TIP60 is required for tumorigenesis in non-small cell lung cancer.

Histone modifications play crucial roles in transcriptional activation, and aberrant epigenetic changes are associated with oncogenesis. Lysine (K) acetyltransferases 5 (TIP60, also known as KAT5) is reportedly implicated in cancer development and maintenance, although its function in lung cancer remains controversial. Here we demonstrate that TIP60 knockdown in non-small cell lung cancer cell lines decreased tumor cell growth, migration, and invasion. Furthermore, analysis of a mouse lung cancer model with lung-specific conditional Tip60 knockout revealed suppressed tumor formation relative to controls, but no apparent effects on normal lung homeostasis. RNA-seq and ChIP-seq analyses of inducible TIP60 knockdown H1975 cells relative to controls revealed transglutaminase enzyme (TGM5) as downstream of TIP60. Investigation of a connectivity map database identified several candidate compounds that decrease TIP60 mRNA, one that suppressed tumor growth in cell culture and in vivo. In addition, TH1834, a TIP60 acetyltransferase inhibitor, showed comparable antitumor effects in cell culture and in vivo. Taken together, suppression of TIP60 activity shows tumor-specific efficacy against lung cancer, with no overt effect on normal tissues. Our work suggests that targeting TIP60 could be a promising approach to treating lung cancer.

Fundic Gland Polyps Lack DNA Content Abnormality Characteristic of Other Adenomatous Precursor Lesions in the Gastrointestinal Tract.

Fundic gland polyps (FGPs) develop sporadically (frequently after proton pump inhibitor therapy) or in the setting of a hereditary polyposis syndrome, such as familial adenomatous polyposis (FAP). FAP-related FGPs often demonstrate low-grade dysplasia (LGD) and are frequently associated with APC mutations, even in the absence of dysplasia. Sporadic FGPs with dysplasia are molecularly similar to FAP-related FGPs and demonstrate frequent mutations in APC gene. Despite having similar molecular alterations with colorectal and other adenomatous precursor lesions in the gastrointestinal (GI) tract, FGPs rarely progress to advanced gastric neoplasia (high-grade dysplasia [HGD] or adenocarcinoma), and their role in gastric tumorigenesis remains unclear but likely limited. The clinicopathologic features of 192 patients diagnosed with FGPs, including 86 with FAP-related FGPs (33 with dysplastic FGPs and 53 with nondysplastic FGPs) and 106 with sporadic FGPs (12 with dysplastic FGPs and 94 with nondysplastic FGPs), were analyzed. DNA flow cytometry was performed on 111 FAP-related FGP biopsies, including 32 FGPs with LGD and 79 nondysplastic FGPs, to assess the presence of abnormal DNA content (ie, aneuploidy or elevated 4N fraction). Moreover, 40 sporadic FGP biopsies, including 14 dysplastic (13 LGD and 1 HGD) and 26 nondysplastic FGPs, were examined for DNA content abnormality. Patients with FAP and nondysplastic FGPs were more likely to be younger (mean age, 32 years) and present with multiple FGPs (92%, defined as having ≥2 FGPs) than those with sporadic nondysplastic FGPs (61 years and 65%, respectively; P < .001). They also recorded higher rates of previous or concurrent gastric epithelial dysplasia not occurring in a FGP (8%, P = .016), nongastric GI dysplasia (96%, P < .001), and nongastric GI malignancy (17%, P = .001) compared with those with sporadic nondysplastic FGPs (0%, 52%, and 2%, respectively). The sporadic group was more frequently associated with proton pump inhibitor therapy (78%, P < .001), gastric intestinal metaplasia (24%, P = .004), and a family history of gastric cancer (10%, P = .027) than the FAP group (19%, 6%, and 0%, respectively). Almost all FAP-related FGPs had a polypoid endoscopic appearance (98% vs 84% for sporadic FGPs; P = .009). The mean size of the largest FAP-related FGPs (0.5 cm) was similar to that of sporadic FGPs (0.7 cm) (P = .069). None of the 147 patients with FAP-related or sporadic nondysplastic FGPs were associated with subsequent detection of advanced gastric neoplasia within a mean follow-up time of 54 months (range, <1 to 277 months). However, 2 (4%) of the 45 patients with FAP-related or sporadic dysplastic FGPs developed advanced gastric neoplasia within a mean follow-up time of 59 months (range, <1 to 236 months). One (3%) of the 33 patients with FAP and dysplastic FGPs developed signet ring cell adenocarcinoma, whereas 1 (8%) of the 12 patients with sporadic dysplastic FGPs developed HGD (P = .445). However, none of the FAP-related and sporadic FGP biopsies, regardless of the presence or absence of dysplasia, demonstrated DNA content abnormality. In conclusion, FGPs lack large-scale chromosomal changes that are characteristic of the typical adenoma-carcinoma sequence involved in the development of other GI malignancies. Progression to advanced gastric neoplasia is rare in FGPs, which may be partly explained by the apparent lack of the chromosomal instability phenotype in these lesions.

Fra-1 Regulates the Expression of HMGA1, Which is Associated with a Poor Prognosis in Human Esophageal Squamous Cell Carcinoma.

BACKGROUND: The expression of Fos-related antigen 1 (Fra-1) affects tumor progression, migration, and invasion. In this study, we identified the genes regulated by Fra-1 in esophageal squamous cell carcinoma (ESCC). METHODS: We constructed Fra-1 knockdown models via the transfection of small interfering RNA (siRNA) into ESCC cell lines (TE10, TE11). The expression levels of the genes in the knockdown models were analyzed using a microarray and a Biobase Upstream Analysis, while the expression levels of the candidate genes in the primary tumors of surgical specimens obtained from ESCC patients were determined using real-time polymerase chain reaction (PCR) and immunohistochemical staining. The clinicopathological features were then analyzed. RESULTS: The Biobase Upstream Analysis showed the high-mobility-group protein-1 (HMGA1) to be a significant gene regulated by Fra-1. Actual binding of Fra-1 to the promotor region of HMGA1 was revealed in subsequent chromatin immunoprecipitation PCR experiments. Patients with a positive HMGA1 expression had a poor prognosis, and a multivariate analysis demonstrated a positive HMGA1 expression to be a significant independent prognostic factor. CONCLUSION: HMGA1 is regulated by Fra-1 in ESCC, and the HMGA1 expression is significantly associated with a poor prognosis in ESCC patients. Downregulation of the HMGA1 expression may become a practical treatment strategy against ESCC in the future.

Histone Demethylase LSD1 Inhibitors Prevent Cell Growth by Regulating Gene Expression in Esophageal Squamous Cell Carcinoma Cells.

BACKGROUND: The expression of genes can be influenced by the balance of histone acetylation and/or histone demethylation, with an imbalance of these processes possibly observed in many cancers. The histone demethylase LSD1 inhibitor activity is associated with selective transcriptional regulation and alterations in the gene expression. However, the exact mechanisms underlying the antitumor effects of LSD1 inhibitors are not fully understood. METHODS: The antitumor effects of NCL1, an LSD1 inhibitor, in esophageal squamous cell cancer (ESCC) cell lines were evaluated. A comprehensive analysis of the changes in the gene expression in ESCC cell lines induced by NCL1 was carried out using a microarray analysis. A loss-of-function assay using a siRNA analysis was performed to examine the oncogenic function of the gene. RESULTS: NCL1 strongly inhibited the cell growth of T.Tn and TE2 ESCC cells and induced apoptosis. According to the microarray analysis, 81 genes in the T.Tn cells and 149 genes in the TE2 cells were up- or down-regulated 2-fold or more by NCL1 exposure. Among these genes, 27 were contained in both cell lines and exhibited similar expression patterns. PHLDB2, one of the genes down-regulated by NCL1, was overexpressed in the ESCC tumor tissues. Moreover, a high expression level of PHLDB2 was found to be significantly correlated with poor prognosis. CONCLUSIONS: The present observations of the comprehensive analysis of the gene expression levels provide insight into the mechanisms underlying the antitumor effects of LSD1 inhibitors in ESCC patients.

Giant esophageal gastrointestinal stromal tumor: report of a case.

Gastrointestinal stromal tumors (GISTs) rarely arise in the esophagus, where carcinoma is the most common malignant neoplasm and leiomyoma is the most common benign tumor. Because of their rarity, the clinical course and treatment of esophageal GISTs are poorly understood. These lesions are generally thought to carry a poor prognosis, making the differential diagnosis of other common mesenchymal neoplasms essential, for both prognostic and therapeutic reasons. We report a case of successfully resected giant esophageal GIST, thought to be the largest resected GIST reported in Japan. The patient was a 65-year-old woman, in whom upper gastrointestinal endoscopy found a 180-mm submucosal tumor in the lower thoracic esophagus, extending just below the aortic arch. We diagnosed esophageal GIST, and the patient underwent middle and lower esophagectomy via left thoracotomy, followed by gastric tube reconstruction. The tumor was resected completely. Histopathological and immunohistochemical staining confirmed that the tumor was a high-risk lesion, and treatment with imatinib was initiated. Computed tomography showed liver metastasis 5 months later, but the patient is doing well 24 months after surgery.

Screening of alternative drugs to the tumor suppressor miR-375 in esophageal squamous cell carcinoma using the connectivity map.

OBJECTIVE: The aim of this study was to identify alternative compounds to the tumor suppressor miR-375 using the connectivity map (CMAP) and to validate the antitumor effects of the identified drugs in esophageal squamous cell carcinoma (ESCC). METHODS: Gene profiling of miR-375-treated TE2 and T.Tn cells was applied in order to search the CMAP database. Among the compounds identified using the CMAP, we focused on 8 drugs [(-)-epigallocatechin-3-gallate, metformin, rosiglitazone among others], excluding 2 drugs among the top 10 compounds. We evaluated whether these compounds possess tumor-suppressive functions in ESCC. RESULTS: A cytotoxicity assay showed that the sensitivity of TE2 and T.Tn cells treated with the 8 compounds was evaluated based on IC50 values of 42.9 µM to 3.8 mM. A cell cycle analysis revealed that the percentage of TE2 and T.Tn cells incubated with 6 compounds in the G0/G1 phase or the G2/M phase increased by approximately 40-80%. A TUNEL assay showed that the percentages of apoptotic cells treated with almost all compounds were significantly increased (p < 0.05) compared with the control cells. CONCLUSION: The CMAP database is a useful tool for identifying compounds affecting the same molecular pathways, particularly products that are difficult to apply via practical approaches, such as microRNAs.

Incidence, risk factors and treatment outcomes of extravasation of cytotoxic agents in an outpatient chemotherapy clinic.

OBJECTIVE: Extravasation, the accidental leakage of an anticancer agent from a vessel into the surrounding tissues, can lead to irreversible local injuries and severe disability. Despite its considerable clinical importance, evidence-based information on extravasation in chemotherapy is lacking. This study characterized the clinical features of extravasation and identified issues to be resolved in current cancer chemotherapy performed in outpatient settings. METHODS: We retrospectively reviewed the medical charts of patients who received chemotherapy and sustained extravasation in our Outpatient Chemotherapy Clinic from April 2007 to August 2012. Chemotherapy administration and extravasation management procedures were standardized using the in-house chemotherapy guideline. RESULTS: Among 43 557 patients who received chemotherapy, 35 (0.08%) experienced extravasation. The duration between the start of infusion and extravasation was >2 h in 28 (80.0%) patients. The severity of extravasation was Grades 1, 2 and 3 in 28, 2 and 5 patients, respectively-three of whom were associated with port trouble. The contributing factor for extravasation was walking in 11 (31.4%) patients. All extravasations were cured without surgical intervention by management according to our guidelines. CONCLUSIONS: The incidence of extravasation is as low as 0.08%, using our in-house chemotherapy guideline. Extravasation from implanted ports tends to be severe.

Assessment of large droplet fat in frozen sections of donor liver biopsies: utility and interobserver variability of the newly described Banff method compared to a simplified Average of Fields method.

AIMS: There is great variability in the assessment and reporting of fat in frozen sections of donor liver biopsies. The Banff Working Group has proposed a novel method and definition for scoring large droplet fat (LDF) in donor liver biopsies. This study compares the Banff method with a simpler Average of Fields (AF) method and evaluates the impact of different LDF definitions. METHODS: Three pathologists assessed percentage of LDF (LDF%) in 10 donor liver biopsies using Banff and AF methods, applying the Banff LDF definition (cell distention with a single droplet larger than adjacent hepatocytes). Additionally, LDF% by the AF method was compared using two LDF definitions: Banff definition versus LDF definition 2 (single fat droplet occupying greater than half of a hepatocyte with nuclear displacement). RESULTS: Intraobserver concordance between the Banff and AF methods was similar for all three pathologists (kappa 0.76-1). Both methods exhibited 70% interobserver concordance, and there was substantial agreement (kappa 0.68) in the LDF% among the three pathologists for both methods. Comparing the two LDF definitions, results were significantly lower with the Banff definition; LDF >50% was observed in four cases with LDF definition 2 but none of the cases with the Banff definition. CONCLUSIONS: There is high interobserver and intraobserver concordance of LDF% between the Banff and AF methods. LDF% determined by the Banff definition was lower than with LDF definition 2, and needs to be validated based on graft outcome before it can be recommended for clinical use.

Reconstitution of human PDAC using primary cells reveals oncogenic transcriptomic features at tumor onset.

Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of human pancreatic acinar cells remains under debate. To address this gap in knowledge, we expand sorted human acinar cells as 3D organoids and genetically modify them through introduction of common PDAC mutations. The acinar organoids undergo dramatic transcriptional alterations but maintain a recognizable DNA methylation signature. The transcriptomes of acinar organoids are similar to those of disease-specific cell populations. Oncogenic KRAS alone do not transform acinar organoids. However, acinar organoids can form PDAC in vivo after acquiring the four most common driver mutations of this disease. Similarly, sorted ductal cells carrying these genetic mutations can also form PDAC, thus experimentally proving that PDACs can originate from both human acinar and ductal cells. RNA-seq analysis reveal the transcriptional shift from normal acinar cells towards PDACs with enhanced proliferation, metabolic rewiring, down-regulation of MHC molecules, and alterations in the coagulation and complement cascade. By comparing PDAC-like cells with normal pancreas and PDAC samples, we identify a group of genes with elevated expression during early transformation which represent potential early diagnostic biomarkers.

The overall prevalence of metastasis in T1 esophageal squamous cell carcinoma: a retrospective analysis of 295 patients.

OBJECTIVES: T1 esophageal squamous cell carcinoma (ESCC) has a low, but still present, risk of lymph node (LN) metastasis. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is often applied for T1 ESCC. To achieve successful treatment by EMR/ESD, the risk of LN metastases, LN recurrence, and hematological recurrence need to be better understood. The aim of this study was to determine the precise risk for metastasis in T1 ESCC. METHODS: We divided 295 patients with T1 ESCC who underwent surgery and/or ESD/EMR into 6 categories (m1, m2, m3, sm1, sm2, and sm3). Their risks of LN metastasis, LN recurrence, hematological recurrence, and the outcome were determined. RESULTS: The rates of LN metastasis and LN recurrence were 0% in m1 and m2, 9% in m3, 16% in sm1, 35% in sm2, and 62% in sm3 cases. The incidence of hematological recurrence was 0% in m1, m2, m3, and sm1 cases; 9% in sm2 cases; and 13% in sm3 cases. The overall risk of metastasis was 9% in m3, 16% in sm1, 38% in sm2, and 64% in sm3 patients. The 5-year disease-specific survival rates were 100% in m1, m2, and m3; 90.9% in sm1; 78.8% in sm2; and 68.6% in sm3 patients. Statistically, both lymphatic and venous invasion were selected as predictive markers for metastasis. In m3 patients, positivity for either of these had an odds ratio for metastasis of 7.333 (P = 0.093). CONCLUSIONS: Our study provides a precise assessment of the comprehensive risk of metastasis and feasible predictive markers for T1 ESCC.

Primary esophageal adenocarcinoma arising from heterotopic gastric mucosa: report of a case.

Adenocarcinoma arising from heterotopic gastric mucosa (HGM) is exceedingly rare. This report presents the case of a 57-year-old male who presented with the chief complaint of dysphagia. Endoscopy and computed tomography revealed a locally advanced tumor of the cervical esophagus and swollen mediastinal lymph nodes. He underwent chemoradiotherapy followed by esophagectomy with three-field lymph node dissection. The resected tumor was a circumferentially scarred lesion located 1.5 cm from the proximal margin. The tumor was identified to be a well-differentiated adenocarcinoma arising from HGM with invasion to the muscularis propria. Postoperative chemoradiotherapy was performed because positive surgical margins were observed in the resected tissue. The patient has remained alive for more than 4 years after surgery, without any evidence of recurrence.

The number of pathologic lymph nodes involved is still a significant prognostic factor even after neoadjuvant chemoradiotherapy in esophageal squamous cell carcinoma.

BACKGROUND: The correlation between the number of pathologic metastatic LNs in patients with esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemoradiotherapy (NACRT) and surgical outcome has rarely been reported. We evaluated the correlation between the number of pathologic metastatic lymph nodes (LNs) and the surgical outcome in ESCC after NACRT. METHODS: Eighty-eight patients with ESCC who underwent NACRT followed by surgery were evaluated. The clinical response of NACRT was evaluated and surgical specimens of the primary tumor and resected LNs were analyzed clinicopathologically. RESULTS: Fewer pathologic metastatic LNs was associated with better survival. According to the number of metastatic LNs, the difference in the median survival was the largest between the groups when patients were divided into those with 2 and 3 metastatic LNs (χ(2) : 13.694, P < 0.001). With regard to clinical factors, the initial N status prior to treatment had the most significant impact on survival by a univariate analysis (P = 0.064), and the number of pathologic metastatic LNs was a risk factor for poor survival, with a hazard ratio of 5.128 (95% C.I.: 1.438-18.285, P = 0.012) by a multivariate analysis. CONCLUSIONS: Of the various factors, the number of pathologic metastatic LNs was the strongest indicator to predict the patients' survival.

A phase 1/11 study of second-line chemotherapy with fractionated docetaxel and nedaplatin for 5-FU/cisplatin-resistant esophageal squamous cell carcinoma.

BACKGROUND/AIMS: There are few second-line regimens available for esophageal cancer. The use of fractionated docetaxel and nedaplatin as second-line chemotherapy was examined in this study. METHODOLOGY: Eligibility criteria were follows: histologically-proven squamous cell carcinoma, surgically unresectable disease, failure to respond to chemotherapy with 5-FU and cisplatin and no more than 2 prior chemotherapy regimens. A total of 12 patients were enrolled in this study. To reduce toxicities, fractionated docetaxel (50 mg/m² in day 1 and 8) and nedaplatin (50 mg/m² in day 8) were administered as second-line chemotherapy. RESULTS: Stable disease (SD) was observed in 4 cases (33%) and the disease control rate was 33%. Regarding toxicities, leukopenia was the most frequently observed (8 cases, 67%); however, there were no cases of grade 4 nonhematological toxicity. The 1-year overall survival was 26.7% and the median survival time was 7.8 months (95% CI=3.328-12.272 months). The 1-year progression-free survival was 0% and the median progression-free time was 2.0 months (95% CI=1.319-2.681). CONCLUSIONS: Combination chemotherapy using fractionated docetaxel and nedaplatin is safe and effective and appears to be a feasible regimen to use as second-line chemotherapy for FP-resistant advanced esophageal squamous cell carcinoma.

[The present state and task of the Palliative Care Team at Tokyo Women's Medical University Yachiyo Medical Center].

The palliative care team at Tokyo Women's Medical University Yachiyo Medical Center was established in April 2007. A meeting on palliative care has been held twice a month. The team received a total of 7 cases of consultation on the subject ranging from pain management control to a home care transition in the last 5 months. The team also held an unscheduled conference for the medical staff. After this, some of the tasks are thought to make our own manual of pain management, and to plan enlightenment activities for local doctors.

Paracrine Secretion of Transforming Growth Factor ß by Ductal Cells Promotes Acinar-to-Ductal Metaplasia in Cultured Human Exocrine Pancreas Tissues.

OBJECTIVE: We aimed to evaluate the contribution of acinar-to-ductal metaplasia (ADM) to the accumulation of cells with a ductal phenotype in cultured human exocrine pancreatic tissues and reveal the underlying mechanism. METHODS: We sorted and cultured viable cell populations in human exocrine pancreatic tissues with a flow cytometry-based lineage tracing method to evaluate possible mechanisms of ADM. Cell surface markers, gene expression pattern, and sphere formation assay were used to examine ADM. RESULTS: A large proportion of acinar cells gained CD133 expression during the 2-dimensional culture and showed down-regulation of acinar markers and up-regulation of ductal markers, assuming an ADM phenotype. In a serum-free culture condition, ADM induction was mainly dependent on transforming growth factor ß (TGF-ß) secreted from cultured ductal cells. Human acinar cells when cultured alone for a week in a serum-free condition do not undergo ADM. However, serum may contain other factors besides TGF-ß to induce ADM in human acinar cells. In addition, we found that TGF-ß cannot induce ADM of murine acinar cells. CONCLUSIONS: Ductal cells are the major source of TGF-ß that induces ADM in cultured human exocrine pancreatic tissues. This culture system might be a useful model to investigate the mechanism of ADM in human cells.

TGF-ß1 promotes acinar to ductal metaplasia of human pancreatic acinar cells.

Animal studies suggest that pancreatitis-induced acinar-to-ductal metaplasia (ADM) is a key event for pancreatic ductal adenocarcinoma (PDAC) initiation. However, there has not been an adequate system to explore the mechanisms of human ADM induction. We have developed a flow cytometry-based, high resolution lineage tracing method and 3D culture system to analyse ADM in human cells. In this system, well-known mouse ADM inducers did not promote ADM in human cells. In contrast, TGF-ß1 efficiently converted human acinar cells to duct-like cells (AD) in a SMAD-dependent manner, highlighting fundamental differences between the species. Functionally, AD cells gained transient proliferative capacity. Furthermore, oncogenic KRAS did not induce acinar cell proliferation, but did sustain the proliferation of AD cells, suggesting that oncogenic KRAS requires ADM-associated-changes to promote PDAC initiation. This ADM model provides a novel platform to explore the mechanisms involved in the development of human pancreatic diseases.

Usefulness of microRNA­375 as a prognostic and therapeutic tool in esophageal squamous cell carcinoma.

The aim of this study was to clarify the importance of microRNA­375 (miR­375) expression in patients with esophageal squamous cell carcinoma (ESCC) and to examine the in vivo antitumor effects of miR­375 in a model of ESCC using a non­viral delivery system. We estimated the miR­375 and LDHB and AEG­1/MTDH mRNA expression of the ESCC tumors from 85 patients. The correlation between the miR­375 expression and clinicopathological features, including the prognosis, were evaluated. The presence of high miR­375 expression was associated with lymphatic vessel invasion, while a low expression of miR­375 significantly correlated with a poor prognosis for the 85 ESCC patients. We also found that there was a significant inverse correlation between the expression of miR­375 and that of LDHB. Before the examination of miR­375 in the in vivo assay, we confirmed that atelocollagen prolonged the accumulation of miRNA by using fluorescently­labeled miRNA and an in vivo imaging system. We injected the miR­375/atelocollagen complex or a control­miRNA/atelocollagen complex into mice bearing TE2 and T.Tn xenografts via subcutaneous (s.c.) injections. The growth of both the TE2 and T.Tn tumors in the miR­375 groups was significantly suppressed compared with that in the control­miRNA groups. In addition, The LDHB mRNA expression of TE2 xenografts was significantly downregulated after miR­375 treatment. In conclusion, it might be possible for the level of miR­375 expression to be a utilized as a prognostic indicator for ESCC patients. The administration of miR­375 using a non­viral delivery might represent a powerful new treatment for ESCC.

Treatment of near-infrared photodynamic therapy using a liposomally formulated indocyanine green derivative for squamous cell carcinoma.

INTRODUCTION: Photodynamic therapy (PDT) is a less invasive option for cancer treatment that has evolved through recent developments in nanotechnology. We have designed and synthesized a novel liposome system that includes an indocyanine green (ICG) derivative, ICG-C18, in its bilayer. In addition to its use as an optical imager to visualize blood, lymphatic, and bile flow, ICG has also been used as an optical sensitizer. In the present report, we evaluate the use of our novel liposome system, LP-ICG-C18, in PDT for squamous cell carcinoma in an autologous murine model. MATERIALS AND METHODS: An excitation pulse beam (300 µJ/pulse) of a single band (800 nm) was used for sensitization. The cytotoxicity of the photodynamic therapy was evaluated in terms of cellular morphology changes, methyl thiazolyl tetrazolium (MTT) assay results, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining. We tested the enhanced permeability and retention effect of LP-ICG-C18 in tumor-bearing C3H/He mice using a near-infrared fluorescence imaging system and fluorescence microscopy. We also examined the antitumor effect of PDT by measuring tumor volume in tumor-bearing mice. RESULTS: Cell death and apoptosis were only observed in the PDT group receiving LP-ICG-C18. LP-ICG-C18 itself had no cytotoxic activity and showed good biocompatibility. LP-ICG-C18 accumulated on the tumor 24 hours after injection and was retained for approximately 3 weeks. Tumor cell apoptosis following PDT with LP-ICG-C18 was also observed under optical microscopy, MTT assay, and TUNEL staining. CONCLUSION: These findings suggest that LP-ICG-C18 may be an effective intervening material in PDT for malignant disease.

Detection of peritoneal dissemination with near-infrared fluorescence laparoscopic imaging using a liposomal formulation of a synthesized indocyanine green liposomal derivative.

BACKGROUND/AIM: Although conventional staging laparoscopy (SL) has improved the diagnostic accuracy of peritoneal dissemination, novel technology is needed to increase the sensitivity of SL. We herein describe a new imaging method employing near-infrared (NIR) fluorescence imaging using a liposomal synthesized indocyanine green (ICG) liposomal derivative, LP-ICG-C18. METHODS AND RESULTS: LP-ICG-C18 is a NIR-photoactivating probe in which an ICG fluorophore is covalently conjugated with a phospholipid moiety. Nude mice were intraperitoneally injected with gastric cancer cells. Twelve days later, the mice were given intravenous injections of LP-ICG-C18 at a dose of 0.15 mg/kg. A NIR imaging system was used to identify the disseminated tumors. The disseminated nodules in mice were detected without any difficulties. Disseminated tumor nodules were collected from mice with or without injections of liposomal formulation and were transferred into the swine peritoneal cavity. The nodules in the swine peritoneal cavity were clearly and promptly defined by the NIR imaging system. CONCLUSION: NIR-fluorescing liposomal probes can effectively target peritoneal disseminated tumors and can be easily detected by a NIR imaging system. These results warrant future clinical trials of our imaging system and may contribute to a more precise diagnosis and therapeutic approach for gastric cancer patients.