Shin-ichi Tsuchiya

Increased nuclear localization of transcription factor Y-box binding protein 1 accompanied by up-regulation of P-glycoprotein in breast cancer pretreated with paclitaxel.

Purpose: The Y-box binding protein 1 (YB-1) regulates expression of P-glycoprotein encoded by the MDR1 gene. There have been no previous studies regarding the involvement of YB-1 in the development of resistance to paclitaxel. The present study was done to examine how paclitaxel affects the localization and expression of YB-1 in breast cancer. Experimental Design: We evaluated the expression and localization of YB-1 and P-glycoprotein in breast cancer tissues obtained from 27 patients before and after treatment with paclitaxel. The effect of paclitaxel on localization of cellular YB-1 was examined by using GFP-YB-1. Interaction of YB-1 with the Y-box motif of the MDR1 promoters was studied by electrophoretic mobility shift assay. The effects of paclitaxel on MDR1 promoter activity were examined by luciferase assay. Results: Of 27 breast cancer tissues treated with paclitaxel, nine (33%) showed translocation of YB-1 from the cytoplasm to the nucleus together with increased expression of P-glycoprotein during the course of treatment. Twelve breast cancer tissues (44%) showed neither translocation of YB-1 nor increased expression of P-glycoprotein. Nuclear translocation of YB-1 was correlated significantly with increased expression of P-glycoprotein (P = 0.0037). Confocal analysis indicated that paclitaxel induced nuclear translocation of green fluorescent fused YB-1 in MCF7 cells. Furthermore, binding of YB-1 to the Y-box of MDR1 promoter was increased in response to treatment with paclitaxel. In addition, MDR1 promoter activity was significantly up-regulated by paclitaxel in MCF7 cells (P < 0.001). Conclusions: The results of the present study suggested that YB-1 may be involved in the development of resistance to paclitaxel in breast cancer.

Involvement of vascular endothelial growth factor and urokinase-type plasminogen activator receptor in microvessel invasion in human colorectal cancers.

To evaluate the association among known angiogenic growth factors or factors related to the plasminogen activation system and clinicopathological factors in patients with colorectal cancer, we examined the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor‐α (TGF‐α), urokinase‐type plasminogen activator (u‐PA), u‐PA receptor (u‐PA‐R) and plasminogen activator inhibitor‐1 (PAI‐1) in clinical specimens of colorectal cancers by Northern blot analysis. In comparison with the expression of these angiogenesis‐related genes in 7 paired samples of colorectal cancers and the adjacent normal mucosa, VEGF mRNA level was significantly higher in the cancer tissues than in the adjacent normal mucosa (p < 0.05). We analyzed expression of these genes in 44 cases of primary colorectal cancers. Among the 3 angiogenic growth factors we examined, VEGF mRNA expression was significantly higher in the cancer tissues with blood vessel invasion or with lymphatic vessel invasion than in those without, respectively (p < 0.05). On the other hand, u‐PA‐R mRNA expression was significantly higher in the cancers with blood vessel invasion than in those without (p < 0.05). In addition, there was a correlation between the expression levels of VEGF and u‐PA‐R mRNA in the cancer tissues we have examined. Using immunohistochemistry, strong staining of VEGF or u‐PA‐R was observed in the cancer cells invading the microvessels. Our findings suggest that malignant transformation might accompany the upregulation of VEGF expression in colorectal cancers and that VEGF and u‐PA‐R might contribute cooperatively to increase angiogenesis around the tumor as well as the metastasis via microvessels. Int. J. Cancer (Pred. Oncol.) 79:179–186, 1998.© 1998 Wiley‐Liss, Inc.

Pseudosarcoma of the esophagus

A 64-year-old man with pseudosarcoma of the esophagus is described.Morphologic examinations of this rare tumor were made, and the origin of the sarcoma-like cells of the tumor is discussed. The findings for the sarcoma-like cells of the tumor support the idea that the sarcoma-like elements arose through transformation of epithelial cells. The patient was unable to undergo surgical treatment and died of a generalized fungal infection.

Mutation of the class I β-tubulin gene does not predict response to paclitaxel for breast cancer

Mutation of the class I beta-tubulin gene has been reported to be one of the mechanisms that cause resistance to paclitaxel. To assess the relationship between paclitaxel-resistance and class I beta-tubulin gene mutation in breast cancer, Japanese patients with breast cancer were screened for the class I beta-tubulin gene mutation. Total RNA was isolated from 82 breast cancer specimens and the corresponding normal tissues. Twenty-four of the 82 patients were treated with paclitaxel preoperatively and 12 of them did not respond to the treatment. Of the 82 breast cancer patients, 15 (18.3%) had silent polymorphism in exon 4, Leu217Leu (CTG/CTA). However, no mutations showing amino acid substitution of the beta-tubulin gene were detected in any of the patients, including 12 patients who did not respond to paclitaxel. Class I beta-tubulin gene mutation with amino acid substitution was not detected in 82 breast cancer specimens. Our results suggest that mutation of the class I beta-tubulin gene is unlikely to play an important role in the mechanism of resistance to paclitaxel in breast cancer.

DYSPLASIA AND RESERVE CELL HYPERPLASIA-LIKE CHANGE IN HUMAN ESOPHAGUS

The esophagus was totally examined in 264 autopsied cases and 61 operated cases, for a total of 325 cases, to clarify the histogenesis of squamous cell carcinoma of the esophagus. Epithelial dysplasia of the mucosa was present in 27% and subclinical carcinoma was found in 2.4%. Hyperplasia of the duct of the esophageal gland proper was present in 34% and dysplasia of the ductal epithelium in 3%. Reserve cell hyperplasia‐like change of the islet of the ectopic gastric mucosa was found in 4% and reserve cell hyper‐plasia‐like change of the esophagogastric junction zone in 13%. Of the seven cases of microcarcinoma, two showed dysplasia and gradual transition and one presented dysplasia and abrupt transition. Another two were considered to have originated in the ductal epithelium. These findings suggested that they could all be the sites of origin of cancer development.

The miR-221/222 cluster, miR-10b and miR-92a are highly upregulated in metastatic minimally invasive follicular thyroid carcinoma

Minimally invasive follicular thyroid carcinoma (MI-FTC) is characterized by limited capsular and/or vascular invasion with good long-term outcomes. However, some cases of MI-FTC show a poor prognosis because of severe distant metastasis (i.e., metastatic MI-FTC). Nonetheless, no method has been established for predicting the prognosis of MI-FTC. This study was conducted to identify novel prognostic factors for metastatic MI-FTC by the use of microRNA (miRNA). Thirty-four patients with MI-FTC were categorized into two groups: the metastatic group, M(+) (n=12) and the non-metastatic group, M(−) (n=22). In the M(+) group, distant metastasis was recognized after the initial operation established the diagnosis of MI-FTC. In the M(−) group, no distant metastasis was recognized postoperatively for ≥10 years. Using laser micro-dissection followed by quantitative real-time PCR and PCR arrays, we performed a comprehensive expression profiling of 667 miRNAs in formalin-fixed, paraffin-embedded samples from the initial MI-FTC operation. Furthermore, we assessed the potential use of miRNAs as novel biomarkers for the metastatic potential of MI-FTC by logistic regression analysis. Comprehensive quantitative analysis of miRNA expression in MI-FTC samples revealed that the miR-221/222 cluster (i.e., miR-221, miR-222 and miR-222*), miR-10b and miR-92a were significantly upregulated in the M(+) group compared with the M(−) group. Interestingly, the expression levels of these miRNAs were also shown to be upregulated in widely invasive FTC (WI-FTC; n=13) that has distant metastasis and worse prognosis, indicating a close similarity in the miRNA expression between metastatic MI-FTC and WI-FTC. Logistic regression analysis revealed that miR-10b made a significant contribution to prognosis (OR 19.759, 95% CI 1.433–272.355, p= 0.026). Our findings suggest that miR-10b is a potential prognostic factor for evaluating the metastatic potential of MI-FTC at an initial operation stage.

Activity of EGFR-tyrosine kinase and ALK inhibitors for EML4-ALK-rearranged non-small-cell lung cancer harbored coexisting EGFR mutation.

BackgroundThe EML4–ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) fusion oncogene represents a novel molecular target in a small subset of non–small–cell lung cancers (NSCLCs). The EML4–ALK fusion gene occurs generally in NSCLC without mutations in epidermal growth factor receptor (EGFR) and KRAS.Case presentationWe report that a case of EML4–ALK-positive NSCLC with EGFR mutation had a response of stable disease to both an EGFR tyrosine kinase inhibitor (EGFR-TKI) and ALK inhibitor.ConclusionsWe described the first clinical report of a patient with EML4–ALK-positive NSCLC with EGFR mutation that had a response of stable disease to both single-agent EGFR-TKI and ALK inhibitor. EML4–ALK translocation may be associated with resistance to EGFR-TKI, and EGFR signaling may contribute to resistance to ALK inhibitor in EML4–ALK-positive NSCLC.

Seedling leiomyoma of the esophagus and esophagogastric junction zone

The esophagus was totally excised for histopathological examination in 276 autopsy cases and 66 surgical cases (total, 342 cases). Leiomyoma of the esophagus was observed in 27 of the 342 cases. The tumors were present in 22 of the 225 male cases and in 5 of the 117 female cases. There were 38 leiomyomas among the 27 cases. Most of the leiomyomas originated in the inner circular muscle. None of the tumors was more than 7 mm. in length. Twenty-five of the 38 leiomyomas were located in the esophagogastric junction zone. Thus, subserial histological examination revealed leiomyomas at a higher frequency than that in previous reports.

FDG-PET/CT in the diagnosis of recurrent breast cancer

Background An advantage of PET/CT has been demonstrated for diagnosis of several tumor entities. In patients with breast cancer, early diagnosis and accurate restaging of recurrence after surgery is important for selection of the most appropriate therapeutic strategy. Purpose To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using 18F-fluorodeoxyglucose (FDG), for follow-up of patients with suspected recurrent breast cancer. Material and Methods Forty-seven patients with suspected recurrent breast cancer underwent PET/CT. The PET and PET/CT images were interpreted without knowledge of the results of other diagnostic modalities, and compared with each other with reference to the final diagnosis. Results Twenty-five (53%) patients suffered tumor recurrence. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT were 96%, 91%, 92%, 95%, and 94%, respectively. In comparison with PET, PET/CT had a higher sensitivity and accuracy (96% vs. 80% and 94% vs. 81%, respectively). The difference in diagnostic accuracy between PET/CT and PET was significant (P < 0.05). Conclusion The present findings indicate that PET/CT is an accurate, sensitive and reliable modality for screening and detection of breast cancer recurrence. PET/CT appears to be an effective surveillance tool, as it is able to cover the whole body in a single procedure and shows good performance.

Renal thrombotic microangiopathy associated with chronic graft‐versus‐host disease after allogeneic hematopoietic stem cell transplantation

Thrombotic microangiopathy (TMA) is a major complication after hematopoietic stem cell transplantation (HSCT). In this study, we examined the clinical and pathologic features of 2 patients and 5 autopsy cases with HSCT‐associated renal TMA to clarify the association between graft‐versus‐host disease (GVHD) and renal TMA. The median interval between HSCT and renal biopsy or autopsy was 7 months (range 3–42 months). Clinically, acute and chronic GVHD occurred in 7 and 4 patients, respectively. Clinical evidence for TMA was detected in 2 patients, while chronic kidney disease developed in all patients. The main histopathological findings were diffuse endothelial injury in glomeruli, peritubular capillaries (PTCs), and small arteries. In addition, all cases showed glomerulitis, renal tubulitis, and peritubular capillaritis with infiltration of CD3+ T cells and TIA‐1+ cytotoxic cells, suggesting that GVHD occurred during the development of TMA. Diffuse and patchy C4d deposition was noted in glomerular capillaries and PTCs, respectively, in 2 biopsy and 2 autopsy cases, suggesting the involvement of antibody‐mediated renal endothelial injury in more than 50% of renal TMA cases. In conclusion, the kidney is a potential target of chronic GVHD that may induce the development of HSCT‐associated TMA. Importantly, some cases are associated with chronic humoral GVHD.