High concentration of beta-defensin-2 in oral squamous cell carcinoma

We have previously reported the presence of human beta-defensin-2 (HBD-2), a peptide with antimicrobial and cytotoxic properties, in oral squamous cell carcinomas. The aim of the present study was to measure the concentration of HBD-2 in abnormal tissues such as oral squamous cell carcinomas. HBD-2 was extracted from tissue samples in the presence of retinoic acid and subjected to reversed-phase HPLC. The fraction representing peak 17 (P17) was obtained by elution using a linear gradient of acetonitrile. Amino acid sequencing and homology studies were subsequently performed, and the molecular weight of P17 was calculated to be 432702 daltons. This molecular weight was consistent with HBD-2. The concentration of HBD-2 in the oral squamous cell carcinoma samples was 3.85+/-1.87 microg/mg which was much higher than in normal oral epithelium (0.04+/-0.02 microg/mg).     

Hepatocyte nuclear factor (HNF)-4alpha induces expression of endothelial Fas ligand (FasL) to prevent cancer cell transmigration: a novel defense mechanism of endothelium against cancer metastasis.

Endothelial Fas ligand (FasL) contributes to the "immune privilege" of tissues such as testis and eye, in which apoptosis is induced in infiltrating Fas-positive activated T cells and results in the inhibition of leukocyte extravasation. In this study, we examined the role of endothelial FasL in controlling cancer cell transmigration using rat lung endothelial (RLE) cell line bearing a doxycycline-inducible hepatocyte nuclear factor (HNF)-4alpha expression system. We showed that a detectable level of FasL was expressed in RLE cells and that this expression was markedly up-regulated and well correlated to the degree of HNF-4alpha expression in a time-dependent manner. When various cancer cells were overlaid on an RLE monolayer sheet, we examined the ability of endothelial FasL to induce massive apoptosis in Fas-expressing cancer cells and found a causal link to inhibition of the transmigration. Finally, we showed that FasL was expressed in capillaries of the rat brain by immunohistochemical staining, suggesting that FasL serves its functions not only in vitro, but also in vivo. These results raise the possibility that HNF-4alpha is involved in regulating cancer cell transmigration by modulating the Fas-FasL system.     

Genetic alterations in adenoma-carcinoma sequencing of intraductal papillary-mucinous neoplasm of the pancreas

We investigated the adenoma-carcinoma sequence in intraductal papillary-mucinous neoplasm from the aspect of genetic changes. The formalin-fixed paraffin-embedded tumors and surrounding normal pancreatic tissues from patients with 16 intraductal papillary-mucinous adenoma of the pancreas (IPMA) and 10 intraductal papillary-mucinous carcinoma of the pancreas (IPMC) were provided for DNA extraction after microdissection. SSCP-DNA sequencing analysis demonstrated K-ras mutations at codon 12 in 75% of IPMA and 70% of IPMC, while those at codon 13 were observed neither in IPMA nor IPMC. There were no characteristic K-ras mutation types in IPMA and IPMC and no significant differences in incidence of K-ras mutations between the two categories. The frequencies of p53 mutations analyzed by SSCP-DNA sequencing were not high in IPMA (18.8%) and IPMC (30%), showing no significant difference between them. LOHs of APC in IPMA and IPMC were infrequent (6.3 and 20%, respectively) and showed no significant difference in incidence between the two categories. The LOH frequencies of DCC in IPMA and IPMC were 31.3 and 40%, respectively, and were not statistically different from each other. Taken together, genetic changes such as K-ras, p53, APC and DCC mutations may not be associated with adenoma-carcinoma sequence in intraductal papillary-mucinous neoplasm of pancreas.     

Prognostic factors in elderly patients with acute myelogenous leukemia: a single center study in Japan

We retrospectively analyzed data of 47 patients aged 60 years or older, hospitalized in our institution with the diagnosis of acute myelogenous leukemia (AML), and searched for prognostic factors. Induction with anthracyclines significantly correlated with better complete remission (CR) rate (P = 0.0016) and overall survival (OS) (P < 0.001). Another factor significantly affecting CR rate was higher age (> 70 years) (P = 0.042). Therapy-non-related factors predictive for shorter OS in univariate analyses were age older than 70 years (P = 0.003), percentage of blasts in bone marrow more than 80% (P = 0.048), serum lactate dehydrogenase level higher than 250 U l(-1) (P = 0.032). In stepwise cox proportional hazard regression model, all the four factors predictive for poor OS remained to be independently and significantly prognostic for shorter OS. Only two patients receiving anthracyclines died within 30 days and the frequency was not different from that in patients not receiving anthracyclines. The use of anthracyclines as induction therapy is recommended even in the elderly patients.     

Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type of the liver in a patient with hepatitis C virus infection

We report a case of primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type of the liver presenting as a solitary mass in a patient with hepatitis C virus infection. A 73-year-old male was referred to our hospital because of a solitary mass in the liver, which was identified by ultrasonography during a routine follow-up study for his hepatitis C virus carrier status. A fine-needle biopsy was performed and the mass was diagnosed as non-Hodgkin's lymphoma. A detailed investigation showed no evidence of lymphoma in other sites. Left lateral segmentectomy was performed. Histologic examination showed diffuse, monotonous infiltration of centrocyte-like cells that are CD 19(+), CD 20(+), sIgM-lambda(+), CD 3(-), CD 5(-), CD 10(-). The patient received no adjuvant chemotherapy and is alive and disease free 34 months after surgery.     

Characterization of rat monoclonal antibodies against human beta-defensin-2

Defensins are a family of cationic antimicrobial peptides that participate in host defense. Human beta-defensin (hBD)-2 has a potent bactericidal activity against a wide spectrum of microorganisms. Because human gingival epithelium is constantly exposed to a variety of microbial challenges, it is considered that hBD-2 has an important role in the protective mechanisms against oral bacterial infection. However, little is known about the production of hBD-2 in tissues of the oral cavity. Six rat monoclonal antibodies (MAbs) raised against chemically synthesized hBD-2 have been characterized. Rat MAbs were specific for the conformational epitopes on hBD-2, but not to hBD-1. To identify the epitope on hBD-2, a series of six overlapping peptides covering the hBD-2 whole sequence were synthesized and the immunoreactivities of six MAbs were examined. The FCPRRYK domain in hBD-2 was recognized by all six MAbs and suggested to be an epitope region. By immunocytochemistry, hBD-2 was localized focally in the epidermis of the human gingival tissue using the MAbs. The MAbs specifically recognized against hBD-2 will be a useful tool to study the functional role of antimicrobial agents and an important asset in the imaging of oral infection processes.     

Extracellular Bad fused to toxin transport domains induces apoptosis

Bad, a proapoptotic member of the Bcl-2 family, is inactivated by phosphorylation, and this loss of activity may contribute to the malignancy of certain types of tumors such as glioblastoma and prostate cancer. To determine whether extracellular Bad can be delivered into cells via cell surface receptor binding and induce apoptosis, we genetically fused the mouse Bad gene to the gene for the translocation and receptor-binding domains of diphtheria toxin (DTTR). The purified Bad (wild-type)-DTTR protein showed cytotoxicity to human glioma cells in a dose-dependent manner. Bad phosphorylation sites at codons 112 and 136 were mutated from serine to alanine to prevent Bad inactivation by kinases and to increase the toxicity of Bad. The Bad (S112A S136A)-DTTR protein was at least 5 times more toxic than Bad (wild-type)-DTTR with an IC(50) of 5 x 10(-8) M. The Bad (S112A S136A)-DTTR protein altered the subcellular distribution of Bcl-X(L), indicating that it enters the cell cytoplasm and binds Bcl-X(L). Bad (S112D S136A)-DTTR, mutated to mimic phosphorylation of Bad, showed lower toxicity than either Bad (wild-type)-DTTR or Bad (S112A S136A)-DTTR, additionally indicating that Bad-DTTR must bind Bcl-X(L) to stimulate apoptosis. We conclude that extracellular Bad can be delivered into cells via the transport domain of a bacterial toxin and may be used to induce apoptosis.     

Three-dimensional intrafractional movement of prostate measured during real-time tumor-tracking radiotherapy in supine and prone treatment positions

To quantify three-dimensional (3D) movement of the prostate gland with the patient in the supine and prone positions and to analyze the movement frequency for each treatment position.

The real-time tumor-tracking radiotherapy (RTRT) system was developed to identify the 3D position of a 2-mm gold marker implanted in the prostate 30 times/s using two sets of fluoroscopic images. The linear accelerator was triggered to irradiate the tumor only when the gold marker was located within the region of the planned coordinates relative to the isocenter. Ten patients with prostate cancer treated with RTRT were the subjects of this study. The coordinates of the gold marker were recorded every 0.033 s during RTRT in the supine treatment position for 2 min. The patient was then moved to the prone position, and the marker was tracked for 2 min to acquire data regarding movement in this position. Measurements were taken 5 times for each patient (once a week); a total of 50 sets for the 10 patients was analyzed. The raw data from the RTRT system were filtered to reduce system noise, and the amplitude of movement was then calculated. The discrete Fourier transform of the unfiltered data was performed for the frequency analysis of prostate movement.

No apparent difference in movement was found among individuals. The amplitude of 3D movement was 0.1–2.7 mm in the supine and 0.4–24 mm in the prone positions. The amplitude in the supine position was statistically smaller in all directions than that in the prone position (p < 0.0001). The amplitude in the craniocaudal and AP directions was larger than in the left-right direction in the prone position (p < 0.0001). No characteristic movement frequency was detected in the supine position. The respiratory frequency was detected for all patients regarding movement in the craniocaudal and AP directions in the prone position. The results of the frequency analysis suggest that prostate movement is affected by the respiratory cycle and is influenced by bowel movement in the prone position.

The results of this study have confirmed that internal organ motion is less frequent in the supine position than in the prone position in the treatment of prostate cancer. RTRT would be useful in reducing uncertainty due to the effects of the respiratory cycle, especially in the prone position.     

Combination chemotherapy with carboplatin and etoposide for elderly patients aged 76 years or older with small cell lung cancer

Eighteen elderly patients aged 76 years or older with small cell lung cancer were treated with carboplatin (AUC = 4 mg/ml.min, i.v. day 1) and etoposide (70 mg/m2 i.v. day 1-3) and 17 patients were evaluable. The median age of the study population was 77 years (range: 76-81). Eight patients had limited disease (LD) and nine did extensive disease (ED). The overall response rate was 88% for LD patients and 67% for ED patients. Median survival time was 219 days for LD patients and 158 days for ED patients. Grade 3 and 4 leukopenia, neutropenia, thrombocytopenia and anemia occurred in 41%, 76%, 24% and 6% of patients, respectively. There was one treatment-related death due to pneumonitis.