Effect of combination therapy with a novel bisphosphonate, minodronate (YM529), and docetaxel on a model of bone metastasis by human transitional cell carcinoma.

PURPOSE: Transitional cell carcinoma (TCC) of the urinary tract is a chemosensitive tumor. Most deaths from TCC of the urinary tract are caused by metastasis, which is resistant to conventional chemotherapy. Frequent sites of metastases from TCC of the urinary tract are regional lymph nodes, liver, lung, and bone. Of these distant metastases, bone metastasis is consistently resistant to cisplatin-based conventional chemotherapy. Therefore, in this study, we investigated whether or not a newly developed minodronate, YM529, could prevent osteolytic bone metastasis of human TCC and also enhance the effect of docetaxel in a bone tumor model of athymic nude mice. EXPERIMENTAL DESIGN: In the present study, we evaluated the effect of in vitro treatment with minodronate and/or docetaxel on the proliferation by cell count, the induction of apoptosis by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and the biological activity of osteoclast by pit formation assay in human bladder cancer cell line, UMUC-14, and mouse osteoclast cells. In vivo, we examined the effect of minodronate in a bone tumor model of athymic nude mice, in which the percutaneous intraosseal injection in the tibia of UMUC-14, leads to osteolytic bone tumor, as a bone metastasis model. To examine whether or not minodronate could inhibit tumorigenicity and enhance the effect of the chemotherapeutic agent, docetaxel, we gave minodronate i.p. and/or docetaxel i.p. to nude mice 3 days after an intraosseal tumor implantation. Moreover, proliferation and the induction of apoptosis of cancer cells and osteoclasts in bone tumors were determined by immunohistochemistry and the TUNEL assay. RESULTS: In vitro: In vitro treatment with docetaxel inhibited proliferation and resorption pit-forming activity and induced apoptosis of mouse osteoclast cells and UMUC-14 cells. In vitro treatment with minodronate inhibited proliferation and activity and induced apoptosis of mouse osteoclast cells but not UMUC-14 cells. The treatment with minodronate enhanced the inhibition of proliferation and activity by docetaxel in osteoclasts. In vivo: In vivo combination therapy with docetaxel and minodronate significantly reduced the tumor incidence compared with the control (P < 0.05) and also growth of intraossal TCC in athymic nude mice compared with the control (P < 0.001), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). Drug-induced body weight loss was not significantly different in any treatment group. Therapy with minodronate significantly enhanced inhibition of proliferation by docetaxel in osteoclasts of bone tumors compared with the control (P < 0.01), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). CONCLUSIONS: These studies indicate that combination therapy with minodronate and docetaxel may be beneficial in patients with bone metastasis of human TCC in the urinary tract.     

Diagnostic and prognostic role of urinary collagens in primary human bladder cancer

Collagen type 4 alpha 1 (COL4A1) and collagen type 13 alpha 1 (COL13A1) produced by urothelial cancer cells support the vital oncogenic property of tumor invasion. We investigated the diagnostic and prognostic capability of COL4A1 and COL13A1 in voided urine and compared the observed values with those of fragments of cytokeratin‐19 (CYFRA21‐1), nuclear matrix protein 22 (NMP‐22), and voided urine cytology in bladder cancer (BCa). We collected voided urine samples from 154 patients newly diagnosed with BCa, before surgery and from 61 control subjects. Protein levels of COL4A1, COL13A1, CYFRA21‐1, and NMP‐22 in urine supernatants were measured using enzyme‐linked immunosorbent assays. Diagnostic performance and optimal cut‐off values were determined by receiver operating characteristic analysis. Urine levels of COL4A1, COL13A1, the combined values of COL4A1 and COL13A1 (COL4A1 + COL13A1), and CYFRA21‐1 were significantly elevated in urine from patients with BCa compared to the controls. Among these biomarkers, the optimal cut‐off value of COL4A1 + COL13A1 at 1.33 ng/mL resulted in 57.4%, 83.7%, 56.1%, 80.7%, and 91.7% sensitivity for low‐grade tumors, high‐grade tumors, Ta, T1, and muscle invasive disease, respectively. We evaluated the prognostic value of preoperative urine levels in 130 non‐muscle invasive BCa samples after the initial transurethral surgery. A high urinary COL4A1 + COL13A1 was found to be an independent risk factor for intravesical recurrence. Although these data need to be externally validated, urinary COL4A1 and COL13A1 could be a potential diagnostic and prognostic biomarker for BCa. This easy‐to‐use urinary signature identifies a subgroup of patients with a high probability of recurrence and progression in non‐muscle invasive and muscle invasive BCa.     

A gastrointestinal stromal tumor in the stomach: usefulness of computed tomographic volumetry

We report herein the case of a 70-year-old man who was found to have a gastrointestinal stromal tumor (GIST) in the stomach following sigmoid colon resection. Preoperative gastroscopic and barium examinations revealed a submucosal tumor, measuring 10cm, on the upper part of the stomach. Using computed tomography (CT) images (i.e., computed tomographic volumetry) the doubling time of this tumor was calculated, accurately, as 3.3 months, which suggested a high growth rate and malignancy. A laparotomy and partial gastric resection were performed. Histologically, the tumor consisted of spindle-shaped cells with oval nuclei. In immunohistochemical studies, the tumor cells were positive with respect to c-kit, CD34, and vimentin, but negative with respect to smooth muscle actin and S-100 protein. There were 15–16 mitoses per 50 high-power fields (HPFs), and the Ki-67 antigen (MIB-1) index was 25.5% in the most active areas, which also indicated malignancy. The final pathological diagnosis of this tumor was malignant GIST. The patient was found to have hepatic metastasis 27 months after the surgery, and he subsequently received a hepatic subsegmentectomy. To our knowledge, there are very few reports concerning the growth rate of GISTs. Computed tomographic volumetry is useful for the follow-up of small or irregularly shaped gastric submucosal tumors, and for making decisions regarding surgical intervention.     

Induction of Extrahepatic Biliary Carcinoma by N-Nitrosobis(2-oxopropyl)amine in Hamsters Given Cholecystoduodenostomy with Dissection of the Common Duct

The methods we used to produce a carcinoma in the extrahepatic bile duct and gallbladder in hamsters are described along with the characteristics of the induced tumors. Female Syrian golden hamsters were first subjected to Cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CDDB) and were, 4 weeks later, treated with weekly subcutaneous injections of N-nitrosobis(2-oxopropyl)amine (BOP) at a dose of 10 mg/kg body weight for 9 weeks. The animals were killed at the 12th, 16th and 20th week after the initiation of BOP treatment. Extrahepatic bile duct carcinoma developed in 16%, 24% and 41% and gallbladder carcinoma occurred in 58%, 81% and 82% of the hamsters, respectively, at the corresponding times of killing. The incidences were significantly higher than those in sham-operated controls ( P <0.01). The induced extrahepatic bile duct carcinomas were predominantly of the polypoid type and gallbladder carcinomas were of the papillary type in growth form, being morphologically similar to early stage biliary carcinoma in humans. Immunohistochemical staining using bromodeoxynridine and anti-bromo-deoxyuridine monoclonal antibody demonstrated that the CDDB procedure greatly accelerated the cell kinetic activity of the biliary epithelium, and this was considered to be a major factor promoting the development of biliary carcinomas in this hamster model. In conclusion, this new model provides a high incidence of tumor development at the extrahepatic biliary tract and is expected to be useful for clarifying the characteristics of this highly malignant tumor.     

Hepatocellular Carcinoma Induction in LEC Rats by a Low Dose of 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline

A food-borne heterocyclic amine, 2-amino-3,8-dimethylimidazo[4,5- f ]qninoxaline (MeIQx), induces hepatocellular carcinomas (HCCs) in F344 male rats at an incidence of 95%, when fed in the diet at 400 ppm for 61 weeks. In this study, the effect of a low dose of MeIQx was examined in Long-Evans with cinnamon-like coat color (LEC) rats, which have a mutation in Atp7b and suffer from hereditary hepatitis and HCCs, with high levels of copper accumulation in the liver. Rats of the LEC and Long-Evans with agouti coat color (LEA) sibling lines were given a diet containing 40 ppm MeIQx from the age of 23 weeks to 63 weeks, for a total administration period of 40 weeks. In LEC rats, HCCs were observed in 8/8 animals administered MeIQx, and 2/8 rats receiving a normal diet. The number of HCCs per rat (mean±SD) was 2.8±2.0 and 0.3±0.5, respectively. In the LEA rats, however, no tumors were induced by administration of MeIQx. These results indicate that damaged liver associated with compensatory cell proliferation is much more susceptible to chemical hepatocarcinogens, including MeIQx, than the normal liver.     

Molecular pathogenesis of pediatric astrocytic tumors

Astrocytomas are the most common pediatric brain tumors, accounting for 7%-8% of all childhood cancers. Relatively few studies have been performed on their molecular properties; therefore, classification of pediatric astrocytic tumors into genetic subtypes similar to that of adult tumors remains to be defined. Here, we report an extensive characterization of 44 pediatric astrocytomas--16 diffuse astrocytomas (WHO grade II), 10 anaplastic astrocytomas (WHO grade III), and 18 glioblastomas (WHO grade IV)--in terms of genetic alterations frequently observed in adult astrocytomas. Some form of p53 mutation was found in three diffuse astrocytomas, in three anaplastic astrocytomas, and in six glioblastomas examined; PTEN mutations were detected only in two glioblastomas. EGFR amplification was detected in only one anaplastic astrocytoma and two glioblastomas, but no amplification was observed for the PDGFR-alpha gene. Loss of heterozygosity (LOH) on 1p/19q and 10p/10q was less common in pediatric astrocytic tumors than in those seen in adults, but the frequency of LOH on 22q was comparable, occurring in 44% of diffuse astrocytomas, 40% of anaplastic astrocytomas, and 61% of glioblastomas. Interestingly, a higher frequency of p53 mutations and LOH on 19q and 22q in tumors from children six or more years of age at diagnosis was found, compared with those from younger children. Our results suggest some differences in children compared to adults in the genetic pathways leading to the formation of de novo astrocytic tumors. In addition, this study suggests potentially distinct developmental pathways in younger versus older children.     

O6-Methylguanine-DNA Methyltransferase (MGMT) as a Determinant of Resistance to Camptothecin Derivatives

The precise mechanisms of resistance to camptothecin (CPT)-derived DNA topoisomerase (topo I) inhibitors and the determinants remain unclear. We found that a DNA repair protein, O⁶-methylguanine-DNA methyltransferase(MGMT), participated in resistance to irinotecan hydrochloride (CPT-11), its active metabolite SN-38, and a novel CPT derivative, DX-8951f. In 17 human cancer cell lines, MGMT gene expression level closely correlated with sensitivity to the CPT derivatives, and inhibition of MGMT activity by nontoxic 5 μM O⁶-benzylguanine augmented the drug activity in relation to the MGMT expression levels in 8 cell lines examined. Transfection of pCR/MGMT-sense into U-251MG and pCR/MGMT-antisense into T98G and HEC-46 cells revealed that increased MGMT expression decreased the sensitivity to CPT-11, SN-38, and DX-8951f, whereas repressed MGMT expression sensitized cells to the drugs. Western analysis revealed that treatment of MGMT -expressing T98G cells with the drugs caused a decrease of both MGMT and topo I in a dose-dependent manner. Although, in the transfectants, MGMT expression did not so closely correlate with the sensitivity to drugs as to nimustine hydrochloride (ACNU), MGMT is probably an important resistance determinant to CPT derivatives, and may play some role in the topo I-mediated DNA damage and/or the repair process.     

Feeding jejunostomy following esophagectomy may increase the occurrence of postoperative small bowel obstruction

This study aimed to clarify the characteristics and treatment of bowel obstruction associated with feeding jejunostomy in patients who underwent esophagectomy for esophageal cancer. In this single-center retrospective study, 363 patients underwent esophagectomy with mediastinal lymph node dissection for esophageal cancer at the Wakayama Medical University Hospital between January 2014 and June 2021. All patients who underwent esophagectomy routinely underwent feeding jejunostomy or gastrostomy. Feeding jejunostomy was used in the cases of gastric tube reconstruction through the posterior mediastinal route or colon reconstruction, while feeding gastrostomy was used in cases of retrosternal route gastric tube reconstruction. Nasogastric feeding tubes and round ligament technique were not used. Postoperative small bowel obstruction occurred in 19 of 197 cases of posterior mediastinal route reconstruction (9.6%), but in no cases of retrosternal route reconstruction because of the feeding gastrostomy (P < .0001). Of the 19 patients who had bowel obstruction after feeding jejunostomy, 10 patients underwent reoperation (53%) and the remaining 9 patients had conservative treatment (47%). The cumulative incidence of bowel obstruction after feeding jejunostomy was 6.7% at 1 year and 8.7% at 2 years. Feeding jejunostomy following esophagectomy is a risk factor for small bowel obstruction. We recommend feeding gastrostomy inserted from the antrum to the jejunum in the cases of gastric tube reconstruction through the retrosternal route or nasogastric feeding tube in the cases of reconstruction through the posterior mediastinal route.     

Deep-learning classifier with ultrawide-field fundus ophthalmoscopy for detecting branch retinal vein occlusion

AIM: To investigate and compare the efficacy of two machine-learning technologies with deep-learning (DL) and support vector machine (SVM) for the detection of branch retinal vein occlusion (BRVO) using ultrawide-field fundus images. METHODS: This study included 237 images from 236 patients with BRVO with a mean±standard deviation of age 66.3±10.6y and 229 images from 176 non-BRVO healthy subjects with a mean age of 64.9±9.4y. Training was conducted using a deep convolutional neural network using ultrawide-field fundus images to construct the DL model. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) were calculated to compare the diagnostic abilities of the DL and SVM models. RESULTS: For the DL model, the sensitivity, specificity, PPV, NPV and AUC for diagnosing BRVO was 94.0% (95%CI: 93.8%-98.8%), 97.0% (95%CI: 89.7%-96.4%), 96.5% (95%CI: 94.3%-98.7%), 93.2% (95%CI: 90.5%-96.0%) and 0.976 (95%CI: 0.960-0.993), respectively. In contrast, for the SVM model, these values were 80.5% (95%CI: 77.8%-87.9%), 84.3% (95%CI: 75.8%-86.1%), 83.5% (95%CI: 78.4%-88.6%), 75.2% (95%CI: 72.1%-78.3%) and 0.857 (95%CI: 0.811-0.903), respectively. The DL model outperformed the SVM model in all the aforementioned parameters (P<0.001). CONCLUSION: These results indicate that the combination of the DL model and ultrawide-field fundus ophthalmoscopy may distinguish between healthy and BRVO eyes with a high level of accuracy. The proposed combination may be used for automatically diagnosing BRVO in patients residing in remote areas lacking access to an ophthalmic medical center.