Jun Fujimori

Antitumor effects of telomerase inhibitor TMPyP4 in osteosarcoma cell lines

Telomere studies in carcinomas have been extensively reported for prognostic utility and effective methods for targeting telomerase therapy has been described, but efficacy of telomerase inhibitor remained unknown in sarcoma cells. In this study, we investigated the effects of telomerase inhibitor cationic porphyrin TMPyP4 on telomerase activity, telomere length, cell growth, and apoptosis in osteosarcoma cell lines. TMPyP4 significantly inhibited telomerase activity in telomerase positive HOS and Saos‐2, but not in MG‐63. TMPyP4 significantly induced telomere shortening, and inhibition of the cell growth in HOS and Saos‐2 with over 17% apoptosis rates. In terms of MG‐63, TMPyP4 did not induce inhibition of both telomerase activity and cell growth, although it induced significant telomere shortening. Telomere length after treatment was 5.60 kb in HOS, 4.00 kb in Saos‐2, and 9.89 kb in MG‐63. These results may suggest that both telomerase activity loss and sufficient telomere shortening are necessary to inhibit cell growth in telomerase positive osteosarcoma cells. TMPyP4 did not induced telomere shortening but significantly inhibited the growth with 22.6% apoptosis rate in telomerase negative with extremely longer telomere‐U2OS, may indicating the antitumor effect of TMPyP4 may be related to DNA damage including telomere dysfunction through G‐quadruplex stabilization, independent on telomere length.

Oncolytic vesicular stomatitis virus administered by isolated limb perfusion suppresses osteosarcoma growth

A significant limitation to oncolytic virotherapy in vivo is the lack of a clinically relevant means of delivering the virus. We evaluated the oncolytic activity of vesicular stomatitis virus (VSV) in human osteosarcoma cells and explored isolated limb perfusion (ILP) as a novel oncolytic virus delivery system to extremity sarcoma in immune‐competent rats. Human and rat osteosarcoma cells transduced with rVSV‐lacZ uniformly expressed β‐gal. VSV was fully capable of replicating its RNA genome in all osteosarcoma cell lines, and efficiently killed them in time‐ and dose‐dependent manners, whereas normal bone marrow stromal cells were refractory to the virus. VSV delivered by ILP inhibited growth of osteosarcoma xenografts more potently than that injected intravenously and intratumorally in the hind limb of immune‐competent rats. Histopathological sections of tumor lesions treated by ILP‐delivered VSV showed positive for VSV‐G protein. There were no VSV‐G expressions in perfused leg muscle, nonperfused leg muscle, brain, lung, and liver in VSV‐treated rats. Our findings show efficient VSV gene expression and replication in osteosarcoma cells, suggesting that osteosarcoma may be a promising target for oncolytic virotherapy with VSV. Furthermore, we firstly showed that ILP of VSV against extremity sarcoma caused antitumor activity.

Interferon-α/β Receptor as a Prognostic Marker in Osteosarcoma

BACKGROUND A large-scale randomized trial of adjuvant interferon-α therapy for patients with osteosarcoma has been initiated as a joint protocol by the European and American Osteosarcoma Study Group. Because the expression of functional interferon-α/β receptor is necessary for interferon-α agents to interact with osteosarcoma cells, we examined the expression of interferon-α/β receptor in a series of osteosarcoma specimens. METHODS Forty patients with high-grade resectable osteosarcoma, from whom surgical specimens had been obtained at the time of biopsy, were included in this retrospective study. Biopsy specimens were immunohistochemically stained with anti-interferon-α/β receptor antibodies. Survival was estimated with the Kaplan-Meier method. The Cox proportional hazards model was used for multivariate analysis to determine the independent prognostic factors. Furthermore, we used Holm and Benjamini-Hochberg procedures to adjust for multiple comparisons in setting the level of significance. The median follow-up period was five years and two months (range, four to 195 months). RESULTS The expression of interferon-α/β receptor was positive in eighteen (45%) of the forty patients with high-grade osteosarcoma. American Joint Committee on Cancer surgical stage IIA, a good histologic response to chemotherapy, and expression of interferon-α/β receptor correlated significantly with better disease-free survival (p < 0.05). Multivariate analysis showed that interferon-α/β receptor expression alone retained its power to predict an improved prognosis (p = 0.042). There were no significant variables after corrections for multiple comparisons. CONCLUSIONS Interferon-α/β receptor may be a useful marker for assessing tumor prognosis in patients with osteosarcoma and may play an important role in tumor progression. These findings are encouraging and support the ongoing clinical trials of adjuvant interferon-α therapy by the multinational Osteosarcoma Study Group. Our pilot study was based on a small sample size, and larger trials are needed to confirm this finding. LEVEL OF EVIDENCE Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Prognostic value of PAX3/7–FOXO1 fusion status in alveolar rhabdomyosarcoma: Systematic review and meta-analysis

PURPOSE The objective of this systematic review is to provide an unprecedented summary of the prognostic impact of PAX3/7-FOXO1 fusion status in alveolar rhabdomyosarcoma. METHODS Studies evaluating PAX3/7-FOXO1 fusion gene or its variants as a prognostic marker were systematically searched and comparative meta-analysis of overall survival was carried out. RESULTS A total of 7 studies comprising 993 patients with rhabdomyosarcoma were included. Three eligible studies showed no significant difference of survival between fusion positive and negative alveolar rhabdomyosarcoma. Four eligible studies showed that PAX3-FOXO1 fusion variant may indicate a lower survival probability than PAX7-FOXO1, although the effect did not reach a level of statistical significance (pooled hazard ratios, 1.66; 95% CI, 0.95-2.89; p=0.07). CONCLUSIONS There was no significant difference in the overall survival between patients with the positive and negative fusion gene, but there were indications of PAX3-FOXO1 being an unfavorable prognostic factor.

Minodronate for the treatment of osteoporosis.

Minodronate, a new nitrogen-containing bisphosphonate, was developed in Japan. It was the first drug to demonstrate significant prevention of vertebral fractures in Japanese patients with osteoporosis in a phase III doubleblind comparative study. As a result of positive data from clinical trials in Japan minodronate was granted a Japanese marketing approval for the treatment of osteoporosis on January 21, 2009. In vitro studies demonstrated that minodronate is one of the most potent inhibitors of bone resorption among currently available bisphosphonates. Preclinical studies demonstrated the inhibitory effect of minodronate on the decrease in the bone mineral density (BMD) in ovariectomized rats, dogs and monkeys. Daily oral minodronate was safe, well tolerated and effective in reducing vertebral fracture risk in postmenopausal women with established osteoporosis. The effects on lumbar and hip BMD and the safety profile of minodronate are comparable to those of alendronate. These data suggest that minodronate is a promising new potent bisphosphonate for the treatment of osteoporosis.

Quantitative 201thallium scintigraphy for prediction of histological response to neoadjuvant chemotherapy in osteosarcoma; systematic review and meta-analysis

PURPOSE The histological assessment of tumor necrosis of the excised lesion after neoadjuvant chemotherapy is the most important prognostic factor for patients with osteosarcoma, but more early prognostic factors are needed for the adjustment of adjuvant treatment regimen. The objective of this systematic review is to provide an up-to-date and unprecedented summary of the value of (201)thallium ((201)Tl) scintigraphy for the preoperative evaluation of the chemotherapy response of osteosarcoma. METHODS Studies evaluating (201)Tl scintigraphy for the preoperative evaluation of the chemotherapy response of osteosarcoma were systematically searched for in MEDLINE, EMBASE, and Web of Science. Pooled sensitivity and specificity for each study were calculated into 2 × 2 contingency tables. The DerSimonian-Laird random-effects method was used for determining the pooled diagnostic odds ratio and the area under curve (AUC) of the summary receiver operating characteristic (SROC) curve. RESULTS A total of six studies with 139 patients who fulfilled all of the inclusion criteria were considered for the meta-analysis. The pooled sensitivity and specificity were 0.93 (95% CI, 0.83-0.98) and 0.63 (95% CI, 0.52-0.74), respectively. A significant difference was found between the good and poor responders in the diagnostic odds ratio. The SROC curve showed that the AUC was 0.840, indicating excellent diagnostic accuracy. There was no statistically significant heterogeneity among the six studies. CONCLUSIONS The alteration ratio derived from (201)Tl scintigraphy was useful for evaluating the histological response of patients to neoadjuvant chemotherapy in osteosarcoma.

Extraosseous Extension Caused by Epidural Hematoma in Gaucher Disease Mimicking Malignant Bone Tumor

Gaucher disease is an inherited autosomal-recessive disorder caused by the defective hydrolysis of glucocerebroside. The resultant hepatosplenomegaly, hematological changes, and orthopedic complications are the predominant symptoms. However, extraosseous manifestation of Gaucher disease, mimicking malignant bone tumor, is supposed to be rare. No reports of extraosseous manifestation of Gaucher disease caused by epidural hematoma were identified in the English literature. A 64-year-old man visited a nearby clinic for low back pain and was referred to our tumor clinic on suspicion of malignant bone tumor on sacral MRI. MRI revealed a demarcated solid lesion extending into the surrounding soft tissues on both sides of the sacral roots. During preoperative examination, he suffered from pathologic fracture in right mid-femur. We performed internal fixation with intramedullary nailing, simultaneously harvesting tissue specimens. Histopathological analysis showed aggregates of Gaucher cells in the right femur and hematoma in the sacrum. Epidural hematoma in Gaucher disease, usually attributed to thrombocytopenia, is a rare manifestation of skeletal complication, mimicking malignant processes.