Thermotherapy using magnetic cationic liposomes powerfully suppresses prostate cancer bone metastasis in a novel rat model.

BACKGROUND: Bone metastasis is a serious problem for individuals with prostate cancer, and the effects of the anticancer drug docetaxel (DTX) are insufficient. We therefore examined the therapeutic potential of magnetic cationic liposomes (MCL) in a novel rat model that allows the evaluation of tumor immunity. The effects of MCL thermotherapy were compared with those of DTX as a conventional therapy for the treatment of bone metastatic prostate cancer. METHODS: Prostate tumor tissues were transplanted into the femurs of model rats divided into four groups: control, MCL, DTX, and MCL + DTX. Tumors were injected with MCL, and alternating magnetic field (AMF) irradiation was performed three times a week. Tumor proliferation and bone destruction were evaluated by proliferating cell nuclear antigen positivity, computed tomography, and CD68-positive cell number, while tumor immunity was evaluated by heat shock protein (HSP) 70 expression and CD8-positive lymphocyte number. RESULTS: We successfully established a novel femur metastasis model of prostate cancer, and demonstrated that tumor proliferation and bone destruction in the MCL and MCL + DTX groups were significantly suppressed compared with control and DTX groups. MCL thermotherapy concurrently induced necrosis and apoptosis. The expression of HSP70 in the MCL and MCL + DTX groups was also significantly increased, and tumor immunity was enhanced through the induction of CD8-positive lymphocytes. CONCLUSION: MCL thermotherapy was clearly more effective than DTX in treating bone metastatic prostate cancer. A combination of MCL thermotherapy and DTX therefore deserves consideration as a novel treatment for this disease.

Single nucleotide polymorphisms of mucosa-associated lymphoid tissue 1 in oral carcinoma cells and gingival fibroblasts.

Oral carcinoma patients with inactivation of mucosa-associated lymphoid tissue 1 (MALT1) expression worsen their prognoses. Although the genetic mutation could be responsible for the inactivation, no information is available at present. In the present study, genomic DNA of oral carcinoma cells (HOC313, TSU, HSC2, HSC3, KOSC2, KOSC3, SCCKN, OSC19, Ca9.22, and Ho1u1 cells) and normal gingival fibroblasts (GF12 cells) derived from a Japanese population were amplified by polymerase chain reaction using primer sets spanning MALT1 exons, and nucleotide substitutions were analyzed by the single strand conformation polymorphism analysis. The substitutions were commonly observed in all cells, which express MALT1 at various levels. The substitutions at exons 1 and 9 were located at the 5' untranslated region and replaced (336)Asp to Asn, respectively, and others were positioned at the introns. Among the intronic substitutions, four were matched with the single nucleotide polymorphisms (SNPs) registered at the database. Since all cells were derived from a Japanese population, all substitutions detected are the SNPs. Absence of the carcinoma cell-specific mutation suggests that the inactivation of MALT1 expression but not the mutation promotes oral carcinoma progression.

A clinical trial of a unidirectional porous tricalcium phosphate filling for defects after resection of benign bone lesions: a prospective multicenter study.

Affinos (Kuraray, Japan) is a ß-tricalcium phosphate bone substitute with a unidirectional porous structure. This study aimed to investigate its efficacy on the healing process after filling for bone defects. Fifty-six patients who met the inclusion criteria were divided into cohort 1 (n = 30), including bones other than phalanges and metacarpal/tarsal bones, and cohort 2 (n = 26), including phalanges and metacarpal/tarsal bones. Semi-quantified scores for material resorption and trabeculation through the defect were evaluated with radiographs after surgery. In some patients, levels of bone metabolic markers were assessed. The values of resorption and trabeculation increased steadily with time, and trabeculation progressed compared with resorption in both cohorts. In cohort 1, multiple regression analyses showed that the diaphyseal lesion, smaller defect volume, and increased resorption values at 3 months were associated with increased values of resorption 12 months after surgery (R2 = 0.66, p < 0.001). The trabeculation values at 2 months were positively related to the trabeculation values 12 months after surgery (R2 = 0.35, p = 0.002). In cohort 2, the increased resorption values at 2 months and smaller defect volume significantly correlated with the increased resorption values 12 months after surgery (R2 = 0.58, p < 0.001). The ratio from the baseline of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen at 3 months was negatively associated with the trabeculation values 12 months after surgery (R = - 0.791, p = 0.004). Evaluation of radiographic images and bone metabolic markers in the early postoperative period may predict the healing status at 12 months postoperatively in the defects followed by Affinos filling.