c-Met inhibitor upregulates E-cadherin, which is lost in portal vein tumor thrombus of hepatocellular carcinoma.

AIM: Portal vein tumor thrombus (PVTT) in hepatocellular carcinoma (HCC) is an essential therapeutic and prognostic factor. E-cadherin plays a crucial role in adhesive properties and intercellular interaction in various cancer tissues, including HCC, but the expression profile and functional contribution of E-cadherin in PVTT remain unknown. This study aimed to analyze the expression of E-cadherin in the main tumor tissue and PVTT tissue of HCC, and evaluate the functional roles of E-cadherin in PVTT formation. METHODS: A retrospective analysis was performed using the medical records of patients who underwent liver resection for HCC with PVTT, analyzing tissue specimens from 1995 to 2016. E-cadherin expression is evaluated using immunohistochemistry and western blot. The study also uses a c-Met inhibitor to explore its impact on E-cadherin expression in vitro and in vivo using cell lines and a tumor xenograft mouse model. RESULTS: The results revealed a reduced E-cadherin expression in PVTT tissue than in the main tumor tissue. The inhibition of c-Met activation, frequently detected in HCC, upregulated E-cadherin expression in HCC cell lines. Furthermore, treatment with c-Met inhibitors induced changes in epithelial morphology, and inhibited migration and invasion of HCC cell lines. CONCLUSIONS: This study demonstrates the downregulation of E-cadherin in PVTT, and underscores the potential of c-Met inhibition in upregulating E-cadherin and inhibiting metastatic behavior. Understanding the significance of E-cadherin and c-Met in HCC progression provides a foundation for future clinical investigations into the therapeutic effects of c-Met inhibitors on PVTT in HCC patients.

Genetic alteration of SLCO1B3 defines constitutional indocyanine green excretory defect in patients who underwent hepatectomy.

AIM: Constitutional indocyanine green (ICG) excretory defects must be distinguished when assessing liver function. The absence of OATP1B3 expression due to homogenous alterations in the SLCO1B3 gene has been recently reported to induce ICG excretory defects; however, its association with the clinical examinations and the clinical implications of heterogeneous SLCO1B3 gene alteration remain unclear. METHODS: OATP1B3 expression was evaluated in 49 patients who underwent hepatectomy after evaluation of the ICG retention rate at 15 min (ICGR15) and technetium-99 m-galactosyl serum albumin (99mTc-GSA) hepatic scintigraphy. Additionally, alterations in SLCO1B3 were analyzed in patients without OATP1B3 expression. Subsequently, 59 patients who underwent hepatectomy for colorectal liver metastasis (CRLM) were analyzed. RESULTS: Of 49 patients, 6 (12%) had absent OATP1B3 expression. They had significantly higher ICGR15 value (74.7% vs. 23.5%; p < 0.0001), better modified albumin-bilirubin (ALBI) grade (≤grade 2A, 100% vs. 42%; p = 0.010), more normal 99mTc-GSA hepatic scintigraphy (100% vs. 28%; p = 0.0003), and better pathological liver fibrosis (F0-1, 100% vs. 49%; p = 0.027) compared to those with OATP1B3 expression. Three available frozen blocks of cases without OATP1B3 expression showed homozygous alterations in SLCO1B3. Of 59 patients with CRLM in normal liver background, five (8.5%) had heterozygous insertion in SLCO1B3, however they had no difference in ICGR15 values or other clinical findings compared to the other patients. CONCLUSIONS: Constitutional ICG excretory defects may be defined by the complete absence of OATP1B3 expression. The modified ALBI grade and 99mTc-GSA hepatic scintigraphy were useful for detecting constitutional ICG excretory defects.

Knockdown of TFAP2E results in rapid G2/M transition in oral squamous cell carcinoma cells.

TFAP2E is a member of the activator protein-2 transcription factor family and acts as a tumor suppressor in several types of cancer. Downregulation of TFAP2E expression is significantly associated with a shorter overall survival period in patients with oral squamous cell carcinoma (OSCC). To evaluate the molecular mechanisms by which TFAP2E suppresses the development or progression of OSCC, the present study investigated the effects of TFAP2E downregulation on OSCC-derived Ca9-22 and HSC-4 cells. The present study demonstrated that small interfering RNA mediated-knockdown of TFAP2E accelerated the proliferation of these OSCC cell lines compared with that in the control group, as determined by the standard water-soluble tetrazolium salt-8 assay. To analyze the cell cycle progression rate, the cell cycle distribution patterns of TFAP2E-knockdown and control cells cultured in the presence of nocodazole, which prevents the completion of mitosis, were analyzed by fluorescence-activated cell sorting at different time points. When analyzing cellular DNA contents, no major differences in cell cycle profiles were observed; however, the rate of increase in cells positive for histone H3 Serine 28 phosphorylation, a standard molecular marker of early M phase, was significantly higher in TFAP2E-knockdown cells than in the control cells. Collectively, these results suggested that TFAP2E may attenuate the proliferation of OSCC cells by regulating G2/M transition.

Real-Time Fluorescence Imaging to Identify Cholangiocarcinoma in the Extrahepatic Biliary Tree Using an Enzyme-Activatable Probe.

Introduction: Complete resection is the only possible treatment for cholangiocarcinoma in the extrahepatic biliary tree (eCCA), although current imaging modalities are limited in their ability to accurately diagnose longitudinal spread. We aimed to develop fluorescence imaging techniques for real-time identification of eCCA using an enzyme-activatable probe, which emits fluorescence immediately after activation by a cancer-specific enzyme. Methods: Using lysates and small tissue fragments collected from surgically resected specimens, we selected the most specific probe for eCCA from among 800 enzyme-activatable probes. The selected probe was directly sprayed onto resected specimens and fluorescence images were acquired; these images were evaluated for diagnostic accuracy. We also comprehensively searched for enzymes that could activate the probe, then compared their expression levels in cancer and non-cancer tissues. Results: Analyses of 19 samples (four cancer lysates, seven non-cancer lysates, and eight bile samples) and 54 tissue fragments (13 cancer tissues and 41 non-cancer tissues) revealed that PM-2MeSiR was the most specific fluorophore for eCCA. Fluorescence images of 7 patients were obtained; these images enabled rapid identification of cancerous regions, which closely matched histopathology findings in 4 patients. Puromycin-sensitive aminopeptidase was identified as the enzyme that might activate the probe, and its expression was upregulated in eCCA. Conclusion: Fluorescence imaging with PM-2MeSiR, which may be activated by puromycin-sensitive aminopeptidase, yielded generally high accuracy. This technique may be useful for real-time identification of the spread of eCCA during surgery and endoscopic examinations.

Assessment of liver function-related mRNA expression and fluorescence imaging in outflow-obstructed regions in rats.

PURPOSE: The liver function in outflow-obstructed regions is reportedly impaired; however, the functional decrease has not been quantitatively assessed. We therefore evaluated the uptake of indocyanine green (ICG) into hepatocytes and the mRNA expression associated with the liver function in outflow-obstructed regions using rat models. METHODS: A total of 20 rats with the ligation of the right median hepatic vein to induce outflow obstruction were studied. Five rats each were grouped by the time of re-laparotomy, and the fluorescence intensity (FI) values of ICG. The mRNA expression, including that of Albumin, Cytochrome P450 (Cyp) 1a2, Cyp3a1, Cyp7a1, and Gamma-glutamylcysteine synthetase, in outflow-obstructed (mRNAOut-Ob) and non-outflow-obstructed (mRNANon) regions was assessed. RESULTS: Microscopic fluorescence imaging showed that the FI values were significantly lower in outflow-obstructed regions than in non-outflow-obstructed regions at 12 h, 24 h, and 3 days after ligation of the hepatic vein. The mRNAOut-Ob/mRNANon ratios decreased to approximately 30% at 12 h after the outflow obstruction and increased to approximately 70-80% at 7 days. CONCLUSIONS: The liver function in outflow-obstructed regions was impaired in terms of the uptake of ICG and the mRNA expression. Our findings may help estimate the postoperative functional remnant liver volume by considering the decrease in the liver function in outflow-obstructed regions.

The impact of the covalently closed circular DNA level on recurrence of hepatocellular carcinoma after initial hepatectomy: an analysis of patients with resolved hepatitis B virus infection.

BACKGROUND: We assessed whether or not covalently closed circular DNA (cccDNA) levels in the background liver influence the recurrence of hepatocellular carcinoma (HCC) in patients with resolved hepatitis B virus (HBV) infection. METHODS: Among 425 patients who underwent initial hepatectomy for HCC between 2010 and 2018, a retrospective review was performed in 44 with resolved HBV infection. The clinicopathologic characteristics were analyzed for correlation with tumor recurrence. The HBV cccDNA levels were tested via a droplet digital polymerase chain reaction assay. RESULTS: HBV cccDNA was detected in 27 of 44 patients (61%), and the median level was 1.0 copies/1000 ng (range, 0-931.3 copies/1000 ng). Anti-HBc ≥8.9 S/CO was associated with cccDNA detection (odds ratio, 11.08; 95% confidence interval [95% CI], 2.48-49.46; P = 0.002). Twenty-eight patients (64%) developed HCC recurrence after hepatectomy. The overall 3- and 5-year recurrence-free survival rates were 45.7% and 34.3%, respectively.19 HBV cccDNA levels was not significantly associated with HCC recurrence, while the presence of multiple tumors was an independent risk fact or (hazard ratio, 6.53; 95% CI, 2.48-17.19; P < 0.001. CONCLUSION: HBV cccDNA levels did not influence HCC recurrence after hepatectomy. Anti-HBc levels may be used as a surrogate marker for cccDNA.

Fluorescence Imaging Using Enzyme-Activatable Probes for Real-Time Identification of Pancreatic Cancer.

INTRODUCTION: Radical resection is the only curative treatment for pancreatic cancer, which is a life-threatening disease. However, it is often not easy to accurately identify the extent of the tumor before and during surgery. Here we describe the development of a novel method to detect pancreatic tumors using a tumor-specific enzyme-activatable fluorescence probe. METHODS: Tumor and non-tumor lysate or small specimen collected from the resected specimen were selected to serve as the most appropriate fluorescence probe to distinguish cancer tissues from noncancerous tissues. The selected probe was sprayed onto the cut surface of the resected specimen of cancer tissue to acquire a fluorescence image. Next, we evaluated the ability of the probe to detect the tumor and calculated the tumor-to-background ratio (TBR) by comparing the fluorescence image with the pathological extent of the tumor. Finally, we searched for a tumor-specific enzyme that optimally activates the selected probe. RESULTS: Using a library comprising 309 unique fluorescence probes, we selected GP-HMRG as the most appropriate activatable fluorescence probe. We obtained eight fluorescence images of resected specimens, among which four approximated the pathological findings of the tumor, which achieved the highest TBR. Finally, dipeptidyl-peptidase IV (DPP-IV) or a DPP-IV-like enzyme was identified as the target enzyme. CONCLUSION: This novel method may enable rapid and real-time visualization of pancreatic cancer through the enzymatic activities of cancer tissues.

Knockdown of E2F5 induces cell death via the TP53­dependent pathway in breast cancer cells carrying wild­type TP53.

E2F transcription factor 5 (E2F5) is a member of the E2F family of transcription factors, which are involved in regulation of various cellular processes, including cellular proliferation, apoptosis, differentiation and DNA damage response. Previously, we reported that E2F5 was aberrantly overexpressed in estrogen receptor (ER)­negative breast cancer, especially in triple­negative breast cancer (TNBC). In the present study, it was revealed that E2F5 gene silencing caused a significant reduction in the proliferation rate of breast cancer MCF7 (ER­positive luminal­type) and MDA­MB­231 (TNBC­type) cells. Additional experiments demonstrated that E2F5 knockdown triggered cell death of MCF7 cells but not MDA­MB­231 cells. As MCF7 and MDA­MB­231 cells carry wild­type and mutant TP53, respectively, and BT474 (ER­negative, HER2­positive type) carrying mutant TP53 exhibited similar results to MDA­MB­231, the possible effects of E2F5 gene depletion on cell death­related TP53­target gene expression were examined. Real­time RT­qPCR analysis revealed that knockdown of E2F5 in MCF7 cells stimulated cell death­related transcription of TP53­target genes such as BAX, NOXA and PUMA. For MDA­MB­231 and BT474 cells, E2F5 gene silencing revealed marginal effects on the expression of TP53 target genes. In addition, silencing of TP53 abrogated the effect of E2F5 silencing in MCF7 cells. Collectively, the present results indicated that E2F5 participated in the carcinogenesis of breast cancer carrying wild­type TP53 through suppression of TP53, while E2F5 had a pro­proliferative but not anti­apoptotic effect on breast cancer with TP53 mutation.

A neonatal case of HDR syndrome and a vascular ring with a novel GATA3 mutation.

HDR syndrome (OMIM #146255) is caused by haploinsufficiency of the GATA3 gene. A vascular ring has not been reported in patients with GATA3-associated HDR syndrome. We report a neonatal case of HDR syndrome and a vascular ring that were possibly due to a novel frameshift mutation in the GATA3 gene.

Silencing of EPHB2 promotes the epithelial-mesenchymal transition of skin squamous cell carcinoma-derived A431 cells.

Erythropoietin-producing hepatocellular (Eph) receptors and their ligand ephrins serve crucial roles in the interactions among epithelial cells. Eph receptor/ephrin signaling regulates cell functions, including proliferation, differentiation and migration, via these cell-cell interactions. We reported previously that EPHB2, a member of the Eph receptor family, was highly expressed in chemically induced cutaneous squamous cell carcinoma (cSCC) tissues in mice. Although the higher expression level of EPHB2 has been observed in various human cancers, its roles in the development and progression of cancers are still unclear. In the present study, the functional implications of EPHB2 in the acquisition of malignant phenotypes of cSCC cells was investigated. Silencing of EPHB2 in the human cSCC cell line A431 induced epithelial-mesenchymal transition (EMT)-like morphological changes accompanied by a significant upregulation of epithelial-mesenchymal transition-associated genes such as zinc finger E-box binding homeobox 1/2. In addition, silencing of EPHB2 suppressed anchorage-independent cell growth under 3D culture conditions. Consistent with these observations, EPHB2 exhibited higher levels of expression in tumor spheres formed under 3D culture conditions than in cells cultured in adherent form, and the expression pattern of EMT markers indicated that EMT was suppressed in tumor spheres. The results of the present study indicated that EPHB2 serves a pivotal role in promoting the anchorage-independent growth of A431 cells through the suppression of EMT.

A novel liver-specific fluorescent anti-cancer drug delivery system using indocyanine green.

Indocyanine green (ICG) accumulates only in hepatocytes and their malignant counterpart, hepatocellular carcinoma (HCC). We have developed ICG-conjugated anti-cancer drugs and noted their significant accumulation in HCC cells both in vitro and in vivo. ICG-conjugated gemcitabine was less toxic to normal cells and it had superior anti-tumor action compared to gemcitabine alone in a subcutaneous tumor xenograft. ICG conjugation can provide a novel fluorescent drug delivery system for treatment of liver cancer and this system can be used to both diagnose and treat HCC.

EVI1 expression is associated with aggressive behavior in intrahepatic cholangiocarcinoma.

Ecotropic virus integration site 1 protein homolog (EVI1), a well-known oncogenic transcriptional factor of hematopoietic cells, contributes to pancreatic cancer oncogenicity through increased expression of KRAS. Because EVI1 was upregulated in cholangiocarcinoma by referring The Cancer Genome Atlas, we investigated the importance of EVI1 in intrahepatic cholangiocarcinoma (ICC) which has been regarded as a heterogeneous group of cancers. Immunohistochemical analysis results demonstrated that EVI1 was overexpressed in about half of ICC (53/101, 52.5%). Moreover, all intraductal papillary neoplasms of the bile duct cases expressed EVI1 regardless of histological grading and subtypes such as gastric, intestinal, pancreatobiliary, or oncocytic (20/20, 100%). EVI1-positive ICC showed higher frequencies of aggressive pathological indicators such as periductal infiltrative growth (p = 0.022), hilar invasion (p = 0.041), advanced UICC stage (p = 0.026), major vascular invasion (p = 0.026), and perineural invasion (p = 0.007) than EVI1-negative ICC. Patients with EVI1-positive ICC showed worse overall survival and recurrence-free survival in all resected cases and in curative resected cases. Recently, we proposed type 1/2 (large/small duct types) classification of ICC based on mucin productivity and immunophenotypes (S100P, N-cadherin, and NCAM). Type 1 predominantly consisted of EVI1-positive ICC (33/42 cases, 79%), and the frequency was significantly higher than type 2 (18/55 cases, 32.7%) (p < 0.0001). EVI1-positive ICC was likely to express stomach-specific claudin CLDN18 (correlation coefficient r = 0.55373) and mucin MUC5AC (r = 0.42718). EVI1-positive ICC is an aggressive ICC showing both large-duct and/or gastric phenotypes. Consequently, a transcriptional factor EVI1 is associated with aggressive behavior in ICC and can be a therapeutic target molecule, while EVI1 might be a key molecule for the development of intraductal papillary neoplasms of the bile duct.

The impact of apurinic-apyrimidinic endonuclease I on hepatocyte immuno-inflammatory factors and cell apoptosis.

To explore the effect of apurinic-apyrimidinic endonuclease I (APE-1) on hepatocyte immune inflammatory factors and cell apoptosis. The gene expression profiles of peripheral blood of patients with or without immune tolerance after liver transplantation were obtained from the Gene Expression Omnibus (GEO). Differentially expressed genes were analyzed with a program in the R language, and the APE-1 gene was identified as a gene related to immune tolerance of liver transplantation. Four APE-1 shRNA vectors were constructed in parallel and verified as correct using plasmid sequencing, real-time PCR, and Western blotting. An APE-1 overexpression vector was similarly constructed and verified as correct. The STRING website predicted the protein-protein interaction network of APE-1. ELISA was used to detect the effects of APE-1 silencing and overexpression on inflammatory cytokines IL-1ß, IL-10, TNFα, and INF-γ in the control group, APE-1-silenced group, and APE-1 overexpression group. Flow cytometry was used to detect apoptosis in each group. Forty differentially expressed genes related to immune tolerance after liver transplantation were screened, and the highly expressed gene APE-1 was selected. The best APE-1 shRNA_1 vector and APE-1 overexpression vector were obtained. APE-1 is predicted to interact with ANP32A, FEN1, HMGB2, LIG1, MUTYH, NTHL1, OGG1, PCNA, POLB, SET, and other proteins. APE-1 silencing resulted in a significant increase in the expression of the inflammatory factors IL-1ß, IL-10, TNFα, and INF-γin L-02 cells. In contrast, the expression of APE-1 led to a significant decrease in the expression of inflammatory factors. APE-1 silencing significantly increased the rate of apoptosis of L-02 cells, and APE-1 overexpression resulted in a significant decrease in the rate of apoptosis of L-02 cells. In conclusion APE-1 affects the expression of inflammatory factors and apoptosis in L-02 cells, so it may be a key gene in immune tolerance of liver transplantation.

Innovative treatment for hepatocellular carcinoma (HCC).

Indocyanine green (ICG) is not new in the field of liver surgery. Early studies performed in the 1980s and 1990s revealed the value of the ICG clearance test in predicting post-hepatectomy morbidity and mortality. ICG clearance and retention tests are crucial for determining precise liver function before liver surgery and offer several benefits for safe surgery. Whereas ICG is well-known and has long history in medicine, recent progress in infrared light technology over the last decade has highlighted another feature of ICG. For example, ICG fluorescence-guided surgery may change the next generation of liver surgery. In the near future, ICG with near-infrared (NIR) light photodynamic therapy (PDT) is expected to become a new treatment method for hepatocellular carcinoma (HCC). Furthermore, several aspects of the mechanisms of ICG accumulation in HCC cells have been revealed by important basic research studies. New imaging technologies and mechanistic findings keep ICG in the spotlight. In this article, we review three recently described topics of ICG which may contribute to the development of innovative and new treatments method for HCC, fluorescence-guided surgery, mechanism of ICG accumulation in HCC cells, PDT for HCC.

Mapping of new skin tumor susceptibility loci by a phenotype-driven congenic approach.

As cancer susceptibility varies among mouse strains, mouse models are powerful tools for the identification of genes responsible for cancer development. Several cancer susceptibility loci have been mapped by genetic analysis using cancer-resistant and cancer-susceptible mouse strains. However, only a few corresponding genes for these loci have been identified, because most of the cancer susceptibility loci are low-penetrance alleles. We reported previously that wild-derived PWK mice showed no tumor development on treatment with the two-stage skin carcinogenesis protocol [induced by 7.12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)], and that this phenotype is dominant-resistant when crossed with the highly susceptible strain FVB. From the analysis of the F1 backcross generation between PWK and FVB, we have mapped the new significant locus Skts-fp1 on chromosome 4. In the present study, congenic strains were generated with the PWK resistance allele in the FVB background using a phenotype-driven approach, and sought to narrow down the candidate loci and find the responsible gene(s). One of the resistant mice in the N6 generation carried the remaining PWK allele on chromosomes 4, 7 and 11, and an association study using the progeny of this mouse suggested that the locus on chromosome 11 may affect the cancer susceptibility locus on chromosome 7. On the other hand, no skin tumor susceptibility locus was mapped on chromosome 11 as examined in N2 progeny. These findings suggest that there is at least one tumor-resistance gene on chromosome 7, the function of which could be regulated by gene(s) located on chromosome 11.

Host MICA Polymorphism as a Potential Predictive Marker in Response to Chemotherapy for Colorectal Liver Metastases.

BACKGROUND: Understanding the genetic background of a tumor is important to better stratify patient prognosis and select optimal treatment. For colorectal liver metastases (CLM), however, clinically available biomarkers remain limited. METHODS: After a comprehensive sequencing of 578 cancer-related genes in 10 patients exhibiting very good/poor responses to chemotherapy, the A5.1 variant of the MICA gene was selected as a potential biomarker for CLM. The clinical relevance of MICA A5.1 was then investigated in 58 patients who underwent CLM resection after chemotherapy. RESULTS: The A5.1 variant was observed in 16 (27.6%) patients examined using direct DNA sequencing, and a very high concordance rate (56/58, 96.6%) for the MICA variant was confirmed between tumor tissues and normal liver parenchyma. A multivariate analysis of 38 patients with no history of treatment with anti-EGFR antibodies confirmed that MICA A5.1 was significantly correlated with an optimal CT morphologic response (OR 11.67; 95% CI 2.08-65.60; p = 0.005) and tended to be correlated with a tumor viability of < 20% after chemotherapy (OR 5.91; 95% CI 0.97-36.02; p = 0.054). MICA A5.1 was also associated with a decreased risk of progression after CLM resection. CONCLUSION: The MICA A5.1 polymorphism was associated with a better CT morphologic response to chemotherapy and a reduced risk of relapse after CLM resection. Given the high concordance rate in MICA variants between normal liver tissue and CLM, the genetic background of the host could be a new biomarker for CLM.

Shufeng Jiedu Capsule and its active ingredients induce apoptosis, inhibit migration and invasion, and enhances doxorubicin therapeutic efficacy in hepatocellular carcinoma.

BACKGROUND: Shufeng Jiedu Capsule (SFJDC), a traditional Chinese medicine, has been used widely as antiviral, antibacterial, antitumor, and anti-inflammatory drugs. Previous studies indicated that some active ingredients of Shufeng Jiedu Capsule, such as resveratrol and quercetin, could suppress hepatocellular carcinoma (HCC) cells through various signaling pathways. However, anti-HCC activity of SFJDC as a complementary medicine remains unexplored. Here, we use a combination of Shufeng Jiedu Capsule and doxorubicin to treat HCC cells and investigated the effects and mechanisms of SFJDC and its ingredientsin vitro. METHODS: In this study, two HCC cell lines, HepG2 and HepG2.2.15, were employed and all cells were separated into seven groups: doxorubicin group, SFJDC group, combination of doxorubicin and SFJDC group, resveratrol group, quercetin group, resveratrol and quercetin group, and control group. Through this research, the cellular functional experiments, such as MTT assay, Hoechst 33,258 staining, would healing assay, and transwell assay, were took to observe the effects of those agents on proliferation, apoptosis, migration and invasion of cells. Then, apoptosis and invasion related genes and proteins were detected by real-time PCR and western blot to illuminate the signaling pathways. RESULTS: The combination group induced more significant apoptosis and inhibition of migration and invasion by affecting proteins and mRNA of apoptosis, migration, and invasion related elements, such as Bcl-2, Bax, mTOR, and NF-?B. Furthermore, the research suggested SFJDC, as a mixture of a number of ingredients, had stronger activities than particular component or simple mixture of a few components. CONCLUSIONS: SFJDC and its active ingredients could play a role as complementary medicine to increase antitumor effect of doxorubicin by targeting mitochondrial, Akt/mTOR, and NF-?B signaling pathways.

Near-infrared photothermal/photodynamic therapy with indocyanine green induces apoptosis of hepatocellular carcinoma cells through oxidative stress.

Indocyanine green (ICG) is a photothermal agent, photosensitizer, and fluorescence imaging probe which shows specific accumulation in hepatocellular carcinoma (HCC) cells. We recently developed a photodynamic therapy (PDT) using ICG and near-infrared (NIR) laser as a new anti-cancer treatment for HCC. However, the molecular mechanism underlying this effect needs to be elucidated. HuH-7 cells, a well-differentiated human HCC cell line, were transplanted subcutaneously into BALB/c-nu/nu mice for in vivo experiment. ICG was administered 24 h before NIR irradiation. The irradiation was performed at three tumor locations by 823-nm NIR laser on days 1 and 7. The temperature of HuH-7 xenografts increased to 48.5 °C 3 minutes after ICG-NIR irradiation start. Reactive oxygen species (ROS) production was detected after ICG-NIR irradiation both in vitro and in vivo. There was certain anti-tumor effect and ROS production even under cooling conditions. Repeated NIR irradiation increased the cell toxicity of ICG-NIR therapy; the mean tumor volume on day 9 was significantly smaller after ICG-NIR irradiation compared to tumor without irradiation (87 mm3 vs. 1332 mm3; p = 0.01) in HCC mice xenografts model. ICG-NIR therapy induced apoptosis in HCC cells via a photothermal effect and oxidative stress. Repeated ICG-NIR irradiation enhanced the anti-tumor effect.