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There are no clinical reports of long‐term follow‐up after carbon‐ion radiotherapy (CIRT) using a dose of 51.6 Gy (relative biological effectiveness [RBE]) in 12 fractions for localized prostate cancer, or of a comparison of clinical outcomes between passive and scanning beam irradiation. A total of 256 patients with localized prostate cancer who received CIRT at a dose of 51.6 Gy (RBE) in 12 fractions using two different beam delivery techniques (passive [n = 45] and scanning [n = 211]), and who were followed for more than 1 year, were analyzed. The biochemical relapse‐free (bRF) rate was defined by the Phoenix definition, and the actuarial toxicity rates were evaluated using the Kaplan‐Meier method. Of the 256 patients, 41 (16.0%), 111 (43.4%), and 104 (40.6%) were classified as low, intermediate, and high risk, respectively, after a median follow‐up of 7.0 (range 1.1‐10.4) years. Androgen deprivation therapy was performed in 212 patients (82.8%). The 5‐year bRF rates of the low‐, intermediate‐, and high‐risk patients were 95.1%, 90.9%, and 91.1%, respectively. The 5‐year rates of grade 2 late gastrointestinal and genitourinary toxicities in all patients were 0.4% and 6.3%, respectively. No grade ≥3 toxicities were observed. There were no significant differences in the rates of bRF or grade 2 toxicities in patients who received passive irradiation versus scanning irradiation. Our long‐term follow‐up results showed that a CIRT regimen of 51.6 Gy (RBE) in 12 fractions for localized prostate cancer yielded a good therapeutic outcome and low toxicity rates irrespective of the beam delivery technique., A 51.6 Gy (relative biological effectiveness) carbon‐ion radiotherapy regimen in 12 fractions for localized prostate cancer with long‐term follow‐up yielded a good therapeutic outcome and low toxicity rates in both passive and scanning beam irradiation without significant difference.

There are no studies on the risk factors of radiation pneumonitis (RP) after carbon-ion radiotherapy at a dose of 50 Gy (relative biological effectiveness (RBE)) in a single fraction. The objective of this study was to identify factors associated with RP after radiotherapy, including dose–volume parameters. Ninety-eight patients without a history of thoracic radiotherapy who underwent treatment for solitary lung tumors between July 2013 and April 2016 were retrospectively analyzed. Treatment was planned using Xio-N. The median follow-up duration was 53 months, and the median clinical target volume was 32.3 mL. Three patients developed grade 2 RP, and one patient developed grade 3 interstitial pneumonitis. None of the patients developed grade 4 or 5 RP. The dose-volume parameters of the normal lung irradiated at least with 5–30 Gy (RBE), and the mean lung dose was significantly lower in patients with grade 0–1 RP than in those with grade 2–3 RP. Pretreatment with higher SP-D and interstitial pneumonitis were significant factors for the occurrence of symptomatic RP. The present study showed a certain standard for single-fraction carbon-ion radiotherapy that does not increase the risk of RP, however, further validation studies are needed.

Purpose/Objective(s) 70% of patients able to receive surgical resection for pancreatic adenocarcinoma may ultimately experience recurrence; 25-35% have disease in the remnant pancreas or tumor bed. Surgical re-resection carries notable risks for morbidity, while success with photon irradiation has been limited. Carbon-ion radiotherapy (CIRT) has demonstrated unique promise in the treatment of locally advanced pancreatic cancer (LAPC). An initial cohort from 2011-2015 was published in 2017; here, we provide an update on CIRT safety and efficacy for post-surgical salvage of locally recurrent pancreatic cancer, with 60 cases from 2007 to 2020. Materials/Methods Patients with locoregional recurrence following resection of pancreatic cancer were eligible. CIRT was conducted using 48.0 to 55.2 Gy (RBE) in 12 fractions, delivered over 3 weeks. Inclusion criteria included: 1) unresectable disease due to tumor invasion or patient refusal of re-resection; 2) absence of distant metastasis, 3) ECOG performance of 0 to 2. Patients with disease invading the GI tract, previous radiotherapy, or metallic stent placement were excluded. Results A total of 60 patients treated between January 2007 and 2020 were retrospectively reviewed. Median age was 65, with pancreatic head primary in 34 cases and body/tail in 26 cases. 34 cases underwent pancreaticoduodenectomy, with 26 distal pancreatectomies. 14 cases recurred in the residual pancreas, while 46 cases recurred in surrounding tissue. 16 cases received 48 – 52.8 Gy (RBE) via dose escalation, with 44 cases receiving 55.2 Gy (RBE). Grade 3 hematologic toxicity was seen in 3 cases, with no other G3+ acute or late toxicity was noted. 2-year local control was achieved in 56% for 48-52.8 Gy (RBE) and 61% for 55.2 Gy (RBE) cohorts. 2-year survival was 48% in the high dose cohort, with median survival time (MST) of 23 months. Conclusion CIRT for postoperative recurrence of pancreatic cancer compared favorably to conventional chemoradiation salvage (2-year survival 38%, 16-month MST), with acceptable toxicity. CIRT may be a viable treatment alternative when re-resection is difficult.

Long-term outcomes after surgical resection of bile duct cancer remain unsatisfactory, and survival, particularly after tumor recurrence, is poor. Gemcitabine and cisplatin combination (GC) therapy is the standard first-line treatment; however, second-line approaches are yet to be established. Radiotherapy may prolong the survival of patients with advanced biliary tract cancer, and particle radiotherapy delivers a more concentrated dose than conventional radiotherapy to deeper tumors. The present report describes the long-term survival of a 65-year-old man with distal bile duct cancer of pathological stage IIA (T2N0M0; depth of invasion, 5.5 mm) following multimodal treatment. Following subtotal stomach-preserving pancreatoduodenectomy, multiple hepatic recurrences were identified 9 months later, and GC therapy was initiated. The tumors were no longer evident 18 months later, and GC therapy was discontinued at the patient's request. A computed tomography (CT) scan performed 30 months after surgery identified a new solitary hepatic recurrence and duke pancreatic monoclonal antigen type-2 (DUPAN-2) levels were increased. Further GC therapy was declined. Carbon ion radiotherapy (CIRT) at a dose of 60 Gy [relative biological effectiveness (RBE)-weighted absorbed dose] was then delivered in four fractions over 4 days [15 Gy (RBE)/day]. Tumor size decreased on CT, and fluorodeoxyglucose-positron emission tomography/CT revealed a decline in the standardized uptake value of the tumor after 2 months, with decreased DUPAN-2 levels. Following regrowth of the hepatic recurrence, CIRT was repeated at a dose of 66 Gy (RBE) in four fractions over 4 days [16.5 Gy (RBE)/day] and stable disease was maintained for 19 months. After 19 months, CT revealed tumor regrowth and another new metastatic lesion was identified in the left kidney. The patient received systematic chemotherapy again and died of the disease 81 months after the initial surgery. In conclusion, CIRT is a potential treatment option to control solitary recurrence of biliary tract cancer.

Aim Evaluation of the therapeutic efficacy of carbon-ion radiation therapy for isolated lymph node recurrence following curative resection of esophageal cancer. Materials and methods Ten cases with lymph node recurrence after esophageal cancer surgery were treated with carbon-ion radiation therapy. A total of 48.0 Gy [relative biologic effectiveness (RBE)] was delivered over 3 weeks with a daily dose of 4.0 Gy (RBE). Results The median follow-up duration was 27.1 months (range=3-92.0 months) after carbon-ion radiation therapy. The local control rates at 2, 3 and 5 years were 92.4%. The overall survival rates at 2, 3 and 5 years were 70.0%, 58.3% and 21.9%. The median survival period was 45.3 months after carbon-ion radiation therapy. There were no toxicities of grade 3 or higher. Conclusion Carbon-ion radiation therapy may be a safe and effective treatment option for isolated lymph node recurrence after radical surgery for esophageal cancer.

Purpose The aim of this multi-institutional study was to evaluate the efficacy and safety of carbon-ion radiotherapy (C-ion RT) for locally advanced pancreatic cancer (LAPC). Methods and Materials Patients with LAPC treated with C-ion RT from April 2012 to December 2014 at 3 institutions were retrospectively analyzed. Patients with pathologically-confirmed invasive ductal adenocarcinoma of the pancreas were eligible. The prescribed dose was 52.8 Gy (relative biological effectiveness weighted absorbed dose; RBE) or 55.2 Gy (RBE) in 12 fractions. Overall survival (OS), distant metastasis-free survival (DMFS), local recurrence (LR), and toxicity were evaluated. Results In total, 72 patients were included in this study. Tumors in the head of the pancreas were seen in 30 patients (42%), while those in the body or tail of the pancreas were seen in 42 patients (58%). Fifty-six patients (78%) received concurrent chemotherapy. The OS rates were 73% (95% confidence interval [CI], 62%-84%) at 1 year, and 46% (95% CI, 31%-61%) at 2 years with a median OS of 21.5 months (95% CI, 11.8-31.2 months). The 1- and 2-year DMFS rates were 41% (95% CI, 29%-52%) and 28% (95% CI, 16%-40%), respectively. The 1- and 2-year cumulative incidences of LR were 16% (95% CI, 9%-26%) and 24% (95% CI, 14%-36%), respectively. Nineteen patients (26%) experienced acute grade 3 or 4 hematological toxicities. Two patients (3%) had grade 3 anorexia. Late gastrointestinal (GI) grade 3 toxicity was observed in 1 patient (1%). No patients developed late grade 4 or 5 toxicity. Conclusions The first multi-institutional analysis of C-ion RT for LAPC indicated relatively favorable outcomes with limited toxicities, especially for tumors not in close proximity to GI tract.

Background: The purpose of the present study was to evaluate the efficacy and safety of single-fraction carbon-ion radiotherapy (CIRT) in patients with non-small cell lung cancer. Methods: Patients with histologically confirmed non-small cell lung cancer, stage T1-2N0M0, and treated with single-fraction CIRT (50Gy (relative biological effectiveness)) between June 2011 and April 2016 were identified in our database and retrospectively analyzed. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events version 4.0. Results: The study included 57 patients, 22 (38.6%) of whom had inoperable cancer. The median age was 75 years (range: 42&ndash, 94 years), and the median follow-up time was 61 months (range: 6&ndash, 97 months). The 3- and 5-year overall survival rates were 91.2% and 81.7%, respectively. All survivors were followed up for more than three years. The 3- and 5-year local control rates were 96.4% and 91.8%, respectively. No case of &ge, grade 2 pneumonitis was recorded. Conclusions: This study suggests that single-fraction CIRT for T1-2N0M0 non-small cell lung cancer patients is feasible and can be considered as one of the treatment choices, especially in medically inoperable patients.

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. 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. 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. 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.

The aim of this study was to clarify the importance of microRNA‑375 (miR‑375) expression in patients with esophageal squamous cell carcinoma (ESCC) and to examine the in vivo antitumor effects of miR‑375 in a model of ESCC using a non‑viral delivery system. We estimated the miR‑375 and LDHB and AEG‑1/MTDH mRNA expression of the ESCC tumors from 85 patients. The correlation between the miR‑375 expression and clinicopathological features, including the prognosis, were evaluated. The presence of high miR‑375 expression was associated with lymphatic vessel invasion, while a low expression of miR‑375 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 miR‑375 and that of LDHB. Before the examination of miR‑375 in the in vivo assay, we confirmed that atelocollagen prolonged the accumulation of miRNA by using fluorescently‑labeled miRNA and an in vivo imaging system. We injected the miR‑375/atelocollagen complex or a control‑miRNA/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 miR‑375 groups was significantly suppressed compared with that in the control‑miRNA groups. In addition, The LDHB mRNA expression of TE2 xenografts was significantly downregulated after miR‑375 treatment. In conclusion, it might be possible for the level of miR‑375 expression to be a utilized as a prognostic indicator for ESCC patients. The administration of miR‑375 using a non‑viral delivery might represent a powerful new treatment for ESCC.

The aim of this study was to assess whether modulated electro-hyperthermia (mEHT) can induce an abscopal effect and thereby enhance the antitumor effects of immunotherapy. We used an intratumoral dendritic cell (DC) injection and mEHT to treat C3H/He mice inoculated with squamous cell carcinoma SCCVII cells in the left leg, and we assessed the whole body antitumor effects. Tumors were examined every two or three days in order to assess growth inhibition. The tumor-draining lymph nodes were removed to enable flow cytometric analysis of CD3+ and CD8+ cells, whereas immunohistochemistry was used to assess CD8, S100 and Foxp3 expression in the tumors. Additionally, GP96 expression in the tumors from the different treatment groups was measured. In the control group, the mean tumor volume was larger than that in other groups. These results indicated that the combination therapy of an intratumoral DC injection and mEHT evoked systemic antitumor activity. A larger number of CD3+ and CD8+ cells were detected by flow cytometric analysis in the DC plus mEHT treatment group. Tumor tissue immunostaining showed that CD8 and S100 were more strongly expressed in the DC plus mEHT treatment group, although Foxp3 expression was much higher in the control group. The GP96 gene expression level in the mEHT group was significantly different from the expression level in the control group. An abscopal effect may be induced by mEHT, and the effect of immunotherapy with DCs was strongly enhanced by the overexpression of GP96. GP96 is thought to be one of the molecules explaining the abscopal effect. Direct intratumoral administration of DCs and mEHT may be a feasible future treatment strategy.

Cyclooxygenase-2 (COX-2) is a key enzyme of prostaglandin (PG) synthesis that has been demonstrated to be overexpressed in several types of cancers. The function of COX-2 in tumor progression has been recently elucidated. In tumors in which COX-2 is overexpressed, the antitumor effects are suppressed. We examined the effects of celecoxib, a COX-2 inhibitor, in enhancing the antitumor effects of chemotherapy and radiotherapy for esophageal squamous cell carcinoma (ESCC) by reducing the COX-2 activity. We used the human esophageal squamous cell lines TE2 and T.Tn treated with celecoxib and 5-FU/radiation, after which cell viability assays were performed. Changes in the expressions of dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) mRNA and PGE2 were also measured. In addition, apoptotic changes, and the invasion and migration activity in both the celecoxib and 5-FU treated cells were evaluated. The experiments showed that T.Tn and TE2 proliferation was strongly inhibited by the combination of 5-FU/radiation and the COX-2 inhibitor. Inhibiting the COX-2 activity induced a reduction in PGE2 levels in TE2/T.Tn cells. Following treatment with the COX-2 inhibitor and 5-FU, the OPRT expression was upregulated and the DPD expression was downregulated in the resistant cells. In addition, the combination treatment with the COX-2 inhibitor and 5-FU markedly inhibited both the cell invasion and migration activity. Therefore, COX-2 inhibitors can be useful enhancers of antitumor drugs and radiotherapy for ESCC.

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.

Background: FSCN1 and matrix metalloproteinase 14 (MMP14) are both invadopodia-related proteins. We herein elucidate the tumourigenicity of these proteins and identify novel therapeutic agents in esophageal squamous cell carcinoma (ESCC). Methods: FSCN1 and MMP14 were evaluated by immunohistochemistry and quantitative PCR, and microRNA (miR)-133a was also evaluated by PCR in surgical ESCC specimens. The roles of FSCN1, MMP14 and miR-133a were established in ESCC cells. Results: The expression of FSCN1 or MMP14 was an independent poor prognostic factor according to a multivariate analysis of immunohistochemistry, and their co-expression correlated with the poorest overall survival (OS) out of all the examined factors. Additionally, their mRNAs significantly correlated and both inversely correlated with miR-133a in surgical specimens. Transfection of a miR-133a mimic decreased the mRNA and protein levels of both FSCN1 and MMP14 in ESCC cells. The knockdown of FSCN1 or MMP14 and transfection of a miR-133a mimic inhibited the proliferation and invasion of ESCC cells. Patients with a lower miR-133a expression have a significantly poorer OS than those with a higher expression. Conclusion: The combined expression of FSCN1 and MMP14 is associated with a poor prognosis, and miR-133a, which regulates their mRNAs, can serve as a strong tumour suppressor of ESCC.

Background: Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in blood and can serve as useful biomarkers for cancer. Methods: We performed an miRNA array using serum samples obtained from oesophageal squamous cell carcinoma (ESCC) patients or healthy controls. MiR-1246 was the most markedly elevated in ESCC patients. Therefore, miR-1246 was selected as a candidate for further analysis. The serum miR-1246 level in 46 healthy controls and 101 ESCC patients was evaluated and compared among various clinicopathological characteristics. MiR-1246 expressions in tissue, exosomal, and cellular samples were also examined. Results: Serum miR-1246 alone yielded an receiver-operating characteristic curve area of 0.754, with 71.3% sensitivity and 73.9% specificity for distinguishing ESCC patients from healthy controls. Serum miR-1246 was significantly correlated with the TNM stage and showed to be the strongest independent risk factor for poor survival (HR, 4.032; P=0.017). Unlike the tendency shown in previous reports, miR-1246 was not upregulated in ESCC tissue samples. Furthermore, exosomal miR-1246 did not reflect the abundance in the cell of origin. Conclusion: These data support our contention that serum miR-1246 has strong potential as a novel diagnostic and prognostic biomarker in ESCC, and its releasing mechanism is selective and independent of tissue miRNA abundance.

The expression of microRNA-203 (miR-203) in esophageal squamous cell carcinoma (ESCC) tissues is remarkably lower than that in non‑ESCC tissues. We investigated how miR-203 could influence the development of ESCC cells. Our analyses revealed that miR-203 inhibited the migration and invasion of ESCC cells. Genome-wide gene expression data and target site inhibition assays showed that miR-203 appears to directly regulate LIM and SH3 protein 1 (LASP1). The knockdown of LASP1 resulted in inhibition of the migration and invasion of ESCC cells. Our results suggest that miR-203 and its target LASP1, may be associated with the progression of ESCC. In clinical ESCC specimens, the expression levels of miR-203, which were lower compared to those in normal tissues, were inversely correlated with the mRNA expression levels of LASP1. Moreover, we found that there was a significant correlation between the expression levels of miR-203 and the relapse‑free survival. The identification of a cancer network regulated by miR-203 could provide new insights into the potential mechanisms of the progression of ESCC.

Purpose Investigation of the treatment potential of carbon-ion radiation therapy in pelvic recurrence of rectal cancer. Methods and Materials A phase 1/2 dose escalation study was performed. One hundred eighty patients (186 lesions) with locally recurrent rectal cancer were treated with carbon-ion radiation therapy (CIRT) (phase 1/2: 37 and 143 patients, respectively). The relapse locations were 71 in the presacral region, 82 in the pelvic sidewalls, 28 in the perineum, and 5 near the colorectal anastomosis. A 16-fraction in 4 weeks dose regimen was used, with total dose ranging from 67.2 to 73.6 Gy(RBE); RBE-weighted absorbed dose: 4.2 to 4.6 Gy(RBE)/fraction. Results During phase 1, the highest total dose, 73.6 Gy(RBE), resulted in no grade >3 acute reactions in the 13 patients treated at that dose. Dose escalation was halted at this level, and this dose was used for phase 2, with no other grade >3 acute reactions observed. At 5 years, the local control and survival rates at 73.6 Gy(RBE) were 88% (95% confidence interval [CI], 80%-93%) and 59% (95% CI, 50%-68%), respectively. Conclusion Carbon-ion radiation therapy may be a safe and effective treatment option for locally recurrent rectal cancer and may serve as an alternative to surgery.

The aim of this study was to determine whether histone acetylation regulates tumor suppressive microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC) and to identify genes which are regulated by these miRNAs. We identified a miRNA that was highly upregulated in an ESCC cell line by cyclic hydroxamic acid-containing peptide 31 (CHAP31), one of the histone deacetylase inhibitors (HDACIs), using a miRNA array analysis. miR-375 was strongly upregulated by CHAP31 treatment in an ESCC cell line. The expression levels of the most upregulated miRNA, miR-375 were analyzed by quantitative real-time PCR in human ESCC specimens. The tumor suppressive function of miR-375 was revealed by restoration of miR-375 in ESCC cell lines. We performed a microarray analysis to identify target genes of miR-375. The mRNA and protein expression levels of these genes were verified in ESCC clinical specimens. LDHB and AEG-1/MTDH were detected as miR‑375-targeted genes. The restoration of miR-375 suppressed the expression of LDHB and AEG-1/MTDH. The ESCC clinical specimens exhibited a high level of LDHB expression at both the mRNA and protein levels. A loss-of-function assay using a siRNA analysis was performed to examine the oncogenic function of the gene. Knockdown of LDHB by RNAi showed a tumor suppressive function in the ESCC cells. The correlation between gene expression and clinicopathological features was investigated by immunohistochemistry for 94 cases of ESCC. The positive staining of LDHB correlated significantly with lymph node metastasis and tumor stage. It also had a tendency to be associated with a poor prognosis. Our results indicate that HDACIs upregulate miRNAs, at least some of which act as tumor suppressors. LDHB, which is regulated by the tumor suppressive miR-375, may therefore act as an oncogene in ESCC.

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.

69 Background: Recently, abscopal effect, by which systemic anti-tumor effect by local radiation therapy (RT) was elicited, has been reported. This phenomenon was thought to be mediated by stress protein gp96, a key molecule in antigen-presenting. We tested the enhancement of dendritic cell (DC) therapy by various stress, such as radiation or modulated electro-hyperthermia (mEHT) in DC therapy for squamous cell carcinoma (SCC). Methods: Mouse SCC cells, SCCVII, were inoculated into the left femur (primary tumor) of C3H/He mice subcutaneously, and also similarly inoculated into non-treated chest subcutaneous tissue (secondary tumor). Only the primary tumor was exposed to 4 or 10 Gy of RT or 5-10 watts of mEHT. Then DCs was injected only into the primary tumor. Following that, tumor volumes of the primary and secondary tumor were measured. Next, the population of immune-related T-cells in tumor-draining lymph nodes (TDLN) and gp96 expression in the primary tumor were evaluated. Results: With intratumoral injection of DCs and RT, primary tumor growth was markedly suppressed. Furthermore, secondary tumor growth was also suppressed. On the other hand, the combination of DCs and mEHT could inhibit tumor growth at both the primary and the secondary tumor. As for the population of T-cells, the population of CD3+, CD 4+ and CD 8+T-cells in the TDLN was markedly elevated and that of FoxP3 was reduced my mEHT. Gp96 expression, a stress protein, was strongly enhanced after RT and mEHT. Conclusions: Stress, such as RT or hyperthermia can enhance the efficacy of DC therapy and can induce a strong antitumor effect by stimulating the expression of stress protein, gp96. These combination therapies can be a strong systemic immunotherapy for esophageal SCC.