Hirokatsu Katagiri

A Distinct Subpopulation of Bone Marrow Mesenchymal Stem Cells, Muse Cells, Directly Commit to the Replacement of Liver Components.

Genotyping graft livers by short tandem repeats after human living‐donor liver transplantation (n = 20) revealed the presence of recipient or chimeric genotype cases in hepatocytes (6 of 17, 35.3%), sinusoidal cells (18 of 18, 100%), cholangiocytes (15 of 17, 88.2%) and cells in the periportal areas (7 of 8, 87.5%), suggesting extrahepatic cell involvement in liver regeneration. Regarding extrahepatic origin, bone marrow mesenchymal stem cells (BM‐MSCs) have been suggested to contribute to liver regeneration but compose a heterogeneous population. We focused on a more specific subpopulation (1–2% of BM‐MSCs), called multilineage‐differentiating stress‐enduring (Muse) cells, for their ability to differentiate into liver‐lineage cells and repair tissue. We generated a physical partial hepatectomy model in immunodeficient mice and injected green fluorescent protein (GFP)‐labeled human BM‐MSC Muse cells intravenously (n = 20). Immunohistochemistry, fluorescence in situ hybridization and species‐specific polymerase chain reaction revealed that they integrated into regenerating areas and expressed liver progenitor markers during the early phase and then differentiated spontaneously into major liver components, including hepatocytes (≈74.3% of GFP‐positive integrated Muse cells), cholangiocytes (≈17.7%), sinusoidal endothelial cells (≈2.0%), and Kupffer cells (≈6.0%). In contrast, the remaining cells in the BM‐MSCs were not detected in the liver for up to 4 weeks. These results suggest that Muse cells are the predominant population of BM‐MSCs that are capable of replacing major liver components during liver regeneration.

Long-term outcomes of laparoscopic versus open liver resection for liver metastases from colorectal cancer: A comparative analysis of 168 consecutive cases at a single center

BACKGROUND Laparoscopic liver resection for liver metastases from colorectal cancer (CRLM) is performed in a relatively small number of institutions. Its operative results have been reported to be comparable with that of open laparotomy; however, information on its oncologic outcomes is scarce. This study aimed to compare the long-term outcomes of laparoscopic hepatectomy (LH) and open hepatectomy (OH) to treat CRLM at a single institution. METHODS We retrospectively reviewed data from 168 consecutive patients who underwent LH (n = 100) or OH (n = 68) for CRLM. The tumor characteristics, operative results, overall survival (OS) rate, recurrence-free survival (RFS) rate, and recurrence patterns were analyzed and compared. A previously published survival-predicting nomogram was applied to compare OS and RFS between the 2 patient groups. RESULTS The largest tumor diameter and the number of tumors were significantly larger in the OH group than in the LH group; however, no differences in other tumor factors were observed between the 2 groups. When matched by the nomogram, OS and RFS remained comparable between the 2 groups in every examined stratum, not only for low-risk patients but also for those with high risk. The recurrence patterns also were similar (liver: 30.2% vs 26.8%, P = .72; lung: 22.6% vs 34.1%, P = .22; peritoneum: 7.6% vs 4.9%, P = .45). CONCLUSION The long-term outcomes of laparoscopic liver resection for CRLM were comparable with those of the open procedure in not only low-risk but also high-risk patients.

Contrasting expression patterns of histone mRNA and microRNA 760 in patients with gastric cancer

Purpose: Recent studies revealed that both disseminated tumor cells and noncancerous cells contributed to cancer progression cooperatively in the bone marrow. Here, RNA-seq analysis of bone marrow from gastric cancer patients was performed to identify prognostic markers for gastric cancer. Experimental Design: Bone marrow samples from eight gastric cancer patients (stages I and IV: n = 4 each) were used for RNA-seq analysis. Results were validated through quantitative real-time PCR (qRT-PCR) analysis of HIST1H3D expression in 175 bone marrow, 92 peripheral blood, and 115 primary tumor samples from gastric cancer patients. miR-760 expression was assayed using qRT-PCR in 105 bone marrow and 96 primary tumor samples. Luciferase reporter assays were performed to confirm whether histone mRNAs were direct targets of miR-760. miR-760 expression was also evaluated in noncancerous cells from gastric cancer patients. Results: RNA-seq analysis of bone marrow samples from gastric cancer patients revealed higher expression of multiple histone mRNAs in stage IV patients. HIST1H3D expression in the bone marrow, peripheral blood, and primary tumor of stage IV patients was higher than that in stage I patients (P = 0.0284, 0.0243, and 0.0006, respectively). In contrast, miR-760 was downregulated in the bone marrow and primary tumor of stage IV patients compared with stage I patients (P = 0.0094 and 0.0018, respectively). Histone mRNA and miR-760 interacted directly. Furthermore, miR-760 was downregulated in noncancerous mucosa in stage IV gastric cancer patients. Conclusion: Histone mRNA was upregulated, whereas miR-760 was downregulated in the bone marrow and primary tumor of advanced gastric cancer patients, suggesting that the histone mRNA/miR-760 axis had a crucial role in the development of gastric cancer. Clin Cancer Res; 19(23); 6438–49. ©2013 AACR.

A compensatory role of NF-κB to p53 in response to 5-FU-based chemotherapy for gastric cancer cell lines.

Despite of remarkable improvement of postoperative 5-FU–based adjuvant chemotherapy, the relapse rate of gastric cancer patients who undergo curative resection followed by the adjuvant chemotherapy remains substantial. Therefore, it is important to identify prediction markers for the chemotherapeutic efficacy of 5-FU. We recently identified NF-κB as a candidate relapse prediction biomarker in gastric cancer. To evaluate the biological significance of NF-κB in the context of 5-FU–based chemotherapy, we analyzed the NF-κB-dependent biological response upon 5-FU treatment in gastric cancer cell lines. Seven genes induced by 5-FU treatment in an NF-κB-dependent manner were identified, five of which are known p53 targets. Knockdown of RELA, which encodes the p65 subunit of NF-κB, decreased both p53 and p53 target protein levels. In contrast, NF-κB was not affected by TP53 knockdown. We also demonstrated that cell lines bearing Pro/Pro homozygosity in codon72 of p53 exon4, which is important for NF-κB binding to p53, are more resistant to 5-FU than those with Arg/Arg homozygosity. We conclude that NF-κB plays an important role in the response to 5-FU treatment in gastric cancer cell lines, with a possible compensatory function of p53. These results suggest that NF-κB is a potential 5-FU-chemosensitivity prediction marker that may reflect 5-FU-induced stress-response pathways, including p53.

Molecular marker identification for relapse prediction in 5-FU-based adjuvant chemotherapy in gastric and colorectal cancers.

To confirm the clinical significance of NF-κB and JNK protein expression from experimentally identified candidates for predicting prognosis for patients with 5-FU treatment, we evaluated the protein expression of surgically removed specimens. A total of 79 specimens were obtained from 30 gastric and 49 colorectal cancer patients who underwent R0 resection followed by postoperative 5-FU based adjuvant chemotherapy. Immunohistochemical examinations of NF-κB and JNK on tissue microarrays (TMAs) revealed that significantly shorter time-to-relapse (TTR) in both NF-κB(+) and JNK(−) subgroups in both gastric (NF-κB(+), p = 0.0002, HR11.7. 95%CI3 3.2–43.4; JNK(−), p = 0.0302, HR4.4, 95%CI 1.2–16.6) and colon (NF-κB(+), p = 0.0038, HR36.9, 95%CI 3.2–426.0; JNK(−), p = 0.0098, HR3.2, 95%CI 1.3–7.7) cancers. These protein expression patterns also show strong discriminately power in gastric cancer patients for overall survival rate, suggesting a potential utility as prognostic or chemosensitivity markers. Baseline expression of these proteins using gastric cancer cell lines demonstrated the reciprocal patterns between NF-κB and JNK, while 5-FU exposure of these cell lines only induced NF-κB, suggesting that NF-κB plays a dominant role in the response to 5-FU. Subsequent siRNA experiments confirmed that gene knockdown of NF-κB increased 5-FU-specific sensitivity, whereas that of JNK did not affect the chemosensitivity. These results suggest that the expression of these proteins may aid in the decisions involved with adjuvant chemotherapy for gastrointestinal tract cancers.

The first comparative study of the perioperative outcomes between pure laparoscopic donor hepatectomy and laparoscopy-assisted donor hepatectomy in a single institution

Background In a statement from the second International Consensus Conference for Laparoscopic Liver Resection, adult-to-adult laparoscopic donor surgery was the earliest phase of development. It was recommended that the procedure be performed under institutional ethical approval and a reporting registry. Method At our institute, we started laparoscopy-assisted donor hepatectomy (LADH) in 2007 and changed to pure laparoscopic donor hepatectomy (PLDH) in 2012. This study included 40 living donors who underwent LADH and 14 live donors who underwent PLDH. We describe the technical aspects and outcomes of our donor hepatectomy from assist to pure and examine the liver allograft outcomes of the recipients after LADH and PLDH. Results There was significantly less blood loss in the PLDH group (81.07 ± 52.78 g) than that in the LADH group (238.50 ± 177.05 g), although the operative time was significantly longer in the PLDH group (454.93 ± 85.60 minutes) than in the LADH group (380.40 ± 44.08 minutes). And there were no significant differences in postoperative complication rate in the 2 groups. The liver allograft outcomes were acceptable and comparable with open living donor hepatectomy. Conclusions By changing our routine approach from assist to pure, PLDH can be performed safely, with better exposure due to magnification, and with less blood loss under pneumoperitoneal pressure. PLDH, which has become our promising donor procedure, results in less blood loss, better cosmesis, and the donor’s complete rehabilitation without deterioration in donor safety.

A novel model for prediction of pure laparoscopic liver resection surgical difficulty

BackgroundExtending the clinical indications for laparoscopic liver resection (LLR) should be carefully considered based on a surgeon’s experience and skill. However, objective indexes to help surgeons assess the estimated difficulty of LLR are scarce. The aim of our study was to develop the first objective numerical rating scale to predict the surgical difficulty of various LLR procedures.MethodsWe performed a retrospective review of the operative outcomes of 187 patients who underwent a pure LLR. First, the value of preoperative factors for predicting surgical time was evaluated by multivariate linear regression analyses, and a scoring system was constructed. Next, the integrity of our predictive linear model was evaluated against the documented operative outcomes for patients forming our study group.ResultsFour predictive factors were identified and scored based on the weighted contribution of each factor predicting surgical time: extent of resection (scored 0, 2, or 3); location of tumor (scored 0, 1, or 2); obesity (scored 0 or 1); and platelet count (scored 0 or 1). The scores were summed to classify surgical difficulty into three levels: low (total score ≤1); medium (total score 2–3); and high (total score ≥4). Operative outcomes, including surgical time, volume of blood loss, length of hospital stay, and rate of morbidity, were significantly different between the three surgical difficulty levels.ConclusionOur novel model will be useful for surgeons to predict the difficulty of an LLR procedure relative to their own experience and skill.

Laparoscopic liver resection for hepatocellular carcinoma with cirrhosis in a single institution

BACKGROUND In a statement by the second International Consensus Conference for Laparoscopic Liver Resection (LLR), minor LLR was confirmed to be a standard surgical practice, as it has become adopted by an increasing proportion of surgeons. However, it is unclear whether this applies to the more complex group of patients suffering from cirrhosis. Therefore, the aim of this retrospective study was to compare the feasibility and safety of LLR for hepatocellular carcinoma (HCC) between non-liver cirrhosis (NLC) patients and liver cirrhosis (LC) patients at a single high-volume laparoscopy center. METHODS From the beginning of 2000 to the end of 2013, open liver resection (OLR) was performed in 99 HCC patients, and LLR was in 118. The HCC patients who underwent LLR were divided into NLC-LLR (n=60) and LC-LLR (n=58) groups, and we compare the short-term outcomes between them. RESULTS There was no significant difference in the incidence of blood loss and transfusion requirements between the NLC-LLR group and the LC-LLR group, although wedge resection was mainly performed in the LC-LLR group. There was no significant difference in the complication rate between the two groups, and the remarkable finding was that there was a significantly lower incidence of postoperative ascites in the LC-LLR group than in the NLC-LLR group. CONCLUSIONS According to our experience, it appears that LLR for selected HCC patients with cirrhosis is a feasible and promising procedure that is associated with less blood loss and fewer postoperative complications, especially the incidence of postoperative ascites. Further investigations are clearly warranted.

α-Amanitin Restrains Cancer Relapse from Drug-Tolerant Cell Subpopulations via TAF15.

Cancer relapse occurs with substantial frequency even after treatment with curative intent. Here we studied drug-tolerant colonies (DTCs), which are subpopulations of cancer cells that survive in the presence of drugs. Proteomic characterization of DTCs identified stemness- and epithelial-dominant subpopulations, but functional screening suggested that DTC formation was regulated at the transcriptional level independent from protein expression patterns. We consistently found that α-amanitin, an RNA polymerase II (RNAPII) inhibitor, effectively inhibited DTCs by suppressing TAF15 expression, which binds to RNA to modulate transcription and RNA processing. Sequential administration of α-amanitin and cisplatin extended overall survival in a cancer-relapse mouse model, namely peritonitis carcinomatosa. Therefore, post-treatment cancer relapse may occur through non-distinct subpopulations and may be effectively prevented by α-amanitin to disrupt transcriptional machinery, including TAF15.

Evaluation of chemosensitivity prediction using quantitative dose–response curve classification for highly advanced/relapsed gastric cancer

BackgroundThe use of standard chemotherapy regimens has changed the application of chemosensitivity tests from all chemotherapy-eligible patients to those who have failed standard chemotherapy, which includes patients with highly advanced, relapsed, or chemoresistant tumors.MethodsWe evaluated a total of 43 advanced primary and relapsed gastric cancers for chemosensitivity based on drug dose response curves to improve the objectivity and quality of quantitative measurements. The dose response curves were classified based on seven expected patterns. Instead of a binary chemosensitivity evaluation, we ranked drug sensitivity according to curve shapes and comparison with the peak plasma concentration (ppc) of each drug.ResultsA total of 193 dose response curves were obtained. The overall informative rate was 67.4%, and 85.3% for cases that had a sufficient number of cells. Paclitaxel (PXL)and docetaxel tended to show a higher rank, while cisplatin (CIS) and 5-fluorouracil (5-FU) tended to show resistance, particularly among the 20 cases (46.5%) that had recurrent disease after receiving chemotherapy with CIS and S-1 (5-FU). As such, we speculate that the resistant pattern of the chemosensitivity test suggests that cells with acquired drug resistance were selected by chemotherapy. Indeed, we observed a change in the chemosensitivity pattern of a sample before and after chemotherapy in terms of PXL sensitivity, which was used after primary chemotherapy.ConclusionsThese results suggest that: (i) the dose–response pattern provides objective information for predicting chemosensitivity; and (ii) chemotherapy may select resistant cancer cell populations as a result of the therapy.