須藤 保

OBJECTIVE: Uterine carcinosarcoma (UCS) is a rare and aggressive gynecological cancer with high recurrence rates and is associated with a poor prognosis. It is also characterized by a high frequency of copy number alterations (CNAs). This study aimed to determine which gene CNA contributes to progression-free survival (PFS) in patients with UCS to identify potential prognostic biomarkers and therapeutic targets. METHODS: DNA was extracted from formalin-fixed paraffin-embedded tissues of surgical specimens from 24 patients with UCS who were treated at Fujita Health University. Using the PleSSision-Rapid test, the mutation information of 145 cancer genes was analyzed. Oncoplot analysis was used to visualize gene mutation profiles. χ2 test, Kaplan-Meier analysis, and log-rank test were used for statistical analyses. RESULTS: The most frequently observed gene mutation was TP53 in the 24 UCS cases studied, while genes associated with the PI3K/AKT/mTOR signaling pathway, including PIK3CA, PTEN, PIK3R1, and PIK3R2 were commonly detected. In the χ2 test analysis, TP53 loss (p=0.029), PIK3CA amplification (p=0.034), and TSC2 loss (p=0.034) were significantly associated with recurrence. Kaplan-Meier survival analysis demonstrated a significant association between PIK3CA amplification and TSC2 loss with PFS, as determined by the log-rank test (p<0.05). CONCLUSION: In patients with UCS, TSC2 loss is linked to poorer PFS, highlighting its utility as a prognostic marker. The association between TSC2 loss and increased recurrence risk highlights the potential therapeutic advantage of targeting the mTOR pathway in TSC2-deficient tumors.

Platinum-resistant ovarian cancer (PROC) is a clinically severe unresolved issue, and it remains unclearly defined by molecular biology. Extracellular vesicles (EVs) play an essential role in cell-to-cell communication in the tumor microenvironment. This study aimed to investigate the molecular mechanisms of PROC, focusing on the unique ascites environment of ovarian cancer. Multi-transcriptome analyses using clinical samples revealed that PROC exhibited an activated Janus kinase (JAK)/signal transducer and activator of transcription pathway with high JAK1 expression in cancer cells. Immunohistochemistry for patient tissues confirmed the negative association between JAK1 expression and platinum response. JAK inhibitors were effective in PROC cell lines and cell- and patient-derived xenograft models, as well as synergistic with platinum. Furthermore, small RNA sequencing indicated that activated peritoneal mesothelial cell-derived EVs enriched in miR135a-5p increased JAK expression and platinum resistance in cancer cells. Collectively, EVs in ascites regulated platinum sensitivity in ovarian cancer cells, and JAK targeting therapeutic strategy overcomes PROC.

Epithelioid sarcoma (ES) is a very rare malignant tumor with few effective treatments other than surgical resection. In this study, the efficacy of BNCT for ES was examined using human ES-derived VA-ES-BJ cell-bearing nude mice. Only tumors in the BNCT group injected with p-borono-L-phenylalanine-fructose complex and irradiated with neutrons were destroyed. This study suggests the potential of BNCT as a new option for the treatment of human ES.

BACKGROUND: Cancer gene panel testing (CGP) helps comprehensively analyze a large number of genes, extracting genetic information from the genome profile to aid treatment plans and drug therapy. Advances in drug therapy and surgical treatment for intrahepatic cholangiocarcinoma (ICC) have improved patient outcomes; however, it remains a typical intractable cancer with a poor prognosis. ICC is one of the key tumors for which effective treatment may be identified through CGP testing. This study aimed to identify ICC harboring actionable genetic variants using contrast-enhanced ultrasonography (CE-US). METHODS: We enrolled 26 ICC patients who underwent CE-US before chemotherapy or surgery. Three ultrasound specialists reviewed the images by consensus and assessed the imaging features, including vascularity. Pathological data were reviewed after diagnosis using CE-US. We retrospectively analyzed distinctive CE-US findings in patients with ICC with actionable genetic variants. RESULTS: Twelve ICC patients had actionable gene variants, including four FGFR2 fusions, one FGFR2 rearrangement, six IDH1 mutations, and one BRAF V600E mutation. Univariate analysis showed significant differences in bile duct invasion (p = 0.0217) and blood vessel penetration within the tumor (p = 0.0012). Multivariable logistic regression identified blood vessel penetration within the tumor (OR = 18.275; 95% CI: 1.331-250.925; p = 0.0297) as independently associated with actionable gene variants. CONCLUSION: Patients with ICC and blood vessel penetration on CE-US should be considered for CGP testing.

Myxofibrosarcoma, a rare malignant tumor, predominantly affects the extremities of the elderly. Because of its invasive nature amputation is sometimes required, resulting in serious deterioration of quality of life. Therefore, cell lines established from amputated surgical specimens of myxofibrosarcoma in the upper limbs of elderly patients were used to create a myxofibrosarcoma-bearing animal model and to investigate the therapeutic effect of BNCT thereon. The results demonstrated selective destruction of tumor cells, suggesting the anti-tumor efficacy of BNCT on myxofibrosarcoma.