Depletion of proteasome subunit PSMD1 induces cancer cell death via protein ubiquitination and DNA damage, irrespective of p53 status

Hepatocellular carcinoma (HCC) is characterized by high incidence and fatality rates worldwide. In our exploration of prognostic factors in HCC, the 26s proteasome subunit, non-ATPase 1 (PSMD1) protein emerged as a significant contributor, demonstrating its potential as a therapeutic target in this aggressive cancer. PSMD1 is a subunit of the 19S regulatory particle in the 26S proteasome complex; the 19S particle controls the deubiquitination of ubiquitinated proteins, which are then degraded by the proteolytic activity of the complex. Proteasome-targeting in cancer therapy has received significant attention because of its practical application as an established anticancer agent. We investigated whether PSMD1 plays a critical role in cancer owing to its prognostic significance. PSMD1 depletion induced cell cycle arrest in G2/M phase, DNA damage and apoptosis of cancer cells, irrespective of the p53 status. PSMD1 depletion-mediated cell death was accompanied by an increase in overall protein ubiquitination. These phenotypes occurred exclusively in cancer cells, with no effects observed in normal cells. These findings indicate that PSMD1 depletion-mediated ubiquitination of cellular proteins induces cell cycle arrest and eventual death in cancer cells, emphasizing PSMD1 as a potential therapeutic target in HCC.

A Cell-Penetrant Peptide Disrupting the Transcription Factor CP2c Complexes Induces Cancer-Specific Synthetic Lethality

Despite advances in precision oncology, cancer remains a global public health issue. In this report, proof-of-principle evidence is presented that a cell-penetrable peptide (ACP52C) dissociates transcription factor CP2c complexes and induces apoptosis in most CP2c oncogene-addicted cancer cells through transcription activity-independent mechanisms. CP2cs dissociated from complexes directly interact with and degrade YY1, leading to apoptosis via the MDM2-p53 pathway. The liberated CP2cs also inhibit TDP2, causing intrinsic genome-wide DNA strand breaks and subsequent catastrophic DNA damage responses. These two mechanisms are independent of cancer driver mutations but are hindered by high MDM2 p60 expression. However, resistance to ACP52C mediated by MDM2 p60 can be sensitized by CASP2 inhibition. Additionally, derivatives of ACP52C conjugated with fatty acid alone or with a CASP2 inhibiting peptide show improved pharmacokinetics and reduced cancer burden, even in ACP52C-resistant cancers. This study enhances the understanding of ACP52C-induced cancer-specific apoptosis induction and supports the use of ACP52C in anticancer drug development.

NPFFR2 Contributes to the Malignancy of Hepatocellular Carcinoma Development by Activating RhoA/YAP Signaling

G protein-coupled receptors (GPCRs) are a diverse family of cell surface receptors implicated in various physiological functions, making them common targets for approved drugs. Many GPCRs are abnormally activated in cancers and have emerged as therapeutic targets for cancer. Neuropeptide FF receptor 2 (NPFFR2) is a GPCR that helps regulate pain and modulates the opioid system; however, its function remains unknown in cancers. Here, we found that NPFFR2 is significantly up-regulated in liver cancer and its expression is related to poor prognosis. Silencing of NPFFR2 reduced the malignancy of liver cancer cells by decreasing cell survival, invasion, and migration, while its overexpression increased invasion, migration, and anchorage-independent cell growth. Moreover, we found that the malignant function of NPFFR2 depends on RhoA and YAP signaling. Inhibition of Rho kinase activity completely restored the phenotypes induced by NPFFR2, and RhoA/F-Actin/YAP signaling was controlled by NPFFR2. These findings demonstrate that NPFFR2 may be a potential target for the treatment of hepatocellular carcinoma.

Prognosis after intrahepatic recurrence in the patients who underwent curative resection for hepatocellular carcinoma

Backgrounds/Aims

Intrahepatic recurrence is frequent result after hepatectomy for hepatocellular carcinoma (HCC). We analyzed the clinical results of patients who had the intrahepatic recurrences of HCC after curative surgical resections.

Methods

From January 2009 to December 2016, 320 patients underwent curative surgical resection for HCC in department of Surgery, Korea Cancer Center Hospital. After surgical resection, 155 patients had suffered HCC recurrence during follow-up period. Among them, 122 patients had only intrahepatic recurrence initially, who were included in this retrospective study. We analyzed about the period of the recurrence after surgery, treatment methods for the recurred tumors, and poor prognostic factors for survival after intrahepatic recurrences.

Results

Among the 122 patients, 83 patients had recurrence within 24 months after surgery. Thirty-eight patients underwent curative treatment for the recurred tumors (re-resection in 18, radiofrequency ablation in 20 patients). Non-curative treatments were performed in 77 patients (TACE in 68 patients, radiotherapy in 9 patients) and conservative management in 7 patients. Five-year survival rate of patients who underwent curative treatment is 86.4% (p≤0.001). Five-year survival rate of non-curative treatment is 55.7% (p≤0.001), conservative management is 0% (p=0.021). Among the clinical factors, non-curative treatment for recurred tumor, AFP level at the time of recurrence, size of recurred tumor were independent poor prognostic factors for survival after intrahepatic recurrences (p<0.001).

Conclusions

For the patients who had intrahepatic recurrent HCC after surgery, aggressive local treatment can improve the prognosis in selective cases. Further study is necessary to validate this retrospective investigation.

Comparison of the clinical results of surgical resection for extrahepatic cholangiocarcinomas: Hilar cholangiocarcinoma and mid-to-distal cholangiocarcinoma

Backgrounds/Aims

Hilar cholangiocarcinomas (HLC) are known to have worse prognoses than mid-to-distal cholangiocarcinomas (CBDC). We analyzed the clinical results of surgical resections for extrahepatic cholangiocarcinomas to validate the differences in the prognoses of HLC and CBDC.

Methods

Two hundred and eighty-one patients underwent curative surgical resections for extrahepatic cholangiocarcinomas at the Department of Surgery in the Korea Cancer Center Hospital. Among them, we analyzed the T2 and T3 patients and compared the clinical results between those with HLC (n=74) and those with CBDC (n=65).

Results

The rate of R1 resections was significantly higher in the HLC patients compared to the CBDC patients (31.1% vs 12.3%, p=0.006). The overall survival rate of the T2/T3 patients was lower in the HLC group than in the CBDC group (24.5% vs 51.7, p=0.039). The recurrence-free survival rate was 23.3% in the HCL patients and 50.9% in the CBDC patients (p=0.06). In the subgroup analysis, the survival rates were not different in patients who had lymph node metastases or in patients who underwent R1 resections between the HLC and CBDC patients. Poor independent prognostic factors for the overall and recurrence-free survival rates in the T2/T3 extrahepatic cholangiocarcinoma patients were the presence of lymph node metastases and the hilar locations of tumor.

Conclusions

HLC patients had poorer prognoses than CBDC patients. However, in patients with lymph node metastases, the prognosis was poor and was not different between the HLC and CBDC patients. Other adjuvant treatment methods are needed for extrahepatic cholangiocarcinoma patients with lymph node metastases to improve their prognoses.

A phase 2 multicenter study of stereotactic body radiotherapy for hepatocellular carcinoma: Safety and efficacy

BACKGROUND

Although several prospective studies have reported the efficacy of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC), treatment-related toxicity varies and has not been determined. Therefore, the authors evaluated the safety and efficacy of SBRT for patients with HCC in a hepatitis B virus-endemic area.

METHODS

This multicenter phase 2 trial enrolled patients with unresectable HCC. Patients received SBRT with 45 to 60 Gy in 3 fractions. To evaluate gastroduodenal toxicity, esophagogastroduodenoscopy (EGD) was performed before and 2 months after SBRT. The primary endpoint was treatment-related severe toxicity at 1 year after SBRT. The secondary endpoints were the 2-year local control, progression-free survival, and overall survival rates.

RESULTS

In total, 74 patients were enrolled between January 2012 and April 2015, and 65 eligible patients were analyzed. One patient experienced radiation-induced liver disease with acute grade ≥3 toxicity 1 month after SBRT. In addition, 1 patient had a grade 3 esophageal ulcer with stenosis 5 months after SBRT. The actuarial rate of treatment-related severe toxicity at 1 year was 3%. The pre-SBRT and post-SBRT EGD findings were not significantly different among the 57 evaluable patients who underwent EGD. The 2-year and 3-year local control rates were 97% and 95%, respectively. The progression-free and overall survival rates were 48% and 84% at 2 years, respectively, and 36% and 76% at 3 years, respectively.

CONCLUSIONS

With a median follow-up of 41 months, this prospective multicenter study demonstrated that SBRT for patients with HCC is well tolerated and is an effective treatment modality.

Protein arginine methyltransferase 5 is implicated in the aggressiveness of human hepatocellular carcinoma and controls the invasive activity of cancer cells

Protein arginine methyltransferase 5 (PRMT5) is a protein that catalyzes transfer of methyl groups to the arginine residues of proteins and is involved in diverse cellular and biological responses. While the participation of PRMT5 in cancer progression has been increasingly documented, its association with the invasive phenotype currently remains poorly understood. In the present study, we revealed that PRMT5 is overexpressed in human hepatocellular carcinoma (HCC) and in colon cancer and its depletion leads to the suppression of cell invasive activity via the reduction of the expression of MMP-2. Real-time quantitative RT-PCR analysis of 120 HCC patient tissues revealed the overexpression of PRMT5 in HCC and the association of PRMT5 with aggressive clinicopathological parameters, such as poorer differentiation (P=0.004), more frequent hepatic vein invasion (P=0.019), larger tumor size (P=0.011) and higher α-fetoprotein levels (P=0.020). Similarly to the data obtained with HCC, overexpression of PRMT5 was also displayed in colon cancer tissues, compared to matched non-tumor regions. Consistent with the significant association of the overexpression of PRMT5 with hepatic vein invasion in patient specimens, PRMT5 depletion via siRNA transfection led to a marked reduction in the invasion rate in both HCC and colon cancer cells. Reduced invasion associated with PRMT5 depletion was accompanied by a decrease in the expression of MMP-2. Collectively, our results indicated that PRMT5 overexpression in HCC and colon cancer cells contributed to their acquisition of aggressive characteristics, such as invasiveness, thus presenting a promising therapeutic target for the treatment of these diseases.

A graphene mesh as a hybrid electrode for foldable devices

A graphene mesh with arrays of micro-holes was fabricated on a polymer substrate using photolithography for use as an electrode in flexible devices. The optimal mesh structure with high optical transmittance and electrical conductivity was designed using a finite element method, in which the conductivity of the mesh was simulated as a function of structure, size, and periodicity of the hole array. The sheet resistance of the graphene mesh was lowered to that of a graphene monolayer by chemical doping and found to be 330 Ω Sq^-1 at 98.5% transparency. The figure of merit of the doped graphene mesh was calculated to be 106 at 98% transmittance, a value that has not yet been reported for any conventional transparent electrode material. Due to strong bonding between the polymer and substrate, the hybrid electrode composed of a silver nanowire (AgNW)/graphene mesh coated with an over-coating layer exhibited more stable electrical characteristics during mechanical fatigue deformation compared to a hybrid film composed of a AgNW/graphene sheet. The AgNW/graphene sheet underwent breakdown at less than 20 000 cycles in cyclic bending tests with 6.5% strain, but the AgNW/graphene mesh showed a 38% increase in resistance at 20 000 cycles and no breakdown even at 100 000 cycles. Therefore, in this study, we propose a hybrid structure composed of a AgNW/graphene mesh, which is optically and mechanically superior to AgNW/graphene sheets, and therefore suitable for application as a transparent electrode in foldable devices with long-term stability.

Promoter methylation of cysteine dioxygenase type 1: gene silencing and tumorigenesis in hepatocellular carcinoma

Backgrounds/Aims

Cysteine dioxygenase type 1 (CDO1) acts as a tumor suppressor and is silenced by promoter methylation in various malignancies. The relationship between the CDO1 methylation status and hepatocellular carcinoma (HCC) tumorigenesis was evaluated.

Methods

Using a HCC cell line (SNU423), an in vitro demethylation study was performed to confirm whether promoter methylation causes CDO1 down-regulation. The SNU423 cells transfected with the CDO1 cell function was compared to that of naïve cells. An in vivo study using immunohistochemical staining of HCC specimens that were collected from patients who underwent curative liver resection was also performed.

Results

CDO1 was activated after demethylation treatment in the HCC specimens. Moreover, tumor cell proliferation, colony-forming, migration, and invasion activities significantly decreased after CDO1 transfection (p<0.05). The percentage of tumors that were larger than 5 cm was higher in patients who had a lower expression of CDO1 (p=0.030). Vascular invasion and histological grade were independent prognostic factors for poor overall and recurrence-free survival. The degree of CDO1 expression was not an independent prognostic factor in this study's population.

Conclusions

These results suggested that methylation down-regulated CDO1 expression in the HCC cells. CDO1 methylation may be a potentially valuable diagnostic biomarker for HCC.

The mitochondrial hinge protein, UQCRH, is a novel prognostic factor for hepatocellular carcinoma

Alterations in mitochondrial respiration contribute to the development and progression of cancer via abnormal biogenesis, including generation of reactive oxygen species. Ubiquinol–cytochrome c reductase hinge protein (UQCRH) consists of the cytochrome bc1 complex serving respiration in mitochondria. In the present study, we analyzed UQCRH abnormalities in hepatocellular carcinoma (HCC) and its association with clinical outcomes of patients. UQCRH expression in HCC was determined via semiquantitative and quantitative real‐time reverse transcriptase polymerase chain reaction of 96 surgically resected HCC tissues positive for hepatitis B virus surface antigen. UQCRH was frequently overexpressed in HCC tissues (46.8%, based on 2.1‐fold cutoff). UQCRH overexpression was observed in HCCs with larger tumor size, poorer differentiation, or vascular invasion. Kaplan–Meier analysis revealed significantly shorter overall (P = 0.005) and recurrence‐free survival (P = 0.027) in patients with tumors overexpressing UQCRH. The prognostic impact of UQCRH was significant in subgroups of patients divided according to the α‐fetoprotein (AFP) level. The patient subgroup with higher AFP levels (≥20 ng/mL) exhibited significant differences in 5‐year overall (18.5% vs. 67.9%) and recurrence‐free survival rates (11.1% vs. 46.4%) between groups with and without UQCRH overexpression. In contrast, no marked survival differences were observed between subgroups with lower AFP levels (<20 ng/mL). Multivariate analysis defined UQCRH as an independent poor prognostic factor. Conclusively, our results indicate that UQCRH overexpression is correlated with poor outcomes of HCC patients. Furthermore, in patients grouped as high risk based on elevated AFP, lack of UQCRH overexpression could be a useful indicator for clinical treatment.

Five-year decreased incidence of surgical site infections following gastrectomy and prosthetic joint replacement surgery through active surveillance by the Korean Nosocomial Infection Surveillance System

BACKGROUND

Surveillance of healthcare-associated infection has been associated with a reduction in surgical site infection (SSI).

AIM

To evaluate the Korean Nosocomial Infection Surveillance System (KONIS) in order to assess its effects on SSI since it was introduced.

METHODS

SSI data after gastrectomy, total hip arthroplasty (THA), and total knee arthroplasty (TKA) between 2008 and 2012 were analysed. The pooled incidence of SSI was calculated for each year; the same analyses were also conducted from hospitals that had participated in KONIS for at least three consecutive years. Standardized SSI rates for each year were calculated by adjusting for SSI risk factors. SSI trends were analysed using the Cochran-Armitage test.

FINDINGS

The SSI rate following gastrectomy was 3.12% (522/16,918). There was a significant trend of decreased crude SSI rates over five years. This trend was also evident in analysis of hospitals that had participated for more than three years. The SSI rate for THA was 2.05% (157/7656), which decreased significantly from 2008 to 2012. The risk factors for SSI after THA included the National Nosocomial Infections Surveillance risk index, trauma, reoperation, and age (60-69 years). The SSI rate for TKA was 1.90% (152/7648), which also decreased significantly during a period of five years. However, the risk-adjusted analysis of SSI did not show a significant decrease for all surgical procedures.

CONCLUSION

The SSI incidence of gastrectomy and prosthetic joint replacement declined over five years as a result of active surveillance by KONIS.

Hepatectomy, combined with intraoperative radiofrequency ablation in patients with multiple hepatocellular carcinomas

Backgrounds/Aims

We compared the efficacy and safety of a hepatectomy, combined with intraoperative radiofrequency ablation to those of wider extent hepatectomy, alone, in patients with multiple hepatocellular carcinomas (HCCs).

Methods

Between January 2004 and December 2013, 78 patients with multiple HCCs underwent surgery. 25 patients were treated by hepatectomy, combined with intraoperative radiofrequency ablation (RFA) (group A), and 53 underwent hepatectomy only (group B). We retrospectively analyzed medical records to compare the clinical features of these two groups.

Results

Patients in group A had more limited resections (less than 2 segments) than those in group B (p<0.001). Patients in group A also tended to have fewer red blood cell transfusions than those in group B (p=0.060). Liver function- and surgery-related complications occurred only in group B. There were no in-hospital mortalities in both groups. The overall survival and disease-free survival outcomes were not significantly different between groups A and B (p=0.177 and p=0.305, respectively).

Conclusions

Hepatectomy combined with intraoperative RFA could be a safe and effective treatment option for patients with multiple HCCs, comparable to extended hepatectomy alone.

CD44 expression in patients with combined hepatocellular cholangiocarcinoma

PURPOSE

Combined hepatocellular cholangiocarcinoma (ChC) is a rare type of primary liver cancer, which is thought to have a poorer prognosis than hepatocellular carcinoma (HCC). Cancer stem cells are associated with tumorigenesis, tumor progression, recurrence, metastasis, and poor prognosis in several malignancies including HCC. The aim of this study was to investigate the expression pattern of cancer stem cell markers in ChC and HCC, and to evaluate whether this pattern correlated to patient prognosis.

METHODS

Thirteen patients who underwent curative hepatic resection for ChC and 13 patients who underwent curative hepatic resection for HCC (matched control cases) were included. Immunohistochemical staining for cancer stem cell markers (cytokeratin [CK]7, CK19, C-kit, cluster of differentiation [CD] 44, CD133, and epithelial cell adhesion molecule) was performed and clinical outcomes were analyzed retrospectively.

RESULTS

There was no significant difference in cancer stem cell marker expression between ChC and HCC. In ChC, the group that expressed CD44 showed earlier recurrence than the group that did not express CD44 (P = 0.040).

CONCLUSION

The expression of cancer stem cell markers in ChC did not show a different pattern compared to that found in HCC. The expression of cancer stem cell marker CD44 was associated with poor prognosis in patients with ChC.

High-dose stereotactic body radiotherapy correlates increased local control and overall survival in patients with inoperable hepatocellular carcinoma

BACKGROUND

Recent studies using stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) have reported high tumor response and local control. However, the optimal SBRT dose remains unknown, and it is still not clear whether a dose response relationship for local control (LC) and overall survival (OS) exist or not. We performed this study to determine whether a dose response relationship for LC and OS is observed in SBRT for inoperable HCC.

METHODS

Between 2003 and 2011, 108 patients with HCC were treated with SBRT. All patients were unsuitable for surgery or local ablation and had incomplete response to transarterial chemoembolization. Eighty-two patients with a longest tumor diameter (LD) less than or equal to 7.0 cm who were treated with 3-fraction SBRT and were analyzed. This cohort comprised 74 Child-Turcotte-Pugh (CTP) class A patients and 8 CTP class B7 patients. The median LD was 3.0 cm (range, 1.0-7.0 cm), and the median dose was 51 Gy (range, 33-60 Gy).

RESULTS

LC and OS rates at 2 years after SBRT were 87% and 63%, respectively, with a median follow-up duration of 30 months for all patients. The 2-year LC/OS rates for patients treated with doses of > 54, 45-54, and < 45 Gy were 100/71, 78/64, and 64%/30%, respectively (p = .009/p < .001). Multivariate analysis revealed that the SBRT dose (p = .005) and Barcelona Clinic Liver Cancer stage (p = .015) were significant prognostic factors for OS. Correlation analysis revealed a positive linear relationship between the SBRT dose and LC (p = .006, R = .899)/OS (p = .002, R = .940) at 2 years. Based on the tumor-control probability model, a dose of 54.8 Gy provides 2-year LC with a 90% probability. Five patients experienced grade 3 or higher gastrointestinal toxicity, and 6 had deteriorating of CTP score by greater than or equal to 2 within 3 months of SBRT.

CONCLUSIONS

This study demonstrated a dose response relationship for LC and OS with SBRT for HCC. Higher LC rates resulting from an increased dose may translate into survival benefits for patients with HCC.

Hepatic resection for hepatic metastases from gastric adenocarcinoma

PURPOSE

The effects of hepatic resection on patients with metastatic tumors from gastric adenocarcinomas are unclear. Therefore, we analyzed early clinical outcomes in patients who underwent surgical resection for hepatic metastases from gastric adenocarcinomas.

MATERIALS AND METHODS

From January 2003 to December 2010, 1,508 patients with primary gastric cancers underwent curative gastric resections at the Korea Cancer Center Hospital. Of these patients, 12 with liver-only metastases underwent curative hepatic resection. Their clinical data were analyzed retrospectively.

RESULTS

The median follow-up period was 12.5 months (range, 1~85 months); no operative mortalities or major complications were observed. Three patients underwent synchronous resections, and 9 underwent metachronous resections. In the latter group, the median interval between gastrectomy and hepatectomy for hepatic metastasis was 10.5 months (range, 5~47 months). The overall 1- and 5-year survival rates of these 12 patients were 65% and 39%, respectively, with a median overall survival of 31.0 months; 2 patients survived for >5 years.

CONCLUSIONS

Hepatic resection can be a feasible procedure for treating hepatic metastases from gastric adenocarcinomas. Although this study was small and involved only selected cases, the outcomes of the hepatic resections were comparable and long-term (>5 years) survivors were identified. Surgical resection of the liver can be considered a feasible option in managing hepatic metastases from gastric adenocarcinomas.

Extrahepatic recurrence of hepatocellular carcinoma after curative hepatic resection

Backgrounds/Aims

This study was designed to compare the recurrence patterns after curative hepatectomy, to compare the prognosis according to the initial site of metastasis, and to investigate the independent predictive factors associated with extrahepatic recurrence in hepatocellular carcinoma (HCC) patients after curative hepatectomy.

Methods

From January 2000 to July 2009, 307 patients underwent curative hepatectomies for HCC at our institution; 152 patients showed recurrences. Patients were divided into 2 groups according to their initial recurrence site: the intrahepatic recurrence (IHR) group and extrahepatic recurrence (EHR) group. The IHR group was comprised of 111 patients and the EHR group was comprised of 41 patients. The study investigated the preoperative, intraoperative, and postoperative factors related to the recurrence pattern retrospectively and compared the prognoses of the patients.

Results

A five-year survival rate after an initial recurrence was lower in the EHR group (21.5%) than the IHR group (36.3%) (p<0.001). The preoperative alpha-fetoprotein (AFP) level was an independent risk factor for extrahepatic recurrence (p=0.014).

Conclusions

Patients with a preoperative AFP level greater than 200 ng/ml have a higher incidence of extrahepatic metastases after a curative resection of HCC. Increased level of preoperative AFP is an indication for a short-term follow up hepatectomy.

Loss of PTEN induces microtentacles through PI3K-independent activation of cofilin

Loss of PTEN tumor suppressor enhances metastatic risk in breast cancer, although the underlying mechanisms are poorly defined. We report that homozygous deletion of PTEN in mammary epithelial cells induces tubulin-based microtentacles (McTNs) that facilitate cell reattachment and homotypic aggregation. Treatment with contractility-modulating drugs showed that McTNs in PTEN(-/-) cells are suppressible by controlling the actin cytoskeleton. Because outward microtubule extension is counteracted by actin cortical contraction, increased activity of actin-severing proteins could release constraints on McTN formation in PTEN(-/-) cells. One such actin-severing protein, cofilin, is activated in detached PTEN(-/-) cells that could weaken the actin cortex to promote McTNs. Expression of wild-type cofilin, an activated mutant (S3A), and an inactive mutant (S3E) demonstrated that altering cofilin phosphorylation directly affects McTNs formation. Chemical inhibition of PI3K did not reduce McTNs or inactivate cofilin in PTEN(-/-) cells. Additionally, knock-in expression of the two most common PI3K-activating mutations observed in human cancer patients did not increase McTNs or activate cofilin. PTEN loss and PI3K activation also caused differential activation of the cofilin regulators, LIM-kinase1 (LIMK) and Slingshot-1L (SSH). Furthermore, McTNs were suppressed and cofilin was inactivated by restoration of PTEN in the PTEN(-/-) cells, indicating that both the elevation of McTNs and the activation of cofilin are specific results arising from PTEN loss. These data identify a novel mechanism by which PTEN loss could remodel the cortical actin network to facilitate McTNs that promote tumor cell reattachment and aggregation. Using isogenic MCF-10A PTEN(-/-) and PIK3CA mutants, we have further demonstrated that there are clear differences in activation of cofilin, LIMK and SSH between PTEN loss and PI3K activation, providing a new evidence that these mutations yield distinct cytoskeletal phenotypes, which could have an impact on tumor biology.

Fat Tissue Infiltration into the Pancreas Parenchyme and Its Effect on the Result of Surgery

Purpose

In Korea, there are few reports regarding the infiltration of fat tissue in pancreatic parenchyma in surgically resected organs. It is necessary to ascertain the correlation between the presence of fat tissue in the resection margin of the pancreas and the surgery outcome.

Methods

Fifty four patients who underwent pancreatic resection from Jan. 2007 to Nov. 2008 were enrolled in this study. Pathologic examination was performed to determine the presence of fat tissue in resected pancreatic parenchyma. Statistical correlation between the presence of fat tissue with clinical parameters and postoperative complication rates was analyzed.

Results

Among the specimens of all fifty four patients, fat tissue was found in 32 specimens of patients (59.3%). Female gender and patients whose body mass index exceeded 24 kg/m² were statistically correlated with the presence of the fat tissue in pancreatic parenchyma. There was no statistical relationship between infiltration of fat tissue with postoperative complications.

Conclusion

This study may serve as the base data for study in radiological imaging in detecting pancreatic tissue. A further larger scaled study is needed to validate the result of this study.

Metastatic breast tumors express increased tau, which promotes microtentacle formation and the reattachment of detached breast tumor cells

The cytoskeletal organization of detached and circulating tumor cells (CTCs) is currently not well defined and may provide potential targets for new therapies to limit metastatic tumor spread. In vivo, CTCs reattach in distant tissues by a mechanism that is tubulin-dependent and suppressed by polymerized actin. The cytoskeletal mechanisms that promote reattachment of CTCs match exactly with the mechanisms supporting tubulin microtentacles (McTN), which we have recently identified in detached breast tumor cells. In this study, we aimed to investigate how McTN formation is affected by the microtubule-associated protein, tau, which is expressed in a subset of chemotherapy-resistant breast cancers. We demonstrate that endogenous tau protein localizes to McTNs and is both necessary and sufficient to promote McTN extension in detached breast tumor cells. Tau-induced McTNs increase reattachment of suspended cells and retention of CTCs in lung capillaries. Analysis of patient-matched primary and metastatic tumors reveals that 52% possess tau expression in metastases and 26% display significantly increased tau expression over disease progression. Tau enrichment in metastatic tumors and the ability of tau to promote tumor cell reattachment through McTN formation support a model in which tau-induced microtubule stabilization provides a selective advantage during tumor metastasis.

Targeting novel microtentacles to reduce the adhesion of circulating tumor cells to blood vessel walls

Abstract #2044

Detached human breast tumor cell lines produce novel protrusions of the plasma membrane that promote reattachment of tumor cells to each other and extracellular matrix. We have termed these protrusions “microtentacles” due to clear mechanistic distinctions from either actin-based filopodia/invadopodia or tubulin-based cilia.&#x2028; &#x2028; Compelling in vivo studies show that a mechanism consistent with microtentacles is responsible for the attachment of circulating tumor cells to blood vessel walls. Human breast tumor cell lines that display a disorganized actin cortex and hallmarks of epithelial-to-mesenchymal transition produce higher frequencies and greater extension of microtentacles. Conversely, some current and proposed tumor drugs that target the cytoskeleton actually increase microtentacles. While many cancer therapies are directed against the process of cell division, it remains important to consider the effects of these drugs on the invasive characteristics of tumor cells. Our current research has determined that microtentacles are composed of coordinated filaments of vimentin and detyrosinated tubulin. Previous studies indicate that elevated levels of vimentin and detyrosinated tubulin in tumors predict poor patient outcome, although the specific mechanisms remain unclear. Time-lapse video microscopy also indicates that the rapid extension and dynamic motion of microtentacles relies on kinesin activation. Again, our results suggest that the kinesin responsible is a conventional kinesin, rather than the mitotic kinesins commonly targeted by cancer therapies. We propose that the independent roles of vimentin, detyrosinated tubulin and kinesin in tumor metastasis could result from their interdependent contributions to microtentacle formation. Since large epithelial tumor cells are often fragmented in narrow capillaries, we are targeting microtentacles to promote the fragmentation of circulating tumor cells in the capillaries of the lung. We are currently using time-lapse confocal microscopy of tumor cells circulating in intact blood vessels and whole-animal optical imaging to define therapies that reduce microtentacle-dependent adhesion of circulating breast tumor cells during metastasis.&#x2028; &#x2028; This image shows circulating tumor cells (red) adhering to the walls of an intact blood vessel (green).

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2044.

Hypophosphatemia after live donor right hepatectomy

BACKGROUND

It is known that hypophosphatemia can frequently develop after hepatectomy and may result from an increased renal phosphate leak. However, its clinical significance has not been well defined in live donor right hepatectomy (LDRH). The purpose of this study was to investigate the correlation between postoperative hypophosphatemia and both donor morbidity and the degree of hepatic resection in LDRH.

METHODS

In all, 88 live liver donors were enrolled, who had undergone right hemihepatectomy between January 2002 and December 2005. Based on the severity of the postoperative hypophosphatemia, we divided the donors into 3 groups: mild (1.5-2.5 mg/dL, n = 30), moderate (1.0-1.5 mg/dL, n = 41), and severe (<1.0 mg/dL, n = 17), and we compared the incidence of complications among these groups. In addition, we investigated the possible correlation between the nadir phosphorus levels and both remnant liver volume and alkaline phosphate (ALP) levels.

RESULTS

All donors developed hypophosphatemia postoperatively. The mean value of the nadir phosphorus levels was 1.4 +/- 0.04 mg/dL. However, no significant difference was observed in the incidence of postoperative complications among the hypophosphatemia groups. The phosphorus level was positively correlated with the remnant liver volume (r = 0.389, P < 0.001), but it was negatively correlated with a postoperative increase in the ALP (r = -0.276, P = 0.014).

CONCLUSIONS

Hypophosphatemia developed very frequently after LDRH. However, transient hypophosphatemia was unlikely to lead to severe complications in healthy donors. Therefore, based on the serum level, oral or intravenous phosphorus replacement treatment might be more appropriate than routine aggressive replacement by TPN. In addition, although the factors responsible for posthepatectomy hypophosphatemia have not been identified, they might be substances that are associated with hepatic regeneration.

Effect of preoperative biliary drainage on surgical results after pancreaticoduodenectomy in patients with distal common bile duct cancer: Focused on the rate of decrease in serum bilirubin

AIM: To examine if the rate of decrease in serum bilirubin after preoperative biliary drainagecan be used as a predicting factor for surgical complications and postoperative recovery after pancreaticoduodenectomy in patients with distal common bile duct cancer.

METHODS: A retrospective study was performed in 49 consecutive patients who underwent pancreaticoduodenectomy for distal common bile duct cancer. Potential risk factors were compared between the complicated and uncomplicated groups. Also, the rates of decrease in serum bilirubin were compared pre- and postoperatively.

RESULTS: Preoperative biliary drainage (PBD) was performed in 40 patients (81.6%). Postoperative morbidity and mortality rates were 46.9% (23/49) and 6.1% (3/49), respectively. The presence or absence of PBD was not different between the complicated and uncomplicated groups. In patients with PBD, neither the absolute level nor the rate of decrease in serum bilirubin was significantly different. Patients with rapid decrease preoperatively showed faster decrease during the first postoperative week (5.5 ± 4.4 &mgr;mol/L vs -1.7 ± 9.9 &mgr;mol/L, P = 0.004).

CONCLUSION: PBD does not affect the surgical outcome of pancreaticoduodenectomy in patients with distal common bile duct cancer. There is a certain group of patients with a compromised hepatic excretory function, which is represented by the slow rate of decrease in serum bilirubin after PBD.

Classification and prognosis of intrahepatic biliary stricture after liver transplantation

Intrahepatic biliary stricture (IHBS) after liver transplantation (LT) may develop in patients with hepatic artery thrombosis, chronic rejection, or ABO incompatibility, as well as in patients with prolonged warm ischemia in non-heart-beating donor (NHBD) LT. However, the clinical course and methods of management have not been well defined for IHBSs to date. Thus, the purpose of this study was to provide a classification of post-LT IHBS and to investigate patient prognosis. Forty-four patients who developed IHBS after NHBD LT were enrolled. On the basis of the cholangiographic appearance, patients were classified into 4 groups: unilateral focal (UF, n=8), confluence (CO, n=10), bilateral multifocal (BM, n=21), and diffuse necrosis (DN, n=5). The UF type was defined as cases with stricture only in the segmental branch of the unilateral hemiliver; the CO type in cases with several strictures at confluence level; and the BM type in cases with multiple strictures bilaterally. Cases with diffuse obliteration of peripheral ducts or destruction of the central architectural integrity, over a long segment, were classified as the DN type. Five patients with the CO type required several interventions requiring biliary dilatation, yet all patients with the UF or CO type had a good prognosis. Among the patients with the BM type, 3 patients (14.3%) died or underwent retransplantation due to biliary complications, and 7 (33.3%) required repeated interventions for >1 year without improvement. Moreover, among 5 patients classified as the DN type, 1 (20%) died of biliary sepsis, 2 (40%) underwent retransplantation, and the remaining 2 (40%) did not recover from persistent jaundice and life-threatening cholangitis despite multiple interventions. In conclusion, all patients classified as UF or CO had a good outcome with or without additional interventions. However, all patients with the DN type and about half the patients with the BM type did not recover from life-threatening complications, despite repeated aggressive interventions; early retransplantation was therefore the only treatment option for these patients.

Acute graft versus host disease following living donor liver transplantation: first Korean report

Graft-versus-host disease (GVHD) after liver transplantation is an uncommon fatal complication and no effective preventive or therapeutic measure is available. We report the first case of fatal GVHD after liver transplantation in Korea. A 51-year-old male underwent living donor liver transplantation for hepatitis B virus (HBV)-related liver cirrhosis and hepatocellular carcinoma. The donor was his 21-year-old son. The patient was discharged uneventfully. However, 56 days after transplantation, he was readmitted due to watery diarrhea, which was subsequently accom-panied by a skin rash and leukopenia. Diagnosis was made by skin biopsy and by donor DNA chimerism testing in recipient tissue. A one-way donor-recipient HLA match was identified by HLA typing for both donor and recipient. The patient was treated by increasing immunosuppression, but died of septic shock. A pretransplant HLA typing of both donor and recipient should be taken, and in cases of one-way donor-recipient HLA matching, liver transplantation should be avoided.

Outcomes of hepatic resection for a single large hepatocellular carcinoma

BACKGROUND

The proper role of surgical resection, given the various treatment modalities available, needs to be further clarified in patients with a single large hepatocellular carcinoma (HCC). To evaluate the role of surgical resection in this group of patients, we studied the long-term outcomes of patients that received hepatic resection for a single large (> 5-10 cm in diameter) HCC.

METHODS

The clinicopathologic data and long-term outcomes of 61 patients with a single large HCC (> 5-10 cm in diameter; L group) were compared with those of 169 patients with a single small HCC (< or = 5 cm; S group). Prognostic factors were evaluated by univariate and multivariate analysis.

RESULTS

Operative mortality rates were low in both groups (0.6% in group S and 1.6% in group L), and the incidence of postoperative hepatic failure was rare even in group L (1.6%). The cumulative 5-year overall survival rate in group S was 59.0%, whereas in group L it was 52.9% (p = 0.385), and the corresponding cumulative 5-year disease-free survival rates were 44.1% and 31.7%, respectively (p = 0.063). Child class B was found to predict poor overall and disease-free survival by multivariate analysis versus Child class A in both groups. The presence of microvascular invasion was also identified as a significant prognostic factor, but it only affected disease-free survival in the two groups.

CONCLUSIONS

Single large HCCs do not require a large extent of hepatic resection and the associated increased risk of postoperative liver failure. The long-term survival of patients with a single large HCC is as good as that of patients with a single small HCC. We conclude that hepatic resection is a safe and effective therapy for single large HCCs.

Anatomic versus non-anatomic resection for small single hepatocellular carcinomas

BACKGROUND/AIMS

Anatomical hepatectomy for small hepatocellular carcinomas (HCCs) is widely preferred but evidence concerning its benefits is inadequate. The aim of this study was to determine whether patient outcome is influenced by the method used to treat small single HCCs.

METHODOLOGY

An analysis was performed on 168 patients who underwent curative hepatectomy for a single HCC smaller than 5cm between Jan 1998 and Dec 2001 at Seoul National University Hospital. Ninety-nine of these patients underwent anatomic resection and 69 patients non-anatomic resection. Overall survival rates, disease-free survival rates, and prognostic factors for survival and recurrence were analyzed.

RESULTS

The cumulative 1-, 3- and 5-year overall survival rates were 86.9%, 73.6% and 65.5% in the anatomic resection group, and 88.4%, 63.8% and 49.7%% in the non-anatomic resection group, respectively (P = 0.032). And, the cumulative 1-, 3- and 5-year disease-free survival rates were 77.8%, 58.6% and 54.4% in the anatomic resection group and 62.3%, 42.0% and 28.6% in the non-anatomic resection group, respectively (P = 0.003). Anatomic resection was confirmed to be an independent favorable factor of disease-free survival by multivariate analysis.

CONCLUSIONS

Anatomic resection for single small HCCs is superior to non-anatomic resection.

Safety of modified extended right hepatectomy in living liver donors

In living donor liver transplantation (LDLT), the standard right graft has been adopted by many centers to meet the metabolic demands of large recipients. In conventional right liver graft, congestion at anterior section may be problematic especially when graft volume is insufficient. We previously introduced a technical aspect of modified extended right hepatectomy (MERH), in which the middle hepatic vein was excavated by preserving the entire segment 4 (Sg4) to the donor. In this report, we investigated the safety of donors who received MERH. Between August 2002 and July 2005, 97 donors underwent right liver donation. MERH was considered when remnant-left liver volume exceeded 35% of whole liver. Eighteen donors underwent MERH (MERH group, n=18). We compared the clinical outcomes of MERH group with those of donors who underwent conventional right hepatectomy (RH) with remnant liver volume exceeding 35% (RH group, n=37). No donor mortality occurred. No intra-operative transfusion and no re-operation were performed. There were no differences in operative time (290.8 min in MERH group vs. 297.0 min in RH group, respectively), blood loss (453.3 ml vs. 426.5 ml), and postoperative hospital stay (12.5 days vs. 12.8 days) between the two groups (P>0.05). Period of drain removal was longer in MERH group (12.5 days vs. 9.4 days, P<0.05). But, there was no difference in complication rate between the two groups (11/18 vs. 23/37, P>0.05). Computed tomography scan showed that congestion of Sg4 was occurred in 13 out of 18 MERH donors in early postoperative period, but all recovered at 4 months. The regeneration of the remnant liver after MERH and RH were similar (209.8% vs. 200.0% at 4 months, P>0.05). Our results show that MERH did not impair recovery or liver regeneration in donors, and indicate that MERH can be safely done in adult LDLT when the remnant liver exceeds 35%.

Preoperative lamivudine therapy in HBV DNA positive recipients: is it always necessary?

BACKGROUND/AIMS

Long-term preoperative lamivudine therapy has been recommended for patients with positive HBV DNA to suppress HBV replication before liver transplantation. However, it is unclear whether preoperative lamivudine therapy is mandatory in HBV DNA positive patients to reliably prevent HBV recurrence or whether transplantation should be delayed to allow time for sufficient preoperative lamivudine therapy.

METHODOLOGY

From January 2000 to January 2004, thirty-eight patients serum positive for HBV DNA who survived more than 3 months after transplantation and received postoperative combination prophylaxis with hepatitis B immune globulin and lamivudine were enrolled.

RESULTS

Total 2-year recurrence rate was 8.7%. When these 38 patients were divided into two groups according to preoperative lamivudine therapy duration: group 1 (n = 11) 4 weeks or more and group 2 (n = 27) less than 4 weeks, recurrences were detected in 3 (27.2%) and 4 (14.8%) patients in groups 1 and 2, respectively, i.e. a similar recurrence rate in both groups (p = 0.390). Moreover, in a subgroup of 20 patients who received preoperative lamivudine therapy for less than one week, only one (5%) experienced HBV recurrence.

CONCLUSIONS

Our findings indicate that postoperative combination prophylaxis is effective and that preoperative lamivudine therapy is unlikely to be obligatory despite a positive preoperative serum HBV DNA status.

An artificial vascular graft is a useful interpositional material for drainage of the right anterior section in living donor liver transplantation

Congestion in the anterior section in a right liver (RL) without a middle hepatic vein (MHV) may lead to graft dysfunction. To solve this problem, an RL draining MHV branches with autologous or cryopreserved vessels can be introduced. However, these vessels are often unavailable, and their preparation is time-consuming. An expanded polytetrafluoroethylene (ePTFE) graft may be used for anterior section drainage. Between February and November 2005, 26 recipients underwent RL liver transplantation draining MHV branches with an ePTFE graft (group P). Twenty-six ePTFE grafts (6 or 7 mm in internal diameter) drained 35 MHV branches on the back table to the graft right hepatic vein or to the recipient's inferior vena cava. The patency of the ePTFE graft was checked with computed tomography scans of the liver. The outcome of group P was compared with those of an RL group with MHV (group M, n=17) and an RL group without reconstruction of MHV or its tributaries (group R, n=85). The 1-month and 4-month patency rates (PRs) of the ePTFE grafts were 80.8% (21/26) and 38.5% (10/26). All showing early obstruction of the ePTFE graft had congestion in the anterior section, but all showing late obstruction were asymptomatic. The 1-month PRs of group P were comparable to, but the 4-month PRs were lower than, those of group M (both 94.1%; P<0.05). However, 1-year patient and graft survival rates of group P (both 100%) were comparable to those of group M (94.1% and 100%) and better than those of group R (83.5% and 88.2%; P<0.05). In conclusion, the early PR of group P was good, and late obstruction of the ePTFE graft had no impact on congestion in the anterior section or patient survival. Therefore, an ePTFE graft may be a useful interposition material for anterior section drainage in RL transplantation without serious complications.

Three-quarters of right liver donors experienced postoperative complications

A donor right hepatectomy (RH) is associated with a higher rate of morbidity than a left hepatectomy. Therefore, the precise morbidity should be known to improve the success of donor RH implementation. However, the rate of complication varies according to the individual definition of morbidity. This study prospectively analyzed the outcomes of 83 consecutive living donor RHs between January 2002 and July 2004 using a standardized classification of the severity of complications. The morbidity was classified using the modified Clavien system: grade I for minor complications; grade II for potentially life-threatening complications requiring pharmacological treatment; grade III for complications requiring invasive intervention; grade IV for complications causing organ dysfunction requiring intensive care unit management; and grade V complications resulting in the death of the patient. The donors were followed-up regularly for at least 12 months. No donor death or relaparotomy was noted. Overall, 65 out of 83 donors (78.3%) experienced postoperative complications: grades I, II, III, IV, and V complications in 64 (77.1%), 11 (13.3%), 1 (1.2%), 0, and 0 patients, respectively. The most common grade I complications were hyperbilirubinemia (n = 31) and pleural effusion (n = 31), and bile leakage in grade II (n = 7). The bilirubin and alanine aminotransferase levels were normal in 92.7% of donors at the 1-year follow-up. In conclusion, although most of these adverse events were minor and self-limited, 78% of right liver donors still experienced morbidity. Therefore, continuous standardized reporting of the donor morbidity as well as meticulous surgery and intensive care are essential for the success of donor RH implementation.

A revised scoring system utilizing serum alphafetoprotein levels to expand candidates for living donor transplantation in hepatocellular carcinoma

BACKGROUND

The development of living donor liver transplantation has stimulated discussion about the expansion of tumor burden limits for patients with hepatocellular carcinoma (HCC). Although serum alphafetoprotein (AFP) level is an important predictor of tumor recurrence, it is not included in the existing selection criteria for HCC in transplantation.

METHODS

We performed a retrospective study of 63 consecutive adults with HCC diagnosed preoperatively who received living donor liver transplantation from February 1999 to September 2005 and survived over 1 month. The authors devised new scoring criteria that included tumor size, tumor number, and pretransplant AFP level as prognostic factors. The score of each parameter was classified from 1 to 4 points (tumor size, < or =3, 3.1 to 5, 5.1 to 6.5, >6.5 cm; tumor number, 1, 2 or 3, 4 or 5, or > or =6 nodules; and AFP, < or =20, 20.1 to 200, 200.1 to 1000, >1000 ng/mL, respectively). We defined that 3 to 6 points and 7 to 12 points were "transplantable" and "nontransplantable," respectively. The usefulness of the devised criteria was then investigated as a method of selecting candidates with HCC for transplantation.

RESULTS

The candidates' overall 3-year survival rate and recurrence-free survival rate were 67% and 70% after transplantation, respectively. Based on pretransplant imaging, 37 (59%), 41 (65%), and 44 (70%) of the 63 patients met the Milan criteria, University of Californica, San Francisco (UCSF) criteria, and the new scoring criteria. Their 3-year survival rates were 80%, 78%, and 79%, respectively. Moreover, based on posttransplant data, the scoring criteria correlated with the risk of death and HCC recurrence (Milan criteria, P = .005 and .001; UCSF criteria, P = .013 and .001 for death and recurrence; scoring criteria, P < .001 for both).

CONCLUSIONS

The newly devised scoring criteria could expand usefully current selection criteria for transplantation without detrimentally affecting outcome in the living donor transplantation setting for HCC.

Hepatic steatosis is associated with intrahepatic cholestasis and transient hyperbilirubinemia during regeneration after living donor liver transplantation

A clear understanding of the mechanisms in steatotic livers that trigger cholestasis or hyperbilirubinemia after living donor liver transplantation (LDLT) remains elusive. We hypothesized that microarchitectural disturbance might occur within regenerating steatotic livers without impairment of hepatic proliferative activity. Liver biopsy specimens from 67 LDLT recipients taken at the 10th postoperative day were scored for the numbers of portal tracts per area (nPT/A) of liver tissue and for intrahepatic cholestasis, and immunostained by proliferating cell nuclear antigen (PCNA) and Ki-67. The preoperative degree of macrovesicular steatosis (MaS) was independently associated with cholestasis after LDLT (P < 0.001). Serum total bilirubin results on the 1st, 3rd, and 7th days post-LDLT in MaS+ (5-30% of MaS; n = 37) patients were significantly higher than those in MaS- (<5% of MaS; n = 30) patients (P = 0.030, 0.042, and 0.019, respectively). Mean numbers of positively stained hepatocytes were 53.1 +/- 12.0 in patients with MaS and 48.0 +/- 17.1 in those without MaS by PCNA (P = 0.390), and 24.4 +/- 10.5 and 24.0 +/- 14.0 by Ki-67 (P = 0.940). However, a significant negative correlation was found between the degree of MaS and nPT/A (P = 0.013), and nPT/A was correlated with the grade of histological cholestasis (r = 0.350, P = 0.039). Intrahepatic cholestasis and hyperbilirubinemia after LDLT could be caused by scanty morphologic change of portal tract during steatotic liver regeneration.

Liver transplantation for hepatocellular carcinoma in patients who do not meet the Milan criteria

BACKGROUND

To expand the Milan criteria, prognostic factors other than size and number of tumor may be necessary. We analyzed outcome and prognostic factors in patients with hepatocellular carcinoma (HCC) exceeding Milan criteria to select favorable group of patients.

METHODS

Between November 1997 and December 2005, 104 cases of liver transplantation for patients with HCC were performed at our center. Twenty-four patients did not meet the Milan criteria preoperatively. Among these 24 patients, 19 had no major vascular invasion at the time of surgery. We analyzed the survival and prognostic factors of these 19 patients. The mean follow-up period was 33 months (range 6-89).

RESULTS

Three-year survival rate in 19 patients was 67.4%. Three-year survival rates were significantly higher when preoperative alpha-fetoprotein was less than 400 ng/ml (86.2 vs. 0%, p<0.001) when Edmonson-Steiner's histological grade 1 or 2 (100 vs. 40%, p = 0.036) and when microvascular invasion was absent (78.6 vs. 30%, p = 0.039).

CONCLUSION

If vascular invasion is absent in preoperative radiological studies, and the preoperative alpha-fetoprotein is less than 400 ng/ml, our findings suggest a good prognosis after liver transplantation for HCC patients who do not meet the Milan criteria.

The clinical significance of early histological rejection with or without biochemical abnormality in adult living donor liver transplantation for hepatitis B virus related end stage liver disease

There is no agreement regarding the treatment of early allograft rejection (EAR) in adult living donor liver transplantation (LDLT). A protocol biopsy was performed in 62 adult LDLT recipients. Twenty-one patients (33.9%) had histological evidence of EAR. Of these, 14 patients had biochemical abnormalities and seven patients had no associated biochemical abnormalities. None of the seven patients with subclinical EAR (11.3% of the entire study population) were treated, and no subsequent rejection was observed. Gender mismatch (female-to-male) was the single independent risk factor for histological EAR [odds ratio (OR) = 13.458; 95% confidence interval (CI), 1.836-98.649] and the cumulative probability for a subsequent rejection was higher in patients with EAR (OR = 11.085; 95% CI, 1.221-100.654). However, the actuarial 1 year patient and graft survival rate in patients with EAR (81.0% and 85.5%) were similar to those without EAR (92.7% and 97.25%; P = 0.127 and 0.302, respectively). The presence of an initial biochemical abnormality was an independent risk factor for both a decreased patient survival (OR = 5.827; 95% CI, 1.095-31.017; P = 0.039) and graft loss (OR = 20.646; 95% CI, 2.044-208.524; P = 0.010). Subsequent rejection developed more frequently in patients with EAR. However, the survival is not determined by the presence of EAR but by the presence of a biochemical abnormality.

The role of (18)F-FDG-PET imaging for the selection of liver transplantation candidates among hepatocellular carcinoma patients

Positron emission tomography (PET) using F-18 fluoro-2-deoxy-d-glucose ((18)F-FDG) is now well established as a noninvasive diagnostic tool for the detection of a variety of malignant tumors. However, in the case of hepatocellular carcinoma (HCC), several investigators have reported controversial conclusions and an inadequate sensitivity for PET (50-55%). Nevertheless, a high positive rate of (18)F-FDG accumulation has been reported in patients with high-grade HCC and in those with markedly elevated alpha-fetoprotein (AFP) levels. Here, we retrospectively reviewed 38 HCC cases that received liver transplantation (LT) at our center between November 2000 and July 2004 and underwent whole-body PET imaging. (18)F-FDG uptake was assessed in the liver, and its prognostic significance was investigated. Of 38 patients enrolled, 13 patients had positive PET scans for a liver tumor. When we analyzed the association between tumor factors and PET+ (greater PET lesion uptake) in the liver, preoperative AFP level and vascular invasion were found to be significantly associated with PET+ (P = 0.003 and P < 0.001, respectively). However, the association between histological grade and PET+ findings did not reach statistical significant difference (P = 0.074). Moreover, the 2-year recurrence-free survival rate of PET- patients was significantly higher than that of PET+ patients (85.1% vs. 46.1%) (P = 0.0005). Of 6 PET+ patients who met the Milan criteria, 4 patients (66.7%) had recurrence, but all 20 PET- patients who met the Milan criteria were recurrence free. Thus, PET imaging could be a good preoperative tool for estimating the post-LT risk of tumor recurrence, because histological grade and vascular invasion cannot be determined preoperatively. Importantly, our results indicate that tumor recurrence can be highly anticipated for PET-imaging-positive HCC patients who satisfy the Milan criteria. We advise that PET+ HCC patients be selected cautiously for LT.

Hypoattenuation in unenhanced CT reflects histological graft dysfunction and predicts 1-year mortality after living donor liver transplantation

Early postoperative graft function assessments are essential after living donor liver transplantation (LDLT) to predict patient and graft outcome. Computed tomography (CT) is usually used to evaluate various complications and parenchymal abnormalities after LDLT. Here, we attempted to determine the prognostic values of CT attenuation changes of grafts for predicting 1-year patient survival. Liver attenuation indices (LAIs), derived from differences between hepatic and splenic attenuations, were calculated on unenhanced CT images obtained 10 days after LDLT in 62 adult LDLT recipients between September 2002 and August 2004. Patients were assigned to 1 of 2 groups according to LAI value on the 10th postoperative day, as follows: group L (LAI < or = 5, n = 14) or group H (LAI > 5, n = 48). Parenchymal dysfunction scores, summed parameters for histological dysfunction including both portal tract and centrilobular features, were also assessed on the 10th postoperative day using liver biopsy specimens. Histological parenchymal dysfunction, especially in the centrilobular area, in terms of cholestasis, centrilobular necroinflammation, central vein fibrosis, steatosis, mononuclear infiltrates, and hepatocyte ballooning, was more prominent in group L than in group H, while that in the portal area was similar between the 2 study groups. Significant negative linear correlations were observed between LAI and parenchymal dysfunction scores (r = 0.486, P < 0.001). Group L patients showed lower 1-year survival (69.7%) than group H patients (95.8%; P = 0.0002). Moreover, group H patients died with a functioning graft (n = 3), whereas group L patients died of graft failure (n = 6). After multivariate analysis, LAI alone remained independently associated with 1-year mortality (P = 0.014; odds ratio = 0.845; 95% confidence interval, 0.739-0.967). The sensitivity and specificity of LAI were 84.6% and 75%, respectively, and LAI outperformed MELD score as a predictor of 1-year mortality after LDLT by receiver operating characteristic curve analysis. In conclusion, LAI, as determined by unenhanced CT 10 days after LDLT, well predicts 1-year patient survival after LDLT.

Calibration and standardization of the emission light path of confocal microscopes

Recently, there has been a large expansion in the usage of optical microscopes for obtaining quantitative information from biological samples in order to determine fundamental biological information such as molecular kinetics and interaction, and heterogeneity within cell populations. Consequently, we built a highly stable, uniform, isotropically emitting and convenient-to-use light source, and designed image analysis procedures for calibrating the emission light path of optical microscopes. We used the source and procedures to analyse the quantitative imaging properties of a widely used model of laser scanning confocal microscope. Results showed that the overall performance was as high as could be expected given the inherent limitations of the optical components and photomultiplier tubes. We observed that the photon detection efficiency did not vary with photomultiplier tube gain and that the highest dynamic range was achieved with relatively low gain and 12-bit digitization. Practical applications of the light source for checking the transmission of optical components in the emission light path are presented.

Effects of ADP on different inhibitory properties of brain glutamate dehydrogenase isoproteins by perphenazine

Incubation of glutamate dehydrogenase isoproteins (GDH I and GDH II) from bovine brains with perphenazine resulted in a time-dependent loss of enzyme activity. 2-Oxoglutarate and NADH, separately or together, gave partial but not complete protection against the inhibition. Although there were no detectable differences between GDH I and GDH II in inhibition by perphenazine in the absence of ADP, the sensitivities to the inhibition by the drug were significantly distinct for the two isoproteins in the presence of ADP. Low concentrations of ADP (0.05-0.20 mM) did not interfere with the inhibition of GDH I and GDH II by perphenazine. However, in the presence of high concentrations of ADP (0.5-1.0 mM), inhibitory effects of perphenazine on GDH isoproteins were significantly diminished as determined by enzyme kinetics and quantitative affinity chromatography on perphenazine-Sepharose. GDH I was more sensitively reacted with ADP than GDH II on the inhibition by perphenazine. Since physiological ADP levels can vary from 0.05 to > 1.0 mM depending on the rate of oxidative phosphorylation, our results suggest a possibility that two types of GDHs are differently regulated by the antipsychotic actions of perphenazine depending on the physiological concentrations of ADP. GTP and L-leucine, other well-known allosteric regulators, did not affect the inhibitory actions of perphenazine on bovine brain GDH isoproteins.

An essential histidine residue in GTP binding domain of bovine brain glutamate dehydrogenase isoproteins

Greater than 90% of the original activity of the enzymes remained after modification of histidine residues of glutamate dehydrogenase (GDH) isoproteins from bovine brains with diethyl pyrocarbonate (DEPC). This suggests that the DEPC modified histidine residues are not critically involved in the catalysis of the GDH isoproteins. The influence of DEPC modified histidine residue(s) on binding of GTP to GDH isoproteins was investigated by protection studies. These studies showed that inhibition of GDH isoproteins by GTP was protected by preincubation of GDH isoproteins with DEPC. The amount of protection was dependent on the concentration of DEPC. The GTP inhibition was fully protected by preincubation of GDH isoproteins with DEPC at saturating concentrations. These results indicate that the histidine residues may play an important role in the GTP binding on GDH isoproteins. Spectrophotometric studies showed that three histidine residues per enzyme subunit were able to react with DEPC in the absence of GTP, whereas two histidine residues per enzyme subunit interacted with DEPC when the enzymes were preincubated with GTP. These results indicate that one of the histidine residues is involved in the GTP binding domain of GDH isoproteins. The quantitative affinity chromatographic studies showed that the influence of GTP on the binding of GDH isoproteins to DEPC-Sepharose was significantly distinct for the two GDH isoproteins. GDH I was more sensitively affected by GTP than GDH II in the binding affinity for DEPC-Sepharose. ADP, another well-known allosteric regulator, showed no significant changes in the interaction of DEPC with GDH isoproteins.

A case of nodular scleritis in association with Behcet's disease

Approximately 50% of patients with scleritis are known to be associated with systemic connective tissue diseases or vasculitic diseases such as rheumatoid arthritis (RA), Wegener's granulomatosis, relapsing polychondritis, and systemic lupus erythematosus. The patients with scleritis in association with Behcet's disease (BD) have been rarely described in the literature. We report a 46-year-old female patient with BD who developed the nodular scleritis.

SJ-3366, a unique and highly potent nonnucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) that also inhibits HIV-2

We have identified and characterized a potent new nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1) that also is active against HIV-2 and which interferes with virus replication by two distinct mechanisms. 1-(3-Cyclopenten-1-yl)methyl-6-(3,5-dimethylbenzoyl)-5-ethyl-2,4-pyrimidinedione (SJ-3366) inhibits HIV-1 replication at concentrations of approximately 1 nM, with a therapeutic index of greater than 4 x 10(6). The efficacy and toxicity of SJ-3366 are consistent when evaluated with established or fresh human cells, and the compound is equipotent against all strains of HIV-1 evaluated, including syncytium-inducing, non-syncytium-inducing, monocyte/macrophage-tropic, and subtype virus strains. Distinct from other members of the pharmacologic class of NNRTIs, SJ-3366 inhibited laboratory and clinical strains of HIV-2 at a concentration of approximately 150 nM, yielding a therapeutic index of approximately 20,000. Like most NNRTIs, the compound was less active when challenged with HIV-1 strains possessing the Y181C, K103N, and Y188C amino acid changes in the RT and selected for a virus with a Y181C amino acid change in the RT after five tissue culture passages in the presence of the compound. In combination anti-HIV assays with nucleoside and nonnucleoside RT and protease inhibitors, additive interactions occurred with all compounds tested with the exception of dideoxyinosine, with which a synergistic interaction was found. Biochemically, SJ-3366 exhibited a K(i) value of 3.2 nM, with a mixed mechanism of inhibition against HIV-1 RT, but it did not inhibit HIV-2 RT. SJ-3366 also inhibited the entry of both HIV-1 and HIV-2 into target cells. On the basis of its therapeutic index and multiple mechanisms of anti-HIV action, SJ-3366 represents an exciting new compound for use in HIV-infected individuals.

Characterization of bacteriophage lambda excisionase mutants defective in DNA binding

The bacteriophage lambda excisionase (Xis) is a sequence-specific DNA binding protein required for excisive recombination. Xis binds cooperatively to two DNA sites arranged as direct repeats on the phage DNA. Efficient excision is achieved through a cooperative interaction between Xis and the host-encoded factor for inversion stimulation as well as a cooperative interaction between Xis and integrase. The secondary structure of the Xis protein was predicted to contain a typical amphipathic helix that spans residues 18 to 28. Several mutants, defective in promoting excision in vivo, were isolated with mutations at positions encoding polar amino acids in the putative helix (T. E. Numrych, R. I. Gumport, and J. F. Gardner, EMBO J. 11:3797-3806, 1992). We substituted alanines for the polar amino acids in this region. Mutant proteins with substitutions for polar amino acids in the amino-terminal region of the putative helix exhibited decreased excision in vivo and were defective in DNA binding. In addition, an alanine substitution at glutamic acid 40 also resulted in altered DNA binding. This indicates that the hydrophilic face of the alpha-helix and the region containing glutamic acid 40 may form the DNA binding surfaces of the Xis protein.

Detection of cryptic Y chromosome mosaicism by coamplification PCR with archived cytogenetic slides of suspected Turner syndrome

Turner syndrome is one of the most common cytogenetic abnormalities. It is known that the Y chromosome or Y derived material is present in 6-9% of TS patient and it may develop a high risk of gonadoblastoma in 15-25%. So it is crucial to carry out cyto genetic analysis and Y-specific probe studies for all persons with gonadal dysgenesis to rule out mosaicism with Y-bearing cell line; eg 45,X/46,XY. In this study, 26 archival slides previously analyzed cytogenetically as 45,X, 45,X/46,X,i(X), 45,X/46,X,r(X), and 45,X/46,XX were examined. Coamplification PCR, having the advantage of providing rapid result and confirming PCR failure, was performed with the slide samples in the regions of dystrophin gene in Xp21and DYZ3 in the Y centromeric region. All of archived slides were positive for X-specific gene and one slide of 45,X was found to have the cryptic Y chromosome material. Our result suggests that the archived cytogenetic slides could be applied for the detection of Y chromosome rapidly and efficiently in TS patients.

A case of coexisting Behçet's disease and ankylosing spondylitis

Behçet's disease (BD) is a chronic inflammatory condition involving several organs, such as skin, mucous membrane, eye, joint, intestine, lung and central nervous system. Ankylosing spondylitis (AS) is a prototype of seronegative spondyloarthropathy, and a chronic systemic inflammatory disorder of the axial skeleton, mainly affecting the sacroiliac joint and spine. In the latter, systemic complications may develop in addition to joint involvement. The coexistence of BD and AS has been rarely reported in the literature. The inclusion of BD among seronegative spondyloarthritides and whether sacroiliitis (SI) develops in BD are still being debated. We describe a 28-year-old man who has fulfilled the diagnostic criteria for BD and AS as well.

Site-specific recombination of bacteriophage P22 does not require integration host factor

Site-specific recombination by phages lambda and P22 is carried out by multiprotein-DNA complexes. Integration host factor (IHF) facilitates lambda site-specific recombination by inducing DNA bends necessary to form an active recombinogenic complex. Mutants lacking IHF are over 1,000-fold less proficient in supporting lambda site-specific recombination than wild-type cells. Although the attP region of P22 contains strong IHF binding sites, in vivo measurements of integration and excision frequencies showed that infecting P22 phages can perform site-specific recombination to its maximum efficiency in the absence of IHF. In addition, a plasmid integration assay showed that integrative recombination occurs equally well in wild-type and ihfA mutant cells. P22 integrative recombination is also efficient in Escherichia coli in the absence of functional IHF. These results suggest that nucleoprotein structures proficient for recombination can form in the absence of IHF or that another factor(s) can substitute for IHF in the formation of complexes.

An unusual type of cancer-associated retinopathy in a patient with ovarian cancer

We studied a case of unusual retinopathy in a 35-year-old woman who presented with bilateral visual deterioration due to retinal pigmentary mottling and serous elevation in the posterior pole. Two years before, she had undergone hysterectomy and bilateral salphingo-oophorectomy for ovarian cancer. Her electroretinogram became subnormal, and her fluorescein angiogram exhibited multiple deep retinal pigment epithelial leakages and subretinal dye pooling in both eyes. Corticosteroid therapy failed to prevent visual loss. She was found to possess antibodies against retinal 45 kd protein. This led to a diagnosis of cancer-associated retinopathy with atypical protein profile. We report a rare variety of cancer-associated retinopathy in a patient with-ovarian cancer.

Reactive cysteine residue of bovine brain glutamate dehydrogenase isoproteins

Protein chemical studies of glutamate dehydrogenase isoproteins (GDH I and GDH II) from bovine brain reveal that one cystein residue is accessible for reaction with thiol-modifying reagent. Reaction of the two types of GDH isoproteins with p-chloromercuribenzoic acid resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo first-order kinetics with the second-order rate constant of 83 M(-1) s(-1) and 75 M(-1) s(-1) for GDH I and GDH II, respectively. The inactivation was partially prevented by preincubation of the glutamate dehydrogenase isoproteins with NADH. A combination of 10 mM 2-oxoglutarate with 2 mM NADH gave complete protection against the inactivation. There were no significant differences between the two glutamate dehydrogenase isoproteins in their sensitivities to inactivation by p-chloromercuribenzoic indicating that the microenvironmental structures of the GDH isoproteins are very similar to each other. Allosteric effectors such as ADP and GTP had no effects on the inactivation of glutamate dehydrogenase isoproteins by thiol-modifying reagents. By a combination of peptide mapping analysis and labeling with [14C] p-chloromercuribenzoic acid, a reactive cystein residue was identified as Cys323 in the overall sequence. The cysteine residue was clearly identical to sequences of other GDH species known.