ICBP90, an E2F-1 target, recruits HDAC1 and binds to methyl-CpG through its SRA domain

ICBP90, inverted CCAAT box-binding protein of 90 kDa, has been reported as a regulator of topoisomerase IIalpha expression. We present evidence here that ICBP90 binds to methyl-CpG when at least one symmetrically methylated-CpG dinucleotides is presented as its recognition sequence. A SET and RING finger-associated (SRA) domain accounts for the high binding affinity of ICBP90 for methyl-CpG dinucleotides. This protein constitutes a complex with HDAC1 also via its SRA domain, and bound to methylated promoter regions of various tumor suppressor genes, including p16INK4Aand p14ARF, in cancer cells. It has been reported that expression of ICBP90 was upregulated by E2F-1, and we confirmed that the upregulation was caused by binding of E2F-1 to the intron1 of ICBP90, which contains two E2F-1-binding motifs. Our data also revealed accumulation of ICBP90 in breast-cancer cells, where it might suppress expression of tumor suppressor genes through deacetylation of histones after recruitment of HDAC1. The data reported here suggest that ICBP90 is involved in cell proliferation by way of methylation-mediated regulation of certain genes.

Enhanced SMYD3 expression is essential for the growth of breast cancer cells

We previously reported that upregulation of SMYD3, a histone H3 lysine-4-specific methyltransferase, plays a key role in the proliferation of colorectal carcinoma (CRC) and hepatocellular carcinoma (HCC). In the present study, we reveal that SMYD3 expression is also elevated in the great majority of breast cancer tissues. Similarly to CRC and HCC, silencing of SMYD3 by small interfering RNA to this gene resulted in the inhibited growth of breast cancer cells, suggesting that increased SMYD3 expression is also essential for the proliferation of breast cancer cells. Moreover, we show here that SMYD3 could promote breast carcinogenesis by directly regulating expression of the proto-oncogene WNT10B. These data imply that augmented SMYD3 expression plays a crucial role in breast carcinogenesis, and that inhibition of SMYD3 should be a novel therapeutic strategy for treatment of breast cancer.

PDZ-binding kinase/T-LAK cell-originated protein kinase, a putative cancer/testis antigen with an oncogenic activity in breast cancer

Breast cancer is one of the most common cancers among women. To discover molecular targets that are applicable for development of novel breast cancer therapy, we previously did genome-wide expression profile analysis of 81 breast cancers and found dozens of genes that were highly and commonly up-regulated in breast cancer cells. Among them, we here focused on one gene that encodes PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK), including a kinase domain. Northern blot analyses using mRNAs of normal human organs, breast cancer tissues, and cancer cell lines indicated this molecule to be a novel cancer/testis antigen. Reduction of PBK/TOPK expression by small interfering RNA resulted in significant suppression of cell growth probably due to dysfunction in the cytokinetic process. Immunocytochemical analysis with anti-PBK/TOPK antibody implicated a critical role of PBK/TOPK in an early step of mitosis. PBK/TOPK could phosphorylate histone H3 at Ser10 in vitro and in vivo, and mediated its growth-promoting effect through histone H3 modification. Because PBK/TOPK is the cancer/testis antigen and its kinase function is likely to be related to its oncogenic activity, we suggest PBK/TOPK to be a promising molecular target for breast cancer therapy.

Involvement of maternal embryonic leucine zipper kinase (MELK) in mammary carcinogenesis through interaction with Bcl-G, a pro-apoptotic member of the Bcl-2 family

Introduction

Cancer therapies directed at specific molecular targets in signaling pathways of cancer cells, such as tamoxifen, aromatase inhibitors and trastuzumab, have proven useful for treatment of advanced breast cancers. However, increased risk of endometrial cancer with long-term tamoxifen administration and of bone fracture due to osteoporosis in postmenopausal women undergoing aromatase inhibitor therapy are recognized side effects. These side effects as well as drug resistance make it necessary to search for novel molecular targets for drugs on the basis of well-characterized mechanisms of action.

Methods

Using accurate genome-wide expression profiles of breast cancers, we found maternal embryonic leucine-zipper kinase (MELK) to be significantly overexpressed in the great majority of breast cancer cells. To assess whether MELK has a role in mammary carcinogenesis, we knocked down the expression of endogenous MELK in breast cancer cell lines using mammalian vector-based RNA interference. Furthermore, we identified a long isoform of Bcl-G (Bcl-G_L), a pro-apoptotic member of the Bcl-2 family, as a possible substrate for MELK by pull-down assay with recombinant wild-type and kinase-dead MELK. Finally, we performed TUNEL assays and FACS analysis, measuring proportions of apoptotic cells, to investigate whether MELK is involved in the apoptosis cascade through the Bcl-G_L-related pathway.

Results

Northern blot analyses on multiple human tissues and cancer cell lines demonstrated that MELK was overexpressed at a significantly high level in a great majority of breast cancers and cell lines, but was not expressed in normal vital organs (heart, liver, lung and kidney). Suppression of MELK expression by small interfering RNA significantly inhibited growth of human breast cancer cells. We also found that MELK physically interacted with Bcl-G_L through its amino-terminal region. Immunocomplex kinase assay showed that Bcl-G_L was specifically phosphorylated by MELK in vitro. TUNEL assays and FACS analysis revealed that overexpression of wild-type MELK suppressed Bcl-G_L-induced apoptosis, while that of D150A-MELK did not.

Conclusion

Our findings suggest that the kinase activity of MELK is likely to affect mammary carcinogenesis through inhibition of the pro-apoptotic function of Bcl-G_L. The kinase activity of MELK could be a promising molecular target for development of therapy for patients with breast cancers.

Critical roles of mucin 1 glycosylation by transactivated polypeptide N-acetylgalactosaminyltransferase 6 in mammary carcinogenesis

The structure of O-glycosylated proteins is altered in breast cancer cells, but the mechanisms of such an aberrant modification have been largely unknown. We here report critical roles of a novel druggable target, polypeptide N-acetylgalactosaminyltransferase 6 (GALNT6), which is upregulated in a great majority of breast cancers and encodes a glycosyltransferase responsible for initiating mucin-type O-glycosylation. Knockdown of GALNT6 by small interfering RNA significantly enhanced cell adhesion function and suppressed the growth of breast cancer cells. Western blot and immunostaining analyses indicated that wild-type GALNT6 protein could glycosylate and stabilize an oncoprotein mucin 1 (MUC1), which was upregulated with GALNT6 in breast cancer specimens. Furthermore, knockdown of GALNT6 or MUC1 led to similar morphologic changes of cancer cells accompanied by the increase of cell adhesion molecules beta-catenin and E-cadherin. Our findings implied that overexpression of GALNT6 might contribute to mammary carcinogenesis through aberrant glycosylation and stabilization of MUC1 and that screening of GALNT6 inhibitors would be valuable for the development of novel therapeutic modalities against breast cancer.

Ubiquitination and downregulation of BRCA1 by ubiquitin-conjugating enzyme E2T overexpression in human breast cancer cells

Breast cancer is generated through a multistep genetic and epigenetic process including activations of oncogenes and inactivations of tumor suppressor genes. Here, we report a critical role of ubiquitin-conjugating enzyme E2T (UBE2T), an E2 ubiquitin-conjugating enzyme, in mammary carcinogenesis. Immunocytochemical staining and in vitro binding assay revealed that UBE2T interacted and colocalized with the BRCA1/BRCA1-associated RING domain protein (BARD1) complex. Knocking down of UBE2T expression with small interfering RNA drastically suppressed the growth of breast cancer cells. Interestingly, in vivo ubiquitination assay indicated BRCA1 to be polyubiquitinated by incubation with wild-type UBE2T protein, but not with C86A-UBE2T protein, an E2 activity-dead mutant, in which the 86th residue of cysteine was replaced with alanine. Furthermore, knocking down of UBE2T protein induced upregulation of BRCA1 protein in breast cancer cells, whereas its overexpression caused the decrease of the BRCA1 protein. Our data imply a critical role of UBE2T in development and/or progression of breast cancer through the interaction with and the regulation of the BRCA1/BARD1 complex.

Elevated expression of protein regulator of cytokinesis 1, involved in the growth of breast cancer cells

To elucidate molecular mechanisms of mammary carcinogenesis and discover novel therapeutic targets for breast cancer, we previously carried out a genome-wide expression profile analysis of 81 breast cancer cases by means of a combination of cDNA microarray and laser microbeam microdissection. Among the upregulated genes, we focused on the functional significance of protein regulator of cytokinesis 1 (PRC1) in the development of breast cancer. Western blot analysis using breast cancer cell lines revealed a significant increase in endogenous PRC1 levels in G(2)/M phase. Treatment of breast cancer cells with small interfering RNA against PRC1 effectively suppressed its expression and inhibited the growth of breast cancer cell lines T47D and HBC5. Furthermore, we found an interaction between PRC1 and kinesin family member 2C/mitotic centromere-associated kinesin (KIF2C/MCAK) by coimmunoprecipitation and immunoblotting using COS-7 cells, in which these molecules were introduced exogenously. These findings suggest the involvement of a PRC1-KIF2C/MCAK complex in breast tumorigenesis, and this complex should be a promising target for the development of novel treatments for breast cancer.

Involvement of elevated expression of multiple cell-cycle regulator, DTL/RAMP (denticleless/RA-regulated nuclear matrix associated protein), in the growth of breast cancer cells

To investigate the detailed molecular mechanism of mammary carcinogenesis and discover novel therapeutic targets, we previously analysed gene expression profiles of breast cancers. We here report characterization of a significant role of DTL/RAMP (denticleless/RA-regulated nuclear matrix associated protein) in mammary carcinogenesis. Semiquantitative RT-PCR and northern blot analyses confirmed upregulation of DTL/RAMP in the majority of breast cancer cases and all of breast cancer cell lines examined. Immunocytochemical and western blot analyses using anti-DTL/RAMP polyclonal antibody revealed cell-cycle-dependent localization of endogenous DTL/RAMP protein in breast cancer cells; nuclear localization was observed in cells at interphase and the protein was concentrated at the contractile ring in cytokinesis process. The expression level of DTL/RAMP protein became highest at G(1)/S phases, whereas its phosphorylation level was enhanced during mitotic phase. Treatment of breast cancer cells, T47D and HBC4, with small-interfering RNAs against DTL/RAMP effectively suppressed its expression and caused accumulation of G(2)/M cells, resulting in growth inhibition of cancer cells. We further demonstrate the in vitro phosphorylation of DTL/RAMP through an interaction with the mitotic kinase, Aurora kinase-B (AURKB). Interestingly, depletion of AURKB expression with siRNA in breast cancer cells reduced the phosphorylation of DTL/RAMP and decreased the stability of DTL/RAMP protein. These findings imply important roles of DTL/RAMP in growth of breast cancer cells and suggest that DTL/RAMP might be a promising molecular target for treatment of breast cancer.

Optimizing antiemetic treatment for chemotherapy-induced nausea and vomiting in Japan: Update summary of the 2015 Japan Society of Clinical Oncology Clinical Practice Guidelines for Antiemesis

Patients with cancer should appropriately receive antiemetic therapies against chemotherapy-induced nausea and vomiting (CINV). Antiemetic guidelines play an important role in managing CINV. Accordingly, the first Japanese antiemetic guideline published in 2010 by the Japan Society of Clinical Oncology (JSCO) has considerably aided Japanese medical staff in providing antiemetic therapies across chemotherapy clinics. With the yearly advancements in antiemetic therapies, the Japanese antiemetic guidelines require revisions according to published evidence regarding antiemetic management worldwide. A revised version of the first antiemetic guideline that considered several upcoming evidences had been published online in 2014 (version 1.2), in which several updated descriptions were included. The 2015 JSCO clinical practice guideline for antiemesis (version 2.0) (in Japanese) has addressed clinical antiemetic concerns and includes four major revisions regarding (1) changes in emetogenic risk categorization for anti-cancer agents, (2) olanzapine usage as an antiemetic drug, (3) the steroid-sparing method, and (4) adverse drug reactions of antiemetic agents. We herein present an English update summary for the 2015 JSCO clinical practice guideline for antiemesis (version 2.0).

Critical roles of T-LAK cell-originated protein kinase in cytokinesis

We previously reported up-regulation of T-LAK cell-originated protein kinase (TOPK), a novel mitotic kinase, in the great majority of breast cancers. Here we report its critical roles in mitosis, especially in cytokinesis. We found that protein phosphatase 1 alpha (PP1alpha) inactivation by cyclin-dependent kinase 1 (CDK1)/cyclin B1 caused enhancement of autophosphorylation of TOPK and resulted in its activation at an early stage of mitosis. Then TOPK interacted with and phosphorylated p97, a member of the AAA+ family of ATPase proteins, through an interaction with p47 protein as an adaptor protein. Interestingly, knockdown of TOPK or p97 in breast cancer cells caused the mitotic failures in the abscission process. This mitotic failure could be rescued by additional exogenous introduction of wild-type TOPK protein, but not by that of its kinase-dead form. Our findings suggest that TOPK is indispensable for cancer cell cytokinesis throughout phosphorylation on p97.

Involvement of kinesin family member 2C/mitotic centromere-associated kinesin overexpression in mammary carcinogenesis

To elucidate the molecular mechanisms of mammary carcinogenesis and discover novel therapeutic targets for breast cancer, we previously carried out genome-wide expression profile analysis of 81 breast cancer cases by means of cDNA microarray coupled with laser microbeam microdissection of cancer cells. Among the dozens of transactivated genes, in the present study we focused on the functional significance of kinesin family member 2C (KIF2C)/mitotic centromere-associated kinesin (MCAK) in the growth of breast cancer cells. Northern blot and immunohistochemical analyses confirmed KIF2C/MCAK overexpression in breast cancer cells, and showed that it is expressed at undetectable levels in normal human tissues except the testis, suggesting KIF2C/MCAK to be a cancer-testis antigen. Western blot analysis using breast cancer cell lines revealed a significant increase in the endogenous KIF2C/MCAK protein level and its phosphorylation in G(2)/M phase. Treatment of breast cancer cells with small interfering RNA against KIF2C/MCAK effectively suppressed KIF2C/MCAK expression and inhibited the growth of the breast cancer cell lines T47D and HBC5. In addition, we found that KIF2C/MCAK expression was significantly suppressed by ectopic introduction of p53. These findings suggest that overexpression of KIF2C/MCAK might be involved in breast carcinogenesis and is a promising therapeutic target for breast cancers.

Propensity score analysis demonstrated the prognostic advantage of anatomical liver resection in hepatocellular carcinoma

AIM: To compare the prognoses of hepatocellular carcinoma (HCC) patients that underwent anatomic liver resection (AR) or non-anatomic liver resection (NAR) using propensity score-matched populations.

METHODS: Between January 2002 and December 2010, 268 consecutive HCC patients, including 110 and 158 patients that underwent AR and NAR, respectively, were retrospectively enrolled in this study. Forty-four patients from each group were selected and matched using logistic multivariate analysis followed by propensity score analysis.

RESULTS: In the whole analysis set, the histological background of the liver, liver function, and tumor marker levels differed significantly among the groups. Although the overall survival (OS) and recurrence-free survival rates of the two groups did not differ significantly in the whole analysis set, the OS of the AR group was significantly longer than that of the NAR group after propensity matching (76.2 ± 6.3 mo vs 58.9 ± 6.3 mo; P = 0.0039). Although AR (HR = 0.456, P = 0.039) was found to be a prognostic factor in the univariate analysis, only vascular invasion (HR = 0.228, P = 0.002) and the hepatocyte growth factor level (HR = 52.366, P = 0.035) were subsequently found to be independent prognostic factors.

CONCLUSION: AR conveys a survival advantage over NAR in specific subpopulations of HCC patients with tumors of less than 5 cm in diameter, single tumor, and good liver function.

Activation of an estrogen/estrogen receptor signaling by BIG3 through its inhibitory effect on nuclear transport of PHB2/REA in breast cancer

Breast cancer is known to be a hormone-dependent disease, and estrogens through an interaction with estrogen receptor (ER) enhance the proliferative and metastatic activity of breast tumor cells. Here we show a critical role of transactivation of BIG3, brefeldin A-inhibited guanine nucleotide-exchange protein 3, in activation of the estrogen/ER signaling in breast cancer cells. Knocking-down of BIG3 expression with small-interfering RNA (siRNA) drastically suppressed the growth of breast cancer cells. Subsequent coimmunoprecipitation and immunoblotting assays revealed an interaction of BIG3 with prohibitin 2/repressor of estrogen receptor activity (PHB2/REA). When BIG3 was absent, stimulation of estradiol caused the translocation of PHB2/REA to the nucleus, enhanced the interaction of PHB2/REA and ERalpha, and resulted in suppression of the ERalpha transcriptional activity. On the other hand, when BIG3 was present, BIG3 trapped PHB2/REA in the cytoplasm and inhibited its nuclear translocation, and caused enhancement of ERalpha transcriptional activity. Our results imply that BIG3 overexpression is one of the important mechanisms causing the activation of the estrogen/ERalpha signaling pathway in the hormone-related growth of breast cancer cells.

Comprehensive review of post-liver resection surgical complications and a new universal classification and grading system

Liver resection is the gold standard treatment for certain liver tumors such as hepatocellular carcinoma and metastatic liver tumors. Some patients with such tumors already have reduced liver function due to chronic hepatitis, liver cirrhosis, or chemotherapy-associated steatohepatitis before surgery. Therefore, complications due to poor liver function are inevitable after liver resection. Although the mortality rate of liver resection has been reduced to a few percent in recent case series, its overall morbidity rate is reported to range from 4.1% to 47.7%. The large degree of variation in the post-liver resection morbidity rates reported in previous studies might be due to the lack of consensus regarding the definitions and classification of post-liver resection complications. The Clavien-Dindo (CD) classification of post-operative complications is widely accepted internationally. However, it is hard to apply to some major post-liver resection complications because the consensus definitions and grading systems for post-hepatectomy liver failure and bile leakage established by the International Study Group of Liver Surgery are incompatible with the CD classification. Therefore, a unified classification of post-liver resection complications has to be established to allow comparisons between academic reports.

Japanese Society of Clinical Oncology clinical practice guidelines 2010 for antiemesis in oncology: executive summary

The purpose of this article is to disseminate the standard of antiemetic therapy for Japanese clinical oncologists. On the basis of the Appraisal of Guidelines for Research and Evaluation II instrument, which reflects evidence-based clinical practice guidelines, a working group of the Japanese Society of Clinical Oncology (JSCO) reviewed clinical practice guidelines for antiemesis and performed a systematic review of evidence-based domestic practice guidelines for antiemetic therapy in Japan. In addition, because health-insurance systems in Japan are different from those in other countries, a consensus was reached regarding standard treatments for chemotherapy that induce nausea and vomiting. Current evidence was collected by use of MEDLINE, from materials from meetings of the American Society of Clinical Oncology National Comprehensive Cancer Network, and from European Society of Medical Oncology/Multinational Association of Supportive Care in Cancer guidelines for antiemesis. Initially, 21 clinical questions (CQ) were selected on the basis of CQs from other guidelines. Patients treated with highly emetic agents should receive a serotonin (5-hydroxytryptamine; 5HT3) receptor antagonist, dexamethasone, and a neurokinin 1 receptor antagonist. For patients with moderate emetic risk, 5HT3 receptor antagonists and dexamethasone were recommended, whereas for those receiving chemotherapy with low emetic risk dexamethasone only is recommended. Patients receiving high-emetic-risk radiation therapy should also receive a 5HT3 receptor antagonist. In this paper the 2010 JSCO clinical practice guidelines for antiemesis are presented in English; they reveal high concordance of Japanese medical circumstances with other antiemetic guidelines that are similarly based on evidence.

Prognostic roles of preoperative α-fetoprotein and des-γ-carboxy prothrombin in hepatocellular carcinoma patients

AIM: To clarify the utility of using des-γ-carboxy prothrombin (DCP) and α-fetoprotein (AFP) levels to predict the prognosis of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) and the hepatitis C virus (HCV) infections.

METHODS: A total of 205 patients with HCC (105 patients with HBV infection 100 patients with HCV infection) who underwent primary hepatectomy between January 2004 and May 2012 were enrolled retrospectively. Preoperative AFP and DCP levels were used to create interactive dot diagrams to predict recurrence within 2 years after hepatectomy, and cutoff levels were calculated. Patients in the HBV and HCV groups were classified into three groups: a group with low AFP and DCP levels (LL group), a group in which one of the two parameters was high and the other was low (HL group), and a group with high AFP and DCP levels (HH group). Liver function parameters, the postoperative recurrence-free survival rate, and postoperative overall survival were compared between groups. The survival curves were compared by log-rank test using the Kaplan-Meier method. Multivariate analysis using a Cox forward stepwise logistic regression model was conducted for a prognosis.

RESULTS: The preoperative AFP cutoff levels for recurrence within 2 years after hepatectomy in the HBV and HCV groups were 529.8 ng/mL and 60 mAU/mL, respectively; for preoperative DCP levels, the cutoff levels were 21.0 ng/mL in the HBV group and 67 mAU/mL in the HCV group. The HBV group was significantly different from the other groups in terms of vascular invasion, major hepatectomy, volume of intraoperative blood loss, and surgical duration. Significant differences were found between the LL group, the HL group, and the HH group in terms of both mean disease-free survival time (MDFST) and mean overall survival time (MOST): 64.81 ± 7.47 vs 36.63 ± 7.62 vs 18.98 ± 6.17 mo (P = 0.001) and 85.30 ± 6.55 vs 59.44 ± 7.87 vs 46.57 ± 11.20 mo (P = 0.018). In contrast, the HCV group exhibited a significant difference in tumor size, vascular invasion, volume of intraoperative blood loss, and surgical duration; however, no significant difference was observed between the three groups in liver function parameters except for albumin levels. In the LL group, the HL group, and the HH group, the MDFST was 50.09 ± 5.90, 31.01 ± 7.21, and 14.81 ± 3.08 mo (log-rank test, P < 0.001), respectively, and the MOST was 79.45 ± 8.30, 58.82 ± 7.56, and 32.87 ± 6.31 mo (log-rank test, P < 0.001), respectively.

CONCLUSION: In the HBV group, the prognosis was poor when either AFP or DCP levels were high. In the HCV group, the prognosis was good when either or both levels were low; however, the prognosis was poor when both levels were high. High levels of both AFP and DCP were an independent risk factor associated with tumor recurrence in the HBV and HCV groups. The relationship between tumor marker levels and prognosis was characteristic to the type of viral hepatitis.

ST6GALNAC1 plays important roles in enhancing cancer stem phenotypes of colorectal cancer via the Akt pathway

Colorectal cancer (CRC) is a mortal disease due to treatment resistance, recurrence and distant metastasis. Emerging evidence has revealed that a small sub-population of cancer cells termed cancer stem cells (CSCs)/ cancer-initiating cells (CICs) is endowed with high levels of tumor-initiating ability, self-renewal ability and differentiation ability and is responsible for treatment resistance, recurrence and distant metastasis. Eradication of CSCs/CICs is essential to improve current treatments. However, the molecular mechanisms by which CSCs/CICs are maintained are still elusive. In this study, we aimed to determine the molecular mechanisms by which colorectal (CR)-CSCs/CICs in are maintained human primary CRC cells. CR-CSCs/CICs were isolated by sphere-culture and the ALDEFLUOR assay, and transcriptome analysis revealed that the gene ST6 N-Acetylgalactosaminide Alpha-2,6-Sialyltransferase 1 (ST6GALNAC1) was expressed at high levels in CR-CSCs/CICs. Overexpression of ST6GALNAC1 enhanced the expression of sialyl-Tn (STn) antigen, which is carried by the CSC marker CD44, and increased the sphere-forming ability and resistance to a chemotherapeutic reagent. The opposite phenomena were observed by gene knockdown using siRNA. Furthermore, the Akt pathway was activated in ST6GANAC1-overexpressed cells, and activation of the pathway was cancelled by gene knockdown of galectin-3. The results indicate that ST6GALNAC1 has a role in the maintenance of CR-CSCs/CICs by activating the Akt pathway in cooperation with galectin-3 and that ST6GalNAC1 (or STn antigen) might be a reasonable molecule for CSC/CIC-targeting therapy.

Involvement of G-patch domain containing 2 overexpression in breast carcinogenesis

Through analysis of the detailed genome-wide gene expression profiles of 81 breast tumors, we identified a novel gene, G-patch domain containing 2 (GPATCH2), that was overexpressed in the great majority of breast cancer cases. Treatment of breast cancer cells MCF-7 and T47D with siRNA against GPATCH2 effectively suppressed its expression, and resulted in the growth suppression of cancer cells, suggesting its essential role in breast cancer cell growth. We found an interaction of GPATCH2 protein with hPrp43, an RNA-dependent ATPase. Their interaction could significantly enhance the ATPase activity of hPrp43 and induce a growth-promoting effect on mammalian cells. Because northern blot analyses of normal human organs implied GPATCH2 to be a novel cancer/testis antigen, targeting GPATCH2 or inhibition of the interaction between GPATCH2 and hPrp43 could be a promising novel therapeutic strategy of breast cancer.

Efficacy of indocyanine green fluorescence angiography in preventing anastomotic leakage after laparoscopic colorectal cancer surgery

PURPOSE

Some recent studies have suggested that fluorescence angiography with indocyanine green (ICG) might be useful for preventing anastomotic leakage (AL) after laparoscopic colorectal surgery. However, its efficacy has not been proven. We evaluated whether intraoperative ICG fluorescence angiography could decrease the AL rate with laparoscopic colorectal cancer surgery.

METHODS

This retrospective study included patients with colorectal cancer who underwent laparoscopic surgery at our institution between March 2014 and December 2018. Patients were divided into two groups: with or without ICG fluorescence angiography. The primary outcome was the rate of AL.

RESULTS

A total of 488 patients were included: 223 patients in the ICG group and 265 patients in the no-ICG group. In the ICG group, the transection line was changed to a more proximal location in seven patients (3.1%), including one patient with transverse colon surgery and six with rectal surgery. None of these seven patients developed AL. There were 18 ALs (3.7%) overall. The AL rate was 1.8% in the ICG group and 5.3% in the no-ICG group. For colon cancer, there were no significant differences in the AL rate between the groups (p = 0.278). In rectal cancer, the AL rate was significantly lower in the ICG group than in the no-ICG group (3.5% vs. 10.5%, p = 0.041). After propensity score matching, the AL rate was also significantly lower in the ICG group for rectal cancer (p = 0.044).

CONCLUSION

ICG fluorescence angiography can potentially reduce the AL rate with laparoscopic rectal cancer surgery.

Single nucleotide polymorphism in ABCG2 is associated with irinotecan-induced severe myelosuppression

Irinotecan is an anti-neoplastic agent that is widely used for treating colorectal and lung cancers, but often causes toxicities such as severe myelosuppression and diarrhea. In this study, we performed a two-stage case-control association study for irinotecan-induced severe myelosuppression (grades 3 and 4). In the first stage, 23 patients who developed severe myelosuppression and 58 patients who did not develop any toxicity were examined for 170 single nucleotide polymorphisms (SNPs) in 14 genes involved in the metabolism and transport of irinotecan. A total of five SNPs were identified to show the possible association with severe myelosuppression (P(Fisher)<0.01) and were further examined in 7 cases and 20 controls in the second stage of the study. An intronic SNP, rs2622604, in ABCG2 showed P(Fisher)=0.0419 in the second stage and indicated a significant association with severe myelosuppression in the combined study (P(Fisher)=0.000237; P(Corrected)=0.036). Although only limited subjects were investigated, our results suggested that a genetic polymorphism in ABCG2 might alter the transport activity for the drug and elevate the systemic circulation level of irinotecan, leading to severe myelosuppression.

Clinical feasibility of laparoscopic lateral pelvic lymph node dissection following total mesorectal excision for advanced rectal cancer

PURPOSE

To evaluate the technical feasibility, safety and oncological outcomes of laparoscopic lateral pelvic lymph node dissection in patients with advanced low rectal cancer.

METHODS

Laparoscopic lateral pelvic lymph node dissection was performed in 18 patients from November 2009 to September 2012. The data regarding the patient demographics, surgical outcomes and short-term oncological outcomes were analyzed.

RESULTS

In all 18 patients, the procedures were completed without conversion to open surgery. The mean length of the operation was 603.7 min (473-746 min). The mean number of harvested lateral pelvic lymph nodes was 16.9 (7-27), and five patients (27.8 %) had lymph node metastases. The postoperative mortality and morbidity rates were 0 and 16.7 %, respectively. Three patients developed Grade 2 urinary retention. No local recurrence had developed after a mean follow-up period of 23.6 months.

CONCLUSION

Laparoscopic lateral pelvic lymph node dissection is technically feasible, safe and oncologically acceptable within the limitations of the short-term follow-up period.

Timing of indocyanine green injection prior to laparoscopic colorectal surgery for tumor localization: a prospective case series

Background

Accurate identification of tumor sites during laparoscopic colorectal surgery helps to optimize oncological clearance. We aimed to assess the timing of the local injection preoperatively and clarify the usefulness and limitation of tumor site marking using indocyanine green (ICG) fluorescence imaging.

Methods

Consecutive patients who underwent primary colorectal cancer surgery from September 2017 to January 2019 were included. Preoperatively, lower endoscopy was used to inject the ICG solution into the submucosal layer near the tumor. During laparoscopic surgery, ICG fluorescence marking as the tumor site marking was detected using a laparoscopic near-infrared camera system. The detection rate and factors associated with successful intraoperative ICG fluorescence visualization including the interval between local injection and surgery were evaluated.

Results

One hundred sixty-five patients were enrolled. Using the laparoscopic near-infrared system, the intraoperative detection rates of ICG marking were 100% for ICG injection within 6 days preoperatively, 60% for injection between 7 and 9 days preoperatively, and 0% for injection earlier than 10 days preoperatively. There were no complications associated with ICG marking. Additionally, this method did not disturb the progress of the surgical procedure because injected ICG in the submucosal layer did not cause any tissue inflammation, and if ICG spilled into the serosa, it was invisible by white light.

Conclusion

Advantages of ICG fluorescence tumor site marking were high visibility of infrared imaging during laparoscopic colorectal surgery and minimal adverse events of surgery. One of the most important findings regarding practical use was a rapid decrease in fluorescence marking visibility if one week passed from the time of ICG local injection.

Upregulation of adipocyte enhancer-binding protein 1 in endothelial cells promotes tumor angiogenesis in colorectal cancer

Tumor angiogenesis is an important therapeutic target in colorectal cancer (CRC). We aimed to identify novel genes associated with angiogenesis in CRC. Using RNA sequencing analysis in normal and tumor endothelial cells (TECs) isolated from primary CRC tissues, we detected frequent upregulation of adipocyte enhancer‐binding protein 1 (AEBP1) in TECs. Immunohistochemical analysis revealed that AEBP1 is upregulated in TECs and stromal cells in CRC tissues. Quantitative RT‐PCR analysis showed that there is little or no AEBP1 expression in CRC cell lines, but that AEBP1 is well expressed in vascular endothelial cells. Levels of AEBP1 expression in Human umbilical vein endothelial cells (HUVECs) were upregulated by tumor conditioned medium derived from CRC cells or by direct coculture with CRC cells. Knockdown of AEBP1 suppressed proliferation, migration, and in vitro tube formation by HUVECs. In xenograft experiments, AEBP1 knockdown suppressed tumorigenesis and microvessel formation. Depletion of AEBP1 in HUVECs downregulated a series of genes associated with angiogenesis or endothelial function, including aquaporin 1 (AQP1) and periostin (POSTN), suggesting that AEBP1 might promote angiogenesis through regulation of those genes. These results suggest that upregulation of AEBP1 contributes to tumor angiogenesis in CRC, which makes AEBP1 a potentially useful therapeutic target.