Adenovirus-mediated gene transfer into rat livers: comparative study of retrograde intrabiliary and antegrade intraportal administration

To examine the feasibility of liver-directed in vivo gene therapy, we administered recombinant adenoviruses carrying a reporter lacZ gene retrogradely into the common bile duct of rats, as well as antegradely into the portal vein. Transduction efficiency of the lacZ gene in the liver was estimated not only histochemically by X-gal staining, but also quantitatively by a chemiluminescent reporter gene assay. Retrograde infusion of adenoviruses into the common bile duct was shown to successfully induce transgene expression in the liver. Transduction efficiency induced by intrabiliary adenoviral administration was not significantly different from that induced by intraportal adenoviral administration. Although transgene expression induced not only by intraportal, but also by intrabiliary adenoviral administration was observed predominantly at periportal areas, a considerable number of cells expressing the transgene were detectable even in lobular and centrilobular areas. Mild infiltration of inflammatory cells into the liver and mild hyperplastic changes of hepatocytes were observed after intrabiliary and intraportal adenoviral administration. However, hepatic damage estimated pathologically was not substantial. Furthermore, although intrabiliary and intraportal adenoviral administration resulted in very mild elevation of liver-related serum biochemical parameters, apparent complications were not observed in any rats. Our results demonstrated in the present study suggest that retrograde administration of adenoviruses into the common bile duct can induce efficient transgene expression in the liver without causing severe adverse effects, supporting the feasibility of adenovirus-mediated gene transfer into the liver in clinical settings by means of endoscopic retrograde cholangiography.     

Establishment of a novel experimental model for muscle‐invasive bladder cancer using a dog bladder cancer organoid culture

In human and dogs, bladder cancer (BC) is the most common neoplasm affecting the urinary tract. Dog BC resembles human muscle‐invasive BC in histopathological characteristics and gene expression profiles, and could be an important research model for this disease. Cancer patient‐derived organoid culture can recapitulate organ structures and maintains the gene expression profiles of original tumor tissues. In a previous study, we generated dog prostate cancer organoids using urine samples, however dog BC organoids had never been produced. Therefore we aimed to generate dog BC organoids using urine samples and check their histopathological characteristics, drug sensitivity, and gene expression profiles. Organoids from individual BC dogs were successfully generated, expressed urothelial cell markers (CK7, CK20, and UPK3A) and exhibited tumorigenesis in vivo. In a cell viability assay, the response to combined treatment with a range of anticancer drugs (cisplatin, vinblastine, gemcitabine or piroxicam) was markedly different in each BC organoid. In RNA‐sequencing analysis, expression levels of basal cell markers (CK5 and DSG3) and several novel genes (MMP28, CTSE, CNN3, TFPI2, COL17A1, and AGPAT4) were upregulated in BC organoids compared with normal bladder tissues or two‐dimensional (2D) BC cell lines. These established dog BC organoids might be a useful tool, not only to determine suitable chemotherapy for BC diseased dogs but also to identify novel biomarkers in human muscle‐invasive BC. In the present study, for the 1st time, dog BC organoids were generated and several specifically upregulated organoid genes were identified. Our data suggest that dog BC organoids might become a new tool to provide fresh insights into both dog BC therapy and diagnostic biomarkers.     

Early administration of pegfilgrastim for esophageal cancer treated with docetaxel,cisplatin, and fluorouracil: A phase II study

Preoperative or induction chemotherapy with docetaxel, cisplatin, plus 5‐fluorouracil (DCF) is a promising regimen for advanced esophageal cancer. However, the DCF regimen is associated with a high risk of severe neutropenia or febrile neutropenia (FN). However, the current guidelines fail to recommend an optimal dosing schedule of pegfilgrastim along with the DCF regimen to prevent FN. In the present study, we assessed the efficacy and safety of giving pegfilgrastim early on day 3 during DCF therapy for esophageal cancer. In this single‐arm phase II study, patients with squamous cell carcinoma of the esophagus were recruited. They were treated with the DCF therapy on days 1‐5, with pegfilgrastim given on day 3. Primary endpoint was the occurrence of grade 4 neutropenia. Secondary endpoints included the incidence of FN, grade 3 neutropenia, dose delays/reductions, antitumor effect, and safety. Between July 2016 and December 2018, 23 patients were enrolled. The incidence of grade 4 neutropenia was 8.7% (95% confidence interval 1.1%‐28.0%). No patient experienced FN. Of the 19 patients who received two cycles of DCF, one required a dose reduction/treatment delay due to hematological toxicity in the second treatment cycle. No serious adverse events, considered relevant to pegfilgrastim, were observed. This is the first prospective study that showed an efficacious dosing schedule of pegfilgrastim for preventing hematological toxicity during DCF therapy. The results might be generalized to other similar regimens where continuous infusions of 5‐fluorouracil are used.     

Prolonged treatment with three-weekly docetaxel plus daily prednisolone for metastatic castration-resistant prostate cancer: a multicenter, phase II, open-label, non-comparative, extension study in Japan

Background

There are few reports of long-term treatment with docetaxel in castration-resistant prostate cancer (CRPC) because of the limit of a maximum of ten cycles of treatment in TAX327 showing a survival benefit. Therefore, this study, ARD6563, was conducted to evaluate the safety of more than ten cycles of docetaxel in metastatic CRPC.

Methods

We enrolled patients who had received ten cycles of docetaxel in the preceding study, ARD6562. For ARD6563, patients received docetaxel every 3 weeks, at the last dose (70, 60, or 50 mg/m²) received for cycle 10 in ARD6562, with prednisolone 5 mg orally twice daily.

Results

The safety analysis set comprised 15 patients (median age, 64 years; performance status, 0 in 87%) out of 43 patients treated in ARD6562. The median initial dose of docetaxel was 60 mg/m², and the median number of additional cycles administered was 8 (range, 1–42). The relative dose intensity was 78.0% for docetaxel and 98.0% for prednisolone. Dose reduction was needed in 3 cycles because of grade 3 infection, febrile neutropenia, and grade 2 neuropathy. Administration delay was necessitated in 6 cycles because of grade 1–2 nonhematological toxicities. The major grade 3–4 toxicities were myelosuppression. Five patients who had an observed partial response or stable disease in ARD6562 maintained their clinical response in ARD6563. The study treatment was discontinued in 10 patients because of disease progression and in 4 patients for serious toxicities. There were no treatment-related deaths.

Conclusions

Long-term docetaxel with prednisolone is feasible in selected Japanese patients with CRPC.     

Characterization of common marmoset dysgerminoma‐like tumor induced by the lentiviral expression of reprogramming factors

Recent generation of induced pluripotent stem (iPSCs) has made a significant impact on the field of human regenerative medicine. Prior to the clinical application of iPSCs, testing of their safety and usefulness must be carried out using reliable animal models of various diseases. In order to generate iPSCs from common marmoset (CM; Callithrix jacchus), one of the most useful experimental animals, we have lentivirally transduced reprogramming factors, including POU5F1 (also known as OCT3/4), SOX2, KLF4, and c-MYC into CM fibroblasts. The cells formed round colonies expressing embryonic stem cell markers, however, they showed an abnormal karyotype denoted as 46, X, del(4q), +mar, and formed human dysgerminoma-like tumors in SCID mice, indicating that the transduction of reprogramming factors caused unexpected tumorigenesis of CM cells. Moreover, CM dysgerminoma-like tumors were highly sensitive to DNA-damaging agents, irradiation, and fibroblast growth factor receptor inhibitor, and their growth was dependent on c-MYC expression. These results indicate that DNA-damaging agents, irradiation, fibroblast growth factor receptor inhibitor, and c-MYC-targeted therapies might represent effective treatment strategies for unexpected tumors in patients receiving iPSC-based therapy.     

Union for International Cancer Control International Session: Healthcare Economics: The significance of the UN summit non‐communicable diseases political declaration in Asia

The Japan National Committee for the Union for International Cancer Control (UICC) and UICC‐Asia Regional Office (ARO) organized an international session as part of the official program of the 71st Annual Meeting of the Japanese Cancer Association to discuss the topic “Healthcare Economics: The Significance of the UN Summit non‐communicable diseases (NCDs) Political Declaration in Asia.” The presenters and participants discussed the growing cost of cancer in the Asian region and the challenges that are faced by the countries of Asia, all of which face budgetary and other systemic constraints in tackling and controlling cancer in the region. The session benefited from the participation of various stakeholders, including cancer researchers and representatives of the pharmaceutical industry. They discussed the significance of the UN Political Declaration on the prevention and control of NCDs (2011) as a means of boosting awareness of cancer in the Asian region and also addressed the ways in which stakeholders can cooperate to improve cancer control and treatment. Other issues that were covered included challenges relating to pharmaceutical trials in Asia and how to link knowledge and research outcomes. The session concluded with the recognition that with the onset of a super‐aged society in most countries in Asia and an increasing focus on quality of life rather than quantity of life, it is more important than ever for all stakeholders to continue to share information and promote policy dialogue on cancer control and treatment.     

Ultrasound demonstration of mammographically detected microcalcifications in patients with ductal carcinoma<Emphasis Type="Italic">in situ</Emphasis> of the breast

BACKGROUND: Breast microcalcifications are difficult to depict by ultrasound (US). However, recent advances in US equipment and the refinement of breast imaging techniques have improved the detection and characterization of small breast lesions. The present study attempts to determine whether US examination is able to demonstrate nonpalpable breast lesions associated with mammographically detected microcalcifications without mass density or distortion, and to evaluate the clinical reliability of US-guided procedures, especially in cases of ductal carcinoma in situ(DCIS)of the breast. METHODS: The subjects consisted of 73 patients with breast cancer diagnosed preoperatively as DCIS by stereotactic core needle biopsies, all of whom had microcalcifications without other abnormalities on mammography. The radiological appearance and size of the clustered microcalcifications were evaluated. US examinations were performed preoperatively, and the detection rates were assessed. Sonographically detected lesions underwent US-guided wire localization followed by surgical excision. RESULTS: The lesions associated with microcalcifications were identified sonographically in 54 of 73 cases (74%), and the pathological examination revealed breast cancer in all of the corresponding specimens. Lesions with linear-branching shape, segmental-linear distribution and category-5 calcifications on mammography had a high level of visibility on US. The US visible cases had a larger size of calcified area on mammography when compared with US invisible cases. Pathologically, the lesions were more frequently seen on US in cases with minimally invasive cancer or with comedo type DCIS. CONCLUSIONS: US examination is an effective method for identifying and localizing breast microcalcifications, and can be used as an alternative to stereotactic localization in selected patients with early breast cancer.