Impact of infectious complications after gastrectomy on non­gastric cancer­related deaths.

Infectious complications (ICs) have been reported as major causes of postoperative mortality in patients with cancer. However, to the best of our knowledge, the impact of ICs after gastrectomy on non-gastric cancer-related deaths (NGCDs) remains unexplored. The present study aimed to identify the impact of ICs after gastrectomy on NGCDs. A retrospective analysis of 712 patients with gastric cancer who underwent curative gastrectomy was conducted. The participants were categorized into IC and non-IC groups based on the incidence of postoperative IC. Clinicopathological factors and non-gastric cancer-related survival (NGCS) rates were compared between groups. Further NGCD and associated risk factor analyses were performed in a background factor-adjusted cohort using multivariate analysis. Among the 712 patients, 112 developed ICs (Clavien-Dindo classification grade ≥II). In the entire cohort, the IC group had a significantly worse 5-year cumulative incidence of NGCD (17.8 vs. 10.6%; Gray's P=0.021) compared with the non-IC group. Although a number of clinicopathological factors differed between the groups, including patient background, operative factors and tumor factors, the risk factors for NGCD identified in the multivariate analysis were older age, low prognostic nutritional index, low skeletal muscle index and Charlson comorbidity index ≥1, excluding IC incidents. The IC group exhibited more background factors contributing to NGCDs, suggesting a potential increase in NGCD regardless of IC incidence.

Chicken embryo cultures in the dorsal-upward orientation for the manipulation of epiblasts.

Chicken embryos have many advantages in the study of amniote embryonic development. In particular, culture techniques developed for early-stage embryos have promoted the advancement of modern developmental studies using chicken embryos. However, the standard technique involves placing chicken embryos in the ventral-upward (ventral-up) orientation, limiting manipulation of the epiblast at the dorsal surface, which is the primary source of ectodermal and mesodermal tissues. To circumvent this limitation, we developed chicken embryo cultures in the dorsal-up orientation and exploited this technique to address diverse issues. In this article, we first review the history of chicken embryo culture techniques to evaluate the advantages and limitations of the current standard technique. Then, the dorsal-up technique is discussed. These technological discussions are followed by three different examples of experimental analyses using dorsal-up cultures to illustrate their advantages: (1) EdU labeling of epiblast cells to assess potential variation in the cell proliferation rate; (2) migration behaviors of N1 enhancer-active epiblast cells revealed by tracking cells with focal fluorescent dye labeling in dorsal-up embryo culture; and (3) neural crest development of mouse neural stem cells in chicken embryos.

Safety and Feasibility of Neoadjuvant-Modified FOLFIRINOX in Elderly Patients with Pancreatic Cancer.

The optimal treatment strategy for neoadjuvant chemotherapy in elderly patients with pancreatic cancer (PC) remains unclear. Hence, this study was aimed at evaluating the safety and feasibility of neoadjuvant-modified FOLFIRINOX (mFOLFIRINOX) in elderly patients with PC. We retrospectively collected data from 62 patients who received neoadjuvant mFOLFIRINOX between May 2015 and October 2023 and comparatively analyzed the clinicopathological data and outcomes between the non-elderly group (age: <75 years) and elderly group (age: >75 years). The non-elderly and elderly groups comprised 39 and 23 patients, respectively. Although elevated levels of aspartate aminotransferase (p = 0.0173) and alanine aminotransferase (p = 0.0378) and nausea (p = 0.0177) were more frequent in the elderly group, the incidence of severe adverse events was similar between the groups. Intergroup differences in resection rate (p = 0.3381), postoperative severe complication rates (p = 0.2450), and postoperative hospital stay (p = 0.3496) were not significant. Furthermore, no significant intergroup differences were found in survival in either the whole or the resection cohorts. The perioperative and postoperative outcomes of elderly patients treated with neoadjuvant mFOLFIRINOX were comparable with those of non-elderly patients. Neoadjuvant mFOLFIRINOX should be considered a feasible option for elderly patients with PC.

Risk factors for infectious complications after gastrectomy in older patients.

The present study aimed to identify preoperative and perioperative risk factors for postoperative infectious complications in older patients with gastric cancer. The present retrospective study included 504 patients with gastric cancer aged >65 years who underwent radical gastrectomy. After determining the cutoff values for various perioperative factors in the receiver operating characteristic curve analysis, preoperative and perioperative risk factors for the development of infectious complications after gastrectomy were examined using logistic regression analysis. Of the 504 patients who underwent gastrectomy, 95 (18.8%) developed infectious complications of grade II-V based on the Clavien-Dindo classification. In an analysis restricted to preoperative factors, male sex, low prognostic nutritional index, high visceral fat area and total gastrectomy were independent risk factors for infectious complications after gastrectomy. Among all perioperative factors, a low prognostic nutritional index and long operative duration were identified as independent risk factors for infectious complications after gastrectomy. The patients were divided into five groups according to the number of positive preoperative risk factors for infectious complications, and the incidence of infectious complications differed among the five groups (0 factors, 6.7%; 1 factor, 10.4%; 2 factors, 18.9%; 3 factors, 27.8%; and 4 factors, 47.6%; P<0.001). Older patients with gastric cancer who have a number of preoperative risk factors require careful consideration of the indication for gastrectomy and a shorter operative time to reduce infectious complications.

Preventing Pneumonia in High-risk Patients After Esophageal Cancer Surgery: Mini-tracheostomy and Tazobactam/Piperacillin.

BACKGROUND/AIM: We evaluated the usefulness of prophylactic mini-tracheostomy (PMT) and perioperative administration of tazobactam/piperacillin (TAZ/PIPC) in high-risk patients after esophagectomy. PATIENTS AND METHODS: We retrospectively studied 89 consecutive high-risk patients who underwent esophagectomy for esophageal cancer between January 2013 and December 2021. We defined patients with two or more of the following factors as high risk: age ≥70 years, performance status ≥1, respiratory dysfunction, liver dysfunction, cardiac dysfunction, renal dysfunction, diabetes mellitus, albumin <3.5 g/dl, and Brinkman index >600. Standard management was administered to the first 50 patients (standard group). PMT and TAZ/PIPC were administered to the next 39 patients (combination group). Patient characteristics and short-term outcomes were compared before and after propensity-score matching. RESULTS: Before propensity-score matching, 24-hour urine creatinine clearance, retrosternal route, 3-field lymph node dissection, and open abdominal approach were more common, postoperative pneumonia (13% vs. 36%, p=0.045) and complications of grade ≥3b (2.6% vs. 22%, p=0.01) were less frequent, and the postoperative hospital stay was shorter (median: 23 vs. 28 days, p=0.022) in the combination group than in the standard group. In propensity-score matching, patient characteristics, except for 24-h creatinine clearance and reconstructive route, were matched for 23 paired patients. Postoperative pneumonia (8.7% vs. 39%, p=0.035) and complications of grade ≥3b (0% vs. 26%, p=0.022) were less frequent and postoperative hospital stay was shorter (median: 22 vs. 25 days, p=0.021) in the combination group than in the standard group. CONCLUSION: PMT with TAZ/PIPC can potentially prevent postoperative pneumonia in high-risk patients after esophagectomy.

Effects of Extended Fixation on Advanced Gastric Cancer HER2 Status Assessment Using IHC and FISH.

BACKGROUND/AIM: In gastric cancer, accurate determination of human epidermal growth factor receptor type 2 (HER2) status is crucial for treatment decision-making. However, the optimal formalin fixation time of gastric cancer specimens for HER2 status determination remains unestablished. Here, we investigated real-world data on formalin overfixation and its effect on HER2 status determination in gastric cancer. PATIENTS AND METHODS: We comprehensively analyzed HER2 testing results in 228 gastric cancer specimens, including those subjected to formalin overfixation. Subsequently, we divided 52 resected specimens of advanced gastric cancer into three groups and studied the effects of short-term (6-72 h) and long-term (1 and 2 weeks) fixation on HER2 status determination using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). RESULTS: A total of 21.5% (49/228) of the specimens were HER2-positive, whereas 78.5% (179/228) were negative. Among the HER2-negative specimens, no biopsies were overfixed, whereas 12.5% (9/72) of the surgical resection specimens were overfixed. The HER2 status of the 6-72-h group was 82.7% and 76.9% identical to that of the 1- and 2-week groups, when determined using IHC, and 73.1% and 36.5%, when determined using FISH, respectively. However, HER2 determination was not feasible in 26.9% and 63.5% of the specimens in the 1- and 2-week groups, respectively. CONCLUSION: Formalin overfixation may hinder the determination of HER2 status and should be avoided in gastric cancer sample preparation.

Steroid-resistant minimal change nephrotic syndrome associated with thymoma treated effectively with rituximab following thymectomy and cyclosporine: a case report.

BACKGROUND: Minimal change nephrotic syndrome (MCNS) can be complicated by thymoma; however, no standard therapy for thymoma-associated MCNS has yet been established. We herein describe a case of steroid-resistant MCNS associated with thymoma, treated effectively with rituximab. CASE PRESENTATION: A 71-year-old Japanese man was referred to our department with severe proteinuria (20 g/gCr). Renal biopsy showed minimal change disease and computed tomography revealed an anterior mediastinal mass. Based on these findings, he was diagnosed with thymoma-associated MCNS. He was treated with oral prednisolone (50 mg/day) and cyclosporine, and underwent thymectomy and plasma exchange. However, no improvement in proteinuria was observed. He therefore received intravenous rituximab 500 mg, resulting in a marked decrease in proteinuria from 5328 to 336 mg/day after 1 week. CONCLUSIONS: This case suggests that rituximab might be an effective therapy in patients with steroid-resistant MCNS associated with thymoma.

High serum proteinase-3 levels predict poor progression-free survival and lower efficacy of bevacizumab in metastatic colorectal cancer.

BACKGROUND: To improve the prognosis of patients with metastatic colorectal cancer (mCRC), investigating predictive biomarkers of their prognosis and chemotherapeutic responsiveness is necessary. This study aimed to analyze the clinical significance of serum proteinase-3 (PRTN3) as a predictor for prognosis and chemosensitivity, especially to bevacizumab therapy, in mCRC. METHODS: This single-center retrospective observational study enrolled 79 patients with mCRC in our hospital and 353 patients with colorectal cancer in the TCGA database. Preoperative serum PRTN3 levels were measured using an enzyme-linked immunosorbent assay. The clinicopathological characteristics and prognosis according to serum PRTN3 levels were then evaluated. PRTN3 expression in tumor and stromal cells was evaluated immunohistochemically. The impact of PRTN3 levels on angiogenesis and bevacizumab sensitivity was evaluated using the tube formation assay. RESULTS: Serum PRTN3 levels were an independent poor prognostic factor for progression-free survival (PFS) (hazard ratio, 2.082; 95% confidence interval, 1.118-3.647; P=0.010) in patients with mCRC. Similarly, prognostic analysis with TCGA data sets showed poorer overall survival in patients with PRTN3 expression than that in patients without PRTN3 expression, especially in patients with stage IV. Immunohistochemical analysis of resected specimens revealed that stromal neutrophils expressed PRTN3, and their expression level was significantly correlated with serum PRTN3 levels. Interestingly, the effectiveness of first-line chemotherapy was significantly poorer in the high serum PRTN3 level group. High serum PRTN3 was significantly associated with poor PFS (hazard ratio, 3.027; 95% confidence interval, 1.175-7.793; P=0.0161) in patients treated with bevacizumab, an anti-angiogenic inhibitor. The tube formation assay revealed that PRTN3 administration notably augmented angiogenesis while simultaneously attenuating the anti-angiogenic influence exerted by bevacizumab therapy. CONCLUSIONS: Serum PRTN3 levels could be a novel predictive biomarker of PFS of first-line chemotherapy, especially for bevacizumab therapy, in patients with mCRC.

A case of renal vein thrombosis associated with autoimmune hemolytic anemia and eosinophilic granulomatous polyangiitis.

Only a few cases of renal vein thrombosis (RVT) occurring in patients with vasculitis have been reported. RVT associated with vasculitis and hemolytic anemia has not been reported yet. We describe here a patient with RVT complicated by pulmonary embolism, autoimmune hemolytic anemia, and eosinophilic granulomatous polyangiitis. A 69-year-old Japanese man who had been treated with corticosteroids was referred to our department for severe proteinuria (4.32 g/gCr). Abdominal ultrasonography showed bilateral RVT, and contrast-enhanced computed tomography showed bilateral pulmonary embolism. Therefore, the patient was diagnosed with RVT complicated by pulmonary embolism. Anticoagulation therapy with heparin followed by apixaban was started. Thereafter, the D-dimer concentration decreased from 8.3 to 1.2 µg/mL, and urinary protein excretion improved to 0.62 g/gCr. Renal function was unchanged with an estimated glomerular filtration rate of 68.8 mL/minute/1.73 m2. The thrombi in both renal veins and pulmonary arteries gradually regressed. Clinicians should be aware of this complication when worsening proteinuria is observed during steroid therapy in patients with autoimmune hemolytic anemia and eosinophilic granulomatous polyangiitis.

IL-6 Levels Correlate with Prognosis and Immunosuppressive Stromal Cells in Patients with Colorectal Cancer.

BACKGROUND: The prognosis for patients with colorectal cancer (CRC) is determined by tumor characteristics as well as the host immune response. This study investigated the relationship between an immunosuppressive state and patient prognosis by evaluating the systemic and tumor microenvironment (TME) interleukin (IL)-6 levels. METHODS: Preoperative serum IL-6 levels were measured using an electrochemiluminescence assay. Expression of IL-6 in tumor and stromal cells was evaluated immunohistochemically in 209 patients with resected CRC. Single-cell analysis of tumor-infiltrating immune cells was performed using mass cytometry in 10 additional cases. RESULTS: Elevated serum IL-6 levels were associated with elevated stromal IL-6 levels and a poor prognosis for patients with CRC. High IL-6 expression in stromal cells was associated with low-density subsets of CD3+ and CD4+ T cells as well as FOXP3+ cells. Mass cytometry analysis showed that IL-6+ cells among tumor-infiltrating immune cells were composed primarily of myeloid cells and rarely of lymphoid cells. In the high-IL-6-expression group, the percentages of myeloid-derived suppressor cells (MDSCs) and CD4+FOXP3highCD45RA- effector regulatory T cells (eTreg) were significantly higher than in the low-IL-6-expression group. Furthermore, the proportion of IL-10+ cells in MDSCs and that of IL-10+ or CTLA-4+ cells in eTregs correlated with IL-6 levels. CONCLUSION: Elevated serum IL-6 levels were associated with stromal IL-6 levels in CRC. High IL-6 expression in tumor-infiltrating immune cells also was associated with accumulation of immunosuppressive cells in the TME.

Serum CCL7 Is a Novel Prognostic Biomarker of Metastatic Colorectal Cancer.

BACKGROUND/AIM: Colorectal cancer is the third most common cancer globally, and the poor prognosis of patients with metastatic colorectal cancer (mCRC) warrants urgent attention. We previously obtained 10 candidate serum biomarkers for mCRC. Our aim with this study was to determine the prognostic performance of the pre-treatment serum C-C motif chemokine ligand 7 (CCL7) concentration in patients with mCRC. PATIENTS AND METHODS: Protein concentrations of CCL7 were examined using ELISA and immunohistochemistry for serum (n=110) and surgical specimens (n=85), respectively, of patients with mCRC. The relationship between protein concentration and prognosis was examined using Cox regression analysis, receiver operator characteristic curve analysis and the Kaplan-Meier method. RESULTS: The overall survival (OS) of patients with high concentrations of serum CCL7 was significantly poorer than that of patients with low concentrations. Patients with a high CCL7 concentration in the stroma had significantly poorer outcomes than those with a low concentration. The concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 were significantly higher in the high-CCL7 group, compared to those in the low-CCL7 group. Univariate and multivariate analysis revealed that serum CCL7 concentration was a significant prognostic factor for mCRC. The combination of serum CCL and CEA concentrations was also useful in this regard (area under the curve=0.71). CONCLUSION: The combined pre-treatment serum levels of CCL7 and CEA are useful prognostic biomarkers for mCRC.

[A Severe Case of Bleeding from Duodenal Invasion Due to Co-Morbid IPMC with Arcuate Ligament Syndrome and IPDA Aneurysm].

An 81-year-old man with a history of left hemiplegia due to a cerebral hemorrhage was admitted to a clinic because of tarry stools. Endoscopic findings revealed an ulcerative lesion with hemorrhage in the descending duodenum. The patient was transferred to our hospital for treatment. Because endoscopic hemostasis was impossible, interventional radiology(IVR) hemostasis was performed using coil embolization for the feeding artery. Simultaneously, angiography showed stenosis of the root of the celiac axis due to arch ligament syndrome and an aneurysm of the inferior pancreaticoduodenal artery (IPDA). Due to the risk of rebleeding, subtotal stomach-preserving pancreatoduodenectomy was performed after the patient's overall condition had stabilized. Despite dissecting the arcuate ligament, the hepatic artery flow did not improve. Hence, a direct arterial anastomosis between the middle colic artery and the gastroduodenal artery was performed. Furthermore, due to the proximity of the IPDA aneurysm to the superior mesenteric artery, IVR embolization for the IPDA aneurysm was performed on postoperative day 8, and he was transferred to a rehabilitation hospital on postoperative day 57. The pathological result was invasive intraductal papillary mucinous carcinoma(IPMC). The patient has been an outpatient with no recurrence 12 months postoperatively.

Wnt signal-dependent antero-posterior specification of early-stage CNS primordia modeled in EpiSC-derived neural stem cells.

The specification of the embryonic central nervous system (CNS) into future brain (forebrain, midbrain, or hindbrain) and spinal cord (SC) regions is a critical step of CNS development. A previous chicken embryo study indicated that anterior epiblast cells marked by Sox2 N2 enhancer activity are specified to the respective brain regions during the transition phase of the epiblast to the neural plate-forming neural primordium. The present study showed that the SC precursors positioned posterior to the hindbrain precursors in the anterior epiblast migrated posteriorly in contrast to the anterior migration of brain precursors. The anteroposterior specification of the CNS precursors occurs at an analogous time (∼E7.5) in mouse embryos, in which an anterior-to-posterior incremental gradient of Wnt signal strength was observed. To examine the possible Wnt signal contribution to the anteroposterior CNS primordium specification, we utilized mouse epiblast stem cell (EpiSC)-derived neurogenesis in culture. EpiSCs maintained in an activin- and FGF2-containing medium start neural development after the removal of activin, following a day in a transitory state. We placed activin-free EpiSCs in EGF- and FGF2-containing medium to arrest neural development and expand the cells into neural stem cells (NSCs). Simultaneously, a Wnt antagonist or agonist was added to the culture, with the anticipation that different levels of Wnt signals would act on the transitory cells to specify CNS regionality; then, the Wnt-treated cells were expanded as NSCs. Gene expression profiles of six NSC lines were analyzed using microarrays and single-cell RNA-seq. The NSC lines demonstrated anteroposterior regional specification in response to increasing Wnt signal input levels: forebrain-midbrain-, hindbrain-, cervical SC-, and thoracic SC-like lines. The regional coverage of these NSC lines had a range; for instance, the XN1 line expressed Otx2 and En2, indicating midbrain characteristics, but additionally expressed the SC-characteristic Hoxa5. The ranges in the anteroposterior specification of neural primordia may be narrowed as neural development proceeds. The thoracic SC is presumably the posterior limit of the contribution by anterior epiblast-derived neural progenitors, as the characteristics of more posterior SC regions were not displayed.

Biological properties of Staphylococcus virus ΦSA012 for phage therapy.

Staphylococcus virus ΦSA012 has a wide host range and efficient lytic activity. Here, we assessed the biological stability of ΦSA012 against temperature, freeze-thawing, and pH to clinically apply the phage. In addition, inoculation of ΦSA012 through i.p. and i.v. injections into mice revealed that phages were reached the limit of detection in serum and accumulated notably spleens without inflammation at 48 h post-inoculation. Furthermore, inoculation of ΦSA012 through s.c. injections in mice significantly induced IgG, which possesses neutralizing activity against ΦSA012 and other Staphylococcus viruses, ΦSA039 and ΦMR003, but not Pseudomonas viruses ΦS12-3 and ΦR18 or Escherichia viruses T1, T4, and T7 in vitro. Immunoelectron microscopic analysis showed that purified anti-phage IgG recognizes the long-tail fiber of staphylococcus viruses. Although S. aureus inoculation resulted in a 25% survival rate in a mouse i.p. model, ΦSA012 inoculation (i.p.) improved the survival rate to 75%; however, the survival rate of ΦSA012-immunized mice decreased to less than non-immunized mice with phage i.v. injection at a MOI of 100. These results indicated that ΦSA012 possesses promise for use against staphylococcal infections but we should carefully address the appropriate dose and periods of phage administration. Our findings facilitate understandings of staphylococcus viruses for phage therapy.

Risk factors for non-gastric-cancer-related death after gastrectomy in elderly patients.

Aim: To identify preoperative factors, especially other diseases that cause death, that are associated with the prognosis of gastrectomy in elderly patients with gastric cancer. Methods: This retrospective study included a total of 211 consecutive patients aged ≥75 years who underwent radical gastrectomy due to gastric cancer. Time-dependent receiver operating characteristic curve analysis was performed to determine the optimal cutoff values for various perioperative factors. Risk factors for the overall survival and death from other diseases were analyzed using the Cox proportional hazards model. Results: Among the all perioperative factors, sex, neutrophil-to-lymphocyte ratio, skeletal muscle mass index, and lymph node dissection in accordance with guidelines or not extracted as independent risk factors for death from other diseases. In an analysis restricted to the preoperative factors, sex, neutrophil-to-lymphocyte ratio, and skeletal muscle mass index of the patients were extracted as independent risk factors for death from other diseases and overall survival. We divided the patients into four groups according to the number of preoperative risk factors for death from other diseases and found that the 5-year non-gastric-cancer-related survival was different among the four groups (risk factor 0, 91.7%; risk factor 1, 83.3%; risk factor 2, 56.3%; risk factor 3, 27.2%; P < 0.001). Conclusion: Male sex, low skeletal muscle mass index, and high neutrophil-to-lymphocyte ratio are risk factors for non-gastric-cancer-related death and the overall survival of elderly patients undergoing gastrectomy. Cautious treatment strategies are needed for elderly gastric cancer patients with many risk factors.

CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule.

BACKGROUND: We recently reported the relapse-free survival (RFS) significance of the combination of CD4+ and forkhead box P3+ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule. METHODS: Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence. RESULTS: Our study showed that the combination of low CD4+ and low FOXP3+ T-cell densities resulted in extremely poor RFS. CONCLUSIONS: Adjuvant chemotherapy may be considered for patients with a combination of low CD4+ and low FOXP3+ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

[Tumor Immunogenicity and Immune Checkpoint Inhibitors].

Cancer immunotherapy including immune checkpoint inhibitors(ICIs)have established itself as the fourth cancer therapy. However, the response rate of ICIs is still only about 20%, and tumors resistant to ICIs are often so-called"cold-tumor"with low tumor immunogenicity. Therefore, research and development is being conducted worldwide on how to convert cold- tumors into hot-tumors with high immunogenicity. In this paper, we review the relationship between tumor immunogenicity and ICI, as well as therapeutic methods to enhance tumor immunogenicity, and introduce our research about novel cancer peptide vaccination therapy.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells.

BACKGROUND: Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC. METHODS: Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA. RESULTS: RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13. CONCLUSION: The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

Live imaging of avian epiblast and anterior mesendoderm grafting reveals the complexity of cell dynamics during early brain development.

Despite previous intensive investigations on epiblast cell migration in avian embryos during primitive streak development before stage (st.) 4, this migration at later stages of brain development has remained uninvestigated. By live imaging of epiblast cells sparsely labeled with green fluorescence protein, we investigated anterior epiblast cell migration to form individual brain portions. Anterior epiblast cells from a broad area migrated collectively towards the head axis during st. 5-7 at a rate of 70-110 µm/h, changing directions from diagonal to parallel and forming the brain portions and abutting head ectoderm. This analysis revised the previously published head portion precursor map in anterior epiblasts at st. 4/5. Grafting outside the brain precursor region of mCherry-expressing nodes producing anterior mesendoderm (AME) or isolated AME tissues elicited new cell migration towards ectopic AME tissues. These locally convergent cells developed into secondary brains with portions that depended on the ectopic AME position in the anterior epiblast. Thus, anterior epiblast cells are bipotent for brain/head ectoderm development with given brain portion specificities. A brain portion potential map is proposed, also accounting for previous observations.