrated. Immunohistochemical results regarding Bcl-2 are promising in the evaluation of the sensitivity of cancer cells to a series of anticancer drugs and might be therapeutically useful as an indicator of response to adjuvant chemotherapy for breast cancer.

Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report.

This 68-year-old woman underwent a distal gastrectomy for gastric cancer in August 1994. A presumed meningioma of the falx was found incidentally on a staging examination of the gastric cancer, but the meningioma was not treated with surgery. Instead, after gastrectomy the patient received tegafur as adjuvant chemotherapy until February 1996, when she was readmitted to the hospital because of loss of appetite and emaciation but with no recurrence of the gastric cancer. A computerized tomography scan obtained during this second admission showed no change in the meningioma. To improve her general condition, tegafur was discontinued and she was started on a course of the antiestrogen agent mepitiostane. Administration of mepitiostane for approximately 2 years resulted in a marked regression (73%) of the meningioma. This is the first reported case of a presumed meningioma that regressed as a result of use of the antiestrogen agent mepitiostane.

[Pain relief with alendronate therapy in a breast cancer patient with bone metastasis].

A 66-year-old woman developed a bone metastasis from breast cancer to the sternum in September, 1997. She received alendronate therapy, consisting of biweekly intravenous administrations of 10 mg-alendronate 6 times and monthly 20 mg-alendronate infusions 15 times. The first alendronate administration markedly alleviated her bone pain. She obtained complete pain relief after the 4th alendronate infusion. However, an elevation of tumor marker levels in serum without any pain increase forced us to treat her with medroxyprogesterone acetate and doxifluridine in addition to the alendronate therapy. With these therapies, she has shown an objective response (PR) of the bone metastasis for 8 months. In conclusion, alendronate therapy was effective against bone pain due to metastasis of breast cancer.

Novel polymorphisms of prostate-specific antigen (PSA) gene associated with PSA mRNA expression in breast cancer.

A growing body of evidence suggests that prostate-specific antigen (PSA) is a novel prognostic factor for breast cancer. The molecular mechanism of variant PSA expression in breast cancer has remained poorly understood in spite of intensive research. Previous studies have shown that the coding region of the PSA gene is not a target for mutations in prostate cancer and breast cancer. The purpose of this study was to analyze genetic variations in the promoter region of the PSA gene, and to detect whether such variations are correlated with PSA mRNA expression in breast tumors. We identified two polymorphisms in the proximal promoter region of the PSA gene. These polymorphisms are located at positions -252 (G or A) and -205 (A or AA), and generate three genotypes. The genotypes were associated with PSA mRNA expression. Our findings suggest that these polymorphisms identified in the proximal promoter region may affect the transcriptional activity of PSA.

Overexpression of p27 protein in human breast cancer correlates with in vitro resistance to doxorubicin and mitomycin C.

BACKGROUND: The cycle regulatory protein p27, an inhibitor of cyclin-dependent kinase (CDK), has been attributed a role in resistance to cancer chemotherapy. However, the predictive value of p27 for chemosensitivity of breast cancer is still unclear. We therefore analyzed the in vitro chemosensitivity to a series of anticancer agents in fresh breast cancer specimens and correlated it with the respective expression levels of p27. MATERIALS AND METHODS: The expression of p27 protein was examined immunohistochemically in 119 patients with primary breast cancer. The in vitro chemosensitivity was assessed by the histoculture drug response assay (HDRA) using mitomycin C (MMC), 5-fluorouracil (5-Fu), Doxorubicin (DXR), cisplatin (CDDP) and cyclophosphamide (CPA). RESULTS: Fifty-six (47%) of the 119 patients demonstrated p27 overexpression. The susceptibility of DXR and MMC in tumors with high p27 expression was significantly higher than that in tumors with low p27 expression. CONCLUSION: Immunohistochemical results regarding p27 might be therapeutically useful as an indicator of response to DXR and/or MMC based adjuvant chemotherapy for breast cancer.

[Study on the safety of rapid infusion and the efficacy of incadronate against bone metastasis of breast cancer].

To assess the safety of rapid infusion of incadronate and its efficacy against bone metastasis of breast cancer, we conducted a trial using incadronate therapy for breast cancer patients with bone metastasis. Of the 12 patients, 6 had undergone pamidronate or alendronate therapy. Rapid infusion of incadronate consisted of administration of 10 mg incadronate diluted in 100 ml saline in 30 minutes, and was repeated every two weeks. Each patient underwent 2 to 20 incadronate administrations. With the incadronate therapy, no patients showed hypocalcemia, but 3 patients showed asymptomatic hypophosphoremia. Of the 11 patients with bone pain, 5 patients (45%) experienced pain relief. A decrease in tumor marker levels in serum was found in 5 (56%) of the 9 patients with elevated marker levels. The side effects of incadronate administration were general fatigue (25%), pyrexia (17%) and transient pain increase (17%), but no renal dysfunction was found. In conclusion, rapid infusion of incadronate was a safe treatment and the incadronate therapy was effective against bone metastasis of breast cancer.

[Breast cancer with osteoblastic bone metastasis treated successfully with bisphosphonate: a case report].

A 52-year-old woman with painful osteoblastic bone metastasis received pamidronate therapy which resulted in marked pain relief with a normalization of elevated tumor marker levels. However, the patient complained of increased pain after the 26th pamidronate infusion. Although a change from pamidronate to alendronate therapy did not relieve bone pain, a second change from alendronate to incadronate therapy resulted in pain relief with a decrease in re-elevated tumor marker levels. These findings suggest that bisphosphonate therapy is effective against osteoblastic bone metastasis in breast cancer, and that sequential therapy with bisphosphonates may be effective against bone metastasis in some cases.

Expression of Bcl-2, but not Bax, correlates with estrogen receptor status and tumor proliferation in invasive breast carcinoma.

Bcl-2 and Bax have been demonstrated to be associated with apoptosis in breast carcinoma, and the ratio between Bax and Bcl-2 seems to be an important determinant of cellular sensitivity to induction of apoptosis. However, little information is available on the relationship between Bcl-2, Bax and the proliferative activity of breast carcinoma. The purpose of this study was to investigate the significance of apoptosis-related genes bcl-2 and Bax and their correlation with expression of p53, tumor proliferation defined by MIB-1 expression and estrogen receptor status. Immunohistochemistry was performed to determine Bcl-2, Bax, p53, estrogen receptor (ER) and MIB-1 expression in paraffin-embedded tissues of 177 invasive breast cancers. Expression of the anti-apoptotic protein Bcl-2 was not correlated with the pro-apoptotic Bax. Bcl-2 immunostaining displayed a negative correlation with increasing histologic grade, p53 and MIB-1 (P < 0.0001, P < 0.05 and P < 0.0001, respectively) and a positive correlation with rising ER immunostaining (r = 0.305, P < 0.0001). Conversely, expression of the apoptosis-promoting protein Bax did not correlate with increasing histologic grade, p53, MIB-1 or ER status. Neither Bcl-2 expression nor Bax expression correlated with age, menopausal status, tumor size, histologic type or axillary lymph node status. These results imply that Bcl-2 is associated with good prognostic markers and the regulation of Bax is complex and does not necessarily correlate with mutant p53 status in breast cancers.

[Effective alendronate therapy against a bone metastasis occurring during docetaxel therapy for breast cancer--a case report].

A 65-year-old woman underwent radical operation for breast cancer in December, 1992. Between September, 1994 and January, 1997, she developed local recurrences four times as well as a supraclavicular lymph node recurrence. Each recurrence was treated with surgery and various types of chemoendocrine therapy, including anthracycline-containing chemotherapy. In April, 1997, she had developed a liver metastasis, which showed a partial response to docetaxel therapy. However, she developed a bone metastasis in January, 1998 (9 months after the initiation of docetaxel therapy). In addition to the docetaxel therapy, she was treated with a potent bisphosphonate, alendronate, 10 mg of which was infused every two weeks. Eight alendronate infusions resulted in a marked improvement in the bone metastasis, and the liver metastasis has been in regression for 13 months in response to the docetaxel therapy. In conclusion, alendronate is a promising agent against bone metastases which occur during docetaxel therapy for breast cancer.