Kosuke Fujino

A novel minimally invasive near-infrared thoracoscopic localization technique of small pulmonary nodules: A phase I feasibility trial

Objectives Localization and resection of nonvisible, nonpalpable pulmonary nodules during video‐assisted thoracoscopic surgery are challenging. Our study was to determine the feasibility and safety of indocyanine green fluorescence localization and resection of small nodules using a near‐infrared fluorescence thoracoscope. Methods Twenty patients with undiagnosed peripheral nodules smaller than 3 cm scheduled for computed tomography–guided microcoil placement followed by video‐assisted thoracoscopic surgery wedge resection were enrolled. After microcoil deployment, 100 to 150 &mgr;L of diluted indocyanine green was injected percutaneously near the nodule. The nodule initially was localized solely by using a near‐infrared thoracoscope to visualize indocyanine green fluorescence. Thoracoscopic instruments were used to determine the staple line. Wedge resection was performed after confirmation of the location of the microcoil using fluoroscopy. Results Twenty patients underwent near‐infrared, image‐guided, video‐assisted thoracoscopic surgery resection. The median computed tomography tumor size was 1.2 cm. The median depth from the pleural surface was 1.4 cm (range, 0.2‐4.8 cm). The median computed tomography–guided intervention time was 35 minutes, and video‐assisted thoracoscopic surgery procedural time was 54 minutes. Indocyanine green fluorescence was clearly identified in 18 of 20 patients (90%). The surgical margins were all negative on final pathology without the need for additional resection. The final diagnoses included 18 primary lung cancers, 1 metastatic lung cancer, and 1 benign lung tumor. Conclusions Computed tomography–guided percutaneous indocyanine green injection and intraoperative near‐infrared localization of small nodules are safe and feasible. These offer surgeons the ease of localization through direct indocyanine green fluorescence imaging without the use of fluoroscopy and may be a complementary technique to preoperative microcoil placement for nonvisible, nonpalpable intrapulmonary nodules.

Nanoparticle targeted folate receptor 1-enhanced photodynamic therapy for lung cancer

OBJECTIVE Despite modest improvements, the prognosis of lung cancer patients has still remained poor and new treatment are urgently needed. Photodynamic therapy (PDT), the use of light-activated compounds (photosensitizers) is a treatment option but its use has been restricted to central airway lesions. Here, we report the use of novel porphyrin-lipid nanoparticles (porphysomes) targeted to folate receptor 1 (FOLR1) to enhance the efficacy and specificity of PDT that may translate into a minimally-invasive intervention for peripheral lung cancer and metastatic lymph nodes of advanced lung cancer. MATERIALS AND METHODS The frequency of FOLR1 expression in primary lung cancer and metastatic lymph nodes was first analyzed by human tissue samples from surgery and endobronchial ultrasonography-guided transbronchial needle aspiration (EBUS-TBNA). Confocal fluorescence microscopy was then used to confirm the cellular uptake and fluorescence activation in lung cancer cells, and the photocytotoxicity was evaluated using a cell viability assay. In vivo fluorescence activation and quantification of uptake were investigated in mouse lung orthotopic tumor models, followed by the evaluation of in vivo PDT efficacy. RESULTS FOLR1 was highly expressed in metastatic lymph node samples from patients with advanced lung cancer and was mainly expressed in lung adenocarcinomas in primary lung cancer. Expression of FOLR1 in lung cancer cell lines corresponded with the intracellular uptake of folate-porphysomes in vitro. When irradiated with a 671nm laser at a dose of 10J/cm2, folate-porphysomes showed marked therapeutic efficacy compared with untargeted porphysomes (28% vs. 83% and 24% vs. 99% cell viability in A549 and SBC5 lung cancer cells, respectively). Systemically-administered folate-porphysomes accumulated in lung tumors with significantly enhanced disease-to-normal tissue contrast. Folate-porphysomes mediated PDT successfully inhibited tumor cell proliferation and activated tumor cell apoptosis. CONCLUSION Folate-porphysome based PDT shows promise in selectively ablating lung cancer based on FOLR1 expression in these preclinical models.

Targeting non-small cell lung cancer by novel TLD-1433-mediated photodynamic therapy (Conference Presentation)

Background: The majority of cancers upregulate their transferrin receptor (Tf-R) to satisfy their higher Fe3+ requirements for proliferation. TLD-1433 can bind to transferrin to form Rutherrin, which is a promising photosensitizer with stable chemical structure and higher tissue selectivity. Methods: To investigate the effect of Rutherrin®-mediated photodynamic treatment (PDT), we used non-small lung cancer cell lines H2170, A549, and H460. Subcutaneous tumors were treated with Rutherrin-mediated PDT, 4hrs post intravenous administration. The treatment parameters10 mg/kg Rutherrin and 600 Jcm-2 808 nm radiation. In an orthotopic A549 tumor model, the presence of tumor after inoculation in lungs was confirmed by microCT. Tissue samples were collected for Inductively Coupled Mass Spectrometry to quantify the Rutherrin concentrations via a Ru isotope in tumor and normal lung tissue. Results: Evaluation of TfR expression by flow cytometric and western blotting showed that almost all cancer cells express TfR. In in-vitro cytotoxicity assay, all cancer cell lines showed high cell kill by PDT at 100nM Rutherrin concentrations. In the subcutaneous tumor model, PDT after Rutherrin injection significantly inhibited the tumor growth and histopathology showed extensive necrosis at 24 hrs, which was confirmed with lowered Ki67 staining. In an orthotopic model, the lung lobe with tumor retained more Rutherrin than the contralateral lung, showing specific tumor uptake. Conclusion: These results support the hypothesis that safe and efficient Rutherrin-mediated PDT is feasible due to improved photosensitizer localization to lung tumors tissue. Selective irradiation of the cancer lesions by strategic placement of the light source remains a requirement.

Personalized siRNA-Nanoparticle Systemic Therapy using Metastatic Lymph Node Specimens Obtained with EBUS-TBNA in Lung Cancer

Inhibiting specific gene expression with siRNA provides a new therapeutic strategy to tackle many diseases at the molecular level. Recent strategies called high-density lipoprotein (HDL)-mimicking peptide-phospholipid nanoscaffold (HPPS) nanoparticles have been used to induce siRNAs-targeted delivery to scavenger receptor class B type I receptor (SCARB1)-expressing cancer cells with high efficiency. Here, eight ideal therapeutic target genes were identified for advanced lung cancer throughout the screenings using endobronchial ultrasonography–guided transbronchial needle aspiration (EBUS-TBNA) and the establishment of a personalized siRNA-nanoparticle therapy. The relevance of these genes was evaluated by means of siRNA experiments in cancer cell growth. To establish a therapeutic model, kinesin family member-11 (KIF11) was selected as a target gene. A total of 356 lung cancers were analyzed immunohistochemically for its clinicopathologic significance. The antitumor effect of HPPS-conjugated siRNA was evaluated in vivo using xenograft tumor models. Inhibition of gene expression for these targets effectively suppressed lung cancer cell growth. SCARB1 was highly expressed in a subset of tumors from the lung large-cell carcinoma (LCC) and small-cell lung cancer (SCLC) patients. High-level KIF11 expression was identified as an independent prognostic factor in LCC and squamous cell carcinoma (SqCC) patients. Finally, a conjugate of siRNA against KIF11 and HPPS nanoparticles induced downregulation of KIF11 expression and mediated dramatic inhibition of tumor growth in vivo. Implications: This approach showed delivering personalized cancer-specific siRNAs via the appropriate nanocarrier may be a novel therapeutic option for patients with advanced lung cancer. Mol Cancer Res; 16(1); 47–57. ©2017 AACR.

Clinical evaluation of the utility of a flexible 19-gauge EBUS-TBNA needle

Background Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established modality for the assessment of mediastinal and hilar adenopathy. To overcome the sampling limitations of standard 21- and 22-gauge EBUS-TBNA needles, a new flexible 19-gauge (Flex 19G) needle was developed. Methods We performed a retrospective analysis of patients who underwent EBUS-TBNA sampling with the Flex 19G needle. A 22G needle was always used first for cytology, followed by a Flex 19G needle, either an early version (Oct/2014-Sep/2015) or a final version needle (May/2016-Jan/2017), for tissue sampling. The success rate of obtaining samples, specimen quantity, and safety were evaluated and compared. Results All sampling procedures in 45 patients and 82 targets were performed without complication and the overall diagnostic yield from cytology was 100%. Furthermore, 28% of Flex 19G samples were sufficient for histopathological diagnosis. Yield improved with an increased number of passes and if the target was larger. Compared to the early version evaluated in 52 targets, the final version of the Flex 19G needle evaluated in 30 targets provided significantly larger volume samples and more frequent diagnostic cores. Tissue obtained with the Flex 19G needle retained cohesiveness to a larger degree and was of higher cellularity compared to cytological samples processed as cell blocks. Conclusions The Flex 19G is safe and provides larger volumetric and cohesive tissue samples that are appropriate for histopathological processing. The final version of the Flex 19G could be a good choice in selected cases where greater tissue acquisition is required.

Preclinical investigation of folate receptor-targeted nanoparticles for photodynamic therapy of malignant pleural mesothelioma

Photodynamic therapy (PDT) following lung- sparing extended pleurectomy for malignant pleural mesothelioma (MPM) has been investigated as a potential means to kill residual microscopic cells. High expression levels of folate receptor 1 (FOLR1) have been reported in MPM; therefore, targeting FOLR1 has been considered a novel potential strategy. The present study developed FOLR1-targeting porphyrin-lipid nanoparticles (folate-porphysomes, FP) for the treatment of PDT. Furthermore, inhibition of activated epidermal growth factor (EGFR)-associated survival pathways enhance PDT efficacy. In the present study, these approaches were combined; FP-based PDT was used together with an EGFR-tyrosine kinase inhibitor (EGFR-TKI). The frequency of FOLR1 and EGFR expression in MPM was analyzed using tissue microarrays. Confocal microscopy and a cell viability assay were performed to confirm the specificity of FOLR1-targeting cellular uptake and photocytotoxicity in vitro. In vivo fluorescence activation and therapeutic efficacy were subsequently examined. The effects of EGFR-TKI were also assessed in vitro. The in vivo combined antitumor effect of EGFR-TKI and FP-PDT was then evaluated. The results revealed that FOLR1 and EGFR were expressed in 79 and 89% of MPM samples, respectively. In addition, intracellular uptake of FP corresponded well with FOLR1 expression. When MPM cells were incubated with FP and then irradiated at 671 nm, there was significant in vitro cell death, which was inhibited in the presence of free folic acid, thus suggesting the specificity of FPs. FOLR1 targeting resulted in disassembly of the porphysomes and subsequent fluorescence activation in intrathoracic disseminated MPM tumors, as demonstrated by ex vivo tissue imaging. FP-PDT resulted in significant cellular damage and apoptosis in vivo. Furthermore, the combination of pretreatment with EGFR-TKI and FP-PDT induced a marked improvement of treatment responses. In conclusion, FP-based PDT induced selective destruction of MPM cells based on FOLR1 targeting, and pretreatment with EGFR-TKI further enhanced the therapeutic response.