Totally laparoscopic versus laparoscopy-assisted distal gastrectomy: the KLASS-07, a randomized controlled trial.

BACKGROUNDS: Strong evidence is lacking as no confirmatory randomized controlled trials (RCTs) have compared the efficacy of totally laparoscopic distal gastrectomy (TLDG) with laparoscopy-assisted distal gastrectomy (LADG). We performed an RCT to confirm if TLDG is different from LADG. METHODS: The XXXXX trial is a multicentre, open-label, parallel-group, phase III, RCT of 442 patients with clinical stage I gastric cancer. Patients were enrolled from 21 cancer care centers in South Korea between January 2018 and September 2020 and randomized to undergo TLDG or LADG using blocked randomization with a 1:1 allocation ratio, stratified by the participating investigators. Patients were treated through R0 resections by TLDG or LADG as the full analysis set of the XXXXX trial. The primary endpoint was morbidity within postoperative day 30, and the secondary endpoint was QoL for 1 year. This trial is registered at ClinicalTrials.gov (NCT XXXXXXXX). RESULTS: 442 patients were randomized (222 to TLDG, 220 to LADG), and 422 patients were included in the pure analysis (213 and 209, respectively). The overall complication rate did not differ between the two groups (TLDG vs. LADG: 12.2% vs. 17.2%). However, TLDG provided less postoperative ileus and pulmonary complications than LADG (0.9% vs. 5.7%, P=0.006; and 0.5% vs. 4.3%, P=0.035, respectively). The QoL was better after TLDG than after LADG regarding emotional functioning at 6 months, pain at 3 months, anxiety at 3 and 6 months, and body image at 3 and 6 months (all P<0.05). However, these QoL differences were resolved at 1 year. CONCLUSIONS: The XXXXX trial confirmed that TLDG is not different from LADG in terms of postoperative complication but has advantages to reduce ileus and pulmonary complications. TLDG can be a good option to offer better QoL in terms of pain, body image, emotion, and anxiety at 3-6 months.

Development of PET Radioisotope Copper-64-Labeled Theranostic Immunoliposomes for EGFR Overexpressing Cancer-Targeted Therapy and Imaging.

Combining standard surgical procedures with personalized chemotherapy and the continuous monitoring of cancer progression is necessary for effective NSCLC treatment. In this study, we developed liposomal nanoparticles as theranostic agents capable of simultaneous therapy for and imaging of target cancer cells. Copper-64 (64Cu), with a clinically practical half-life (t1/2 = 12.7 h) and decay properties, was selected as the radioisotope for molecular PET imaging. An anti-epidermal growth factor receptor (anti-EGFR) antibody was used to achieve target-specific delivery. Simultaneously, the chemotherapeutic agent doxorubicin (Dox) was encapsulated within the liposomes using a pH-gradient method. The conjugates of 64Cu-labeled and anti-EGFR antibody-conjugated micelles were inserted into the doxorubicin-encapsulating liposomes via a post-insertion procedure (64Cu-Dox-immunoliposomes). We evaluated the size and zeta-potential of the liposomes and analyzed target-specific cell binding and cytotoxicity in EGFR-positive cell lines. Then, we analyzed the specific therapeutic effect and PET imaging of the 64Cu-Dox-immunoliposomes with the A549 xenograft mouse model. In vivo therapeutic experiments on the mouse models demonstrated that the doxorubicin-containing 64Cu-immunoliposomes effectively inhibited tumor growth. Moreover, the 64Cu-immunoliposomes provided superior in vivo PET images of the tumors compared to the untargeted liposomes. We suggest that nanoparticles will be the potential platform for cancer treatment as a widely applicable theranostic system.

Reappraisal of optimal reconstruction after distal gastrectomy - a study based on the KLASS-07 database.

BACKGROUNDS: This study aimed to compare the incidence of bile reflux, quality of life (QoL), and nutritional status among Billroth II (BII), Billroth II with Braun anastomosis (BII-B), and Roux-en-Y (RY) reconstruction after laparoscopic distal gastrectomy (LDG). MATERIALS AND METHODS: We reviewed the prospective data of 397 patients from a multicentre database who underwent LDG for gastric cancer between 2018 and 2020 at 20 tertiary teaching hospitals in Korea. Postoperative endoscopic findings, QoL surveys using the European Organization for Research and Treatment of Cancer questionnaire (C30 and STO22), and nutritional and surgical outcomes were compared among groups. RESULTS: In endoscopic findings, bile reflux was the lowest in the RY group ( n =67), followed by the BII-B ( n =183) and BII groups ( n =147) at 1 year (3.0 vs. 67.8 vs. 84.4%, all P <0.05). The anti-reflux capability of BII-B was statistically better than that of BII, but not as perfect as that of RY. From the perspective of QoL, BII-B was not inferior to RY, but better than BII reconstruction in causing fewer STO22 reflux symptoms at 6 and 12 months. However, only RY caused fewer C30 nausea symptoms than BII at 6 and 12 months, but not BII-B. Nutritional status and morbidities were similar among the three groups, and the operative time did not differ between the BII-B and RY groups. CONCLUSIONS: BII-B cannot substitute for RY in preventing bile reflux, shortening the operative time, or reducing morbidities. Regarding short-term QoL, BII-B was sufficient to reduce STO22 reflux symptoms but failed to reduce C30 nausea symptoms postoperatively.

E3 ligase SOCS3 regulates NOD2 expression by ubiquitin proteasome system in lung cancer progression.

PURPOSE: Despite lung cancer is one of the leading causes of cancer-related deaths, it remains hard to discover effective diagnostic and therapeutic approaches. Moreover, the five-year survival rate is relatively lower than other tumors. So urgent needs for finding a new theranostic target to treat lung cancer effectively. This study aims to present SOCS3 and NOD2 proteins as novel targets for diagnosis and therapy. METHODS: We first confirmed SOCS3 expression level in patients' tissues. Then, we applied knockdown and overexpression of SOCS3 on lung cancer cell lines and performed proliferation, migration, and invasion assay. After that, we found NOD2 is a target of SOCS3 and introduced overexpression of NOD2 to A549 for verifying reduced tumorigenicity of lung cancer cells. RESULTS: We identified protein expression level of SOCS3 was frequently higher in tumor tissues than adjacent normal tissues. Truly, overexpression of SOCS3 promoted proliferation, migration, and invasion capacity of lung cancer cells. We found that SOCS3 interacts with NOD2 and SOCS3 ubiquitinates NOD2 directly. Furthermore, lung cancer tissues with higher SOCS3 expression showed lower NOD2 expression. We confirmed overexpression of NOD2 leads to suppressed tumorigenicity of lung cancer cells, and these effects occurred through MAPK pathway. CONCLUSION: Collectively, our work reveals novel roles of SOCS3 in lung tumorigenesis and proposes SOCS3 as a promising biomarker candidate for therapeutic and diagnostic target for lung cancer.

Elevated expression of Axin2 in intestinal metaplasia and gastric cancers.

BACKGROUND: The Wnt signaling pathway regulates crucial cellular processes, including stem cell development and tissue repair. Dysregulation of this pathway, particularly ß-catenin stabilization, is linked to colorectal carcinoma and other tumors. Axin2, a critical component in the pathway, plays a role in ß-catenin regulation. This study examines Axin2 expression in normal gastric mucosa and various gastric pathologies. METHODS: Formalin-fixed and paraffin-embedded tissue samples from normal stomach, gastritis, intestinal metaplasia (IM), and gastric carcinoma were collected. Axin2 and ß-catenin expression were evaluated using RNA in situ hybridization and immunohistochemistry, respectively. Histo-scores (H-scores) were calculated to quantify expression levels of Axin2. Associations between Axin2 expression and clinicopathological variables were examined. RESULTS: Axin2 expression was examined in normal stomach, gastritis, and IM tissues. Axin2 expression was mainly observed in the surface and isthmus areas in the normal stomach and gastritis, whereas Axin2 expression was markedly higher at the bases of IM. Axin2 H-scores were significantly elevated in IM (mean ± standard deviation [SD], 87.0 ± 38.9) compared to normal (mean ± SD, 18.0 ± 4.5) and gastritis tissues (mean ± SD, 33.0 ± 18.6). In total, 30% of gastric carcinomas showed higher Axin2 expression. Axin2 expression did not have significant associations with age, sex, Lauren classification, histological differentiation, invasion depth, and lymph node metastasis. However, a strong positive correlation was observed between Axin2 and nuclear ß-catenin in gastric carcinomas (p < .001). CONCLUSIONS: Axin2 expression was significantly increased in IM compared to normal and gastritis cases. In addition, Axin2 showed a strong positive association with nuclear ß-catenin expression in gastric carcinomas, demonstrating a close relationship with abnormal Wnt/ß-catenin signaling pathway.

Effects of UBE3A on Cell and Liver Metabolism through the Ubiquitination of PDHA1 and ACAT1.

Nonalcoholic fatty liver disease (NAFLD) is substantiated by the reprogramming of liver metabolic pathways that disrupts the homeostasis of lipid and glucose metabolism and thus promotes the progression of the disease. The metabolic pathways associated with NAFLD are regulated at different levels from gene transcription to various post-translational modifications including ubiquitination. Here, we used a novel orthogonal ubiquitin transfer platform to identify pyruvate dehydrogenase A1 (PDHA1) and acetyl-CoA acetyltransferase 1 (ACAT1), two important enzymes that regulate glycolysis and ketogenesis, as substrates of E3 ubiquitin ligase UBE3A/E6AP. We found that overexpression of UBE3A accelerated the degradation of PDHA1 and promoted glycolytic activities in HEK293 cells. Furthermore, a high-fat diet suppressed the expression of UBE3A in the mouse liver, which was associated with increased ACAT1 protein levels, while forced expression of UBE3A in the mouse liver resulted in decreased ACAT1 protein contents. As a result, the mice with forced expression of UBE3A in the liver exhibited enhanced accumulation of triglycerides, cholesterol, and ketone bodies. These results reveal the role of UBE3A in NAFLD development by inducing the degradation of ACAT1 in the liver and promoting lipid storage. Overall, our work uncovers an important mechanism underlying the regulation of glycolysis and lipid metabolism through UBE3A-mediated ubiquitination of PDHA1 and ACAT1 to regulate their stabilities and enzymatic activities in the cell.

Suppression of Lung Cancer Malignancy by Micellized siRNA through Cell Cycle Arrest.

UBA6-specific E2 conjugation enzyme 1 (USE1) is frequently overexpressed in lung cancer patients. Moreover, the critical role of USE1 in the progression of human lung cancer is also indicated. As the next step, the authors aim to develop USE1-targeted therapeutic agents based on RNA interference (RNAi). In this study, a lipid-modified DNA carrier, namely U4T, which consists of four consecutive dodec-1-ynyluracil (U) nucleobases to increase the cell permeability of siRNA targeting of USE1 is introduced. The U4Ts aggregate to form micelles, and the USE1-silencing siRNA-incorporated soft spherical nucleic acid aggregate (siSNA) can be created simply through base-pairing with siRNA. Treatment with siSNA is effective in suppressing tumor growth in vivo as well as cell proliferation, migration, and invasion of lung cancer cells. Furthermore, siSNA inhibited tumor cell growth by inducing cell cycle arrest in the G1 phase and apoptosis. Thus, the anti-tumor efficacy of siSNA in lung cancer cell lines and that siSNA possesses effective cell-penetrating ability without using cationic transfection moieties are confirmed. Collectively, these results suggest that siSNA can be applied to the clinical application of RNAi-based therapeutics for lung cancer treatment.

Microcurvature Controllable Metal-Organic Framework Nanoagents Capable of Ice-Lattice Matching for Cellular Cryopreservation.

Ice-binding proteins (IBPs) produced by psychrophilic organisms to adapt for the survival of psychrophiles in subzero conditions have received illustrious interest as a cryopreservation agent required for cells and tissues to completely recover after freezing/thawing. Depressing water-freezing point and avoiding ice-crystal growth affect their activities which are closely related to the presence of ice crystal well-matched binding moiety. The interaction of IBPs with ice and water is critical in enhancing their freeze avoidance against cell or tissue damage. Metal-organic frameworks (MOFs) with a controllable lattice at the molecular level and a size at the nanometer scale can offer periodically ordered ice-binding sites by modifying organic linkers and controlling microcurvature at the ice surface. Herein, zirconium (Zr)-based MOF-801 nanoparticles (NPs) with good biocompatibility were used as a cryoprotectant that is well dispersed and colloidal-stable in an aqueous solution. The MOF NP size was precisely controlled, and 10, 35, 100, and 250 nm NPs were prepared. The specific IBPs-mimicking pendants (valine and threonine) were simply introduced into the MOF NP-surface through the acrylate-based functionalization to endow with hydrophilic and hydrophobic dualities. When small-sized MOF-801 NPs were attached to ice, they confined ice growth in high curvature between the adsorption sites because of the decreased radius of the convex area of the growth region, leading to highly enhanced ice recrystallization inhibition (IRI). Surface-functionalized MOF NPs could increase the number of anchored clathrate water molecules with hydrophilic/hydrophobic balance of the ice-binding moiety, effectively inhibiting ice growth. The MOF-801 NPs were biocompatible with various cell lines regardless of concentration or NP surface-functionalization, whereas the smaller-sized surface-functionalized NPs showed a good cell recovery rate after freezing/thawing by induction of IRI. This study provides a strategy for the fabrication of low-cost, high-volume antifreeze nanoagents that can extend useful applications to organ transplantation, cord blood storage, and vaccines/drugs.

Inhibition of the Ubiquitin Transfer Cascade by a Peptidomimetic Foldamer Mimicking the E2 N-Terminal Helix.

The enzymatic cascades for ubiquitin transfer regulate key cellular processes and are the intense focus of drug development for treating cancer and neurodegenerative diseases. E1 is at the apex of the UB transfer cascade, and molecules inhibiting E1 have shown promising activities against cancer cell proliferation. Compared to small molecules, peptidomimetics have emerged as powerful tools to disrupt the protein-protein interactions (PPI) with less drug resistance and high stability in the cell. Herein, we harnessed the D-sulfono-γ-AA peptide to mimic the N-terminal helix of E2 and thereby inhibit E1-E2 interaction. Two stapled peptidomimetics, M1-S1 and M1-S2, were identified as effective inhibitors to block UB transfer from E1 to E2, as shown by in vitro and cellular assays. Our work suggested that PPIs with the N-terminal helix of E2 at the E1-E2 and E2-E3 interfaces could be a promising target for designing inhibitors against protein ubiquitination pathways in the cell.

Structural studies of antitumor compounds that target the RING domain of MDM2.

Mouse double minute 2 homolog (MDM2) is an E3 ubiquitin-protein ligase that is involved in the transfer of ubiquitin to p53 and other protein substrates. The expression of MDM2 is elevated in cancer cells and inhibitors of MDM2 showed potent anticancer activities. Many inhibitors target the p53 binding domain of MDM2. However, inhibitors such as Inulanolide A and MA242 are found to bind the RING domain of MDM2 to block ubiquitin transfer. In this report, crystal structures of MDM2 RING domain in complex with Inulanolide A and MA242 were solved. These inhibitors primarily bind in a hydrophobic site centered at the sidechain of Tyr489 at the C-terminus of MDM2 RING domain. The C-terminus of MDM2 RING domain, especially residue Tyr489, is required for ubiquitin discharge induced by MDM2. The binding of these inhibitors at Tyr489 may interrupt interactions between the MDM2 RING domain and the E2-Ubiquitin complex to inhibit ubiquitin transfer, regardless of what the substrate is. Our results suggest a new mechanism of inhibition of MDM2 E3 activity for a broad spectrum of substrates.

EGF Receptor-Targeting Cancer Therapy Using CD47-Engineered Cell-Derived Nanoplatforms.

Introduction: Avoiding phagocytic cells and reducing off-target toxicity are the primary hurdles in the clinical application of nanoparticles containing therapeutics. For overcoming these errors, in this study, nanoparticles expressing CD47 proteins inhibiting the phagocytic attack of immune cells were prepared and then evaluated as an anti-cancer drug delivery vehicle. Methods: The CD47+ cell-derived nanoparticles (CDNs) were prepared from the plasma membranes of human embryonic kidney cells transfected with a plasmid encoding CD47. And the doxorubicin (DOX) was loaded into the CDNs, and anti-EGF receptor (EGFR) antibodies were conjugated to the surface of the CDNs to target tumors overexpressing EGFR. Results: The CD47+iCDNs-DOX was successfully synthesized having a stable structure. The CD47+CDNs were taken up less by RAW264.7 macrophages compared to control CDNs. Anti-EGFR CD47+CDNs (iCDNs) selectively recognized EGFR-positive MDA-MB-231 cells in vitro and accumulated more effectively in the target tumor xenografts in mice. Moreover, iCDNs encapsulating doxorubicin (iCDNs-DOX) exhibited the highest suppression of tumor growth in mice, presumably due to the enhanced DOX delivery to tumor tissues, compared to non-targeting CDNs or CD47- iCDNs. Discussion: These results suggest that the clinical application of biocompatible cell membrane-derived nanocarriers could be facilitated by functionalization with macrophage-avoiding CD47 and tumor-targeting antibodies.

Long-Term Survival Outcomes of Elderly Patients Treated With S-1 or Capecitabine Plus Oxaliplatin for Stage II or III Gastric Cancer: A Multicenter Cohort Study.

Purpose: Tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) are standard adjuvant chemotherapies (ACs) administered after gastrectomy to patients with stage II or III gastric cancer. However, the efficacy of AC in elderly patients remains unclear. The objective of this retrospective multicenter cohort study was to compare the efficacies of S-1 and CAPOX AC in patients aged ≥70 years. Materials and Methods: Nine hundred eighty-three patients who were treated with AC using S-1 (768 patients) or CAPOX (215 patients) were enrolled in this study. Each patient underwent AC after curative gastrectomy for stage II or III gastric cancer at one of 27 hospitals in the Republic of Korea between January 2012 and December 2013. Relapse-free survival (RFS) and overall survival (OS) were analyzed according to AC regimen and age group. Results: Of the 983 patients, 254 (25.8%) were elderly. This group had a similar RFS (P=0.099) but significantly poorer OS (p=0.003) compared with the non-elderly group. Subgroup analysis of the non-elderly group revealed no AC-associated differences in survival. Subgroup analysis of the elderly group revealed significantly better survival in the S-1 group than in the CAPOX group (RFS, P<0.001; OS, P<0.001). Multivariate analysis revealed that the CAPOX regimen was an independent poor prognostic factor for RFS (hazard ratio [HR], 1.891; 95% confidence interval [CI], 1.072-3.333; P=0.028) and OS (HR, 2.970; 95% CI, 1.550-5.692; P=0.001). Conclusions: This multicenter observational cohort study found significant differences in RFS and OS between S-1 and CAPOX AC among patients with gastric cancer aged ≥70 years.

EPHB2 expression is associated with intestinal phenotype of gastric cancer and indicates better prognosis by suppressing gastric cancer migration.

The protein tyrosine kinase Ephrin type-B receptor 2 (EPHB2) belongs to one of the intestinal stem cell signature genes and plays a crucial role in maintaining the crypt-villous axis. Herein, we aimed to investigate the expression of EPHB2 during gastric carcinogenesis and evaluated its prognostic and functional significance in gastric cancer (GC). EPHB2 expression was upregulated in intestinal metaplasia and GCs compared to normal antral and fundic glands. EPHB2 mRNA levels were strongly correlated with the intestinal stem cell markers OLFM4, LGR5, and EPHB3. Notably, EPHB2 expression was significantly correlated with CDX2 expression, and in vitro studies demonstrated that CDX2 expression increased both EPHB2 transcription and protein levels. In a large cohort of GC patients, EPHB2 positivity was observed in 39% of 704 GCs and was negatively correlated with tumor differentiation, lymphovascular invasion, and tumor-node-metastasis stages. Notably, EPHB2 positivity was associated with better overall survival, and it was an independent prognostic marker in intestinal-type GCs. Overexpression of EPHB2 in GC cell lines, MKN-28 and MKN-74, reduced migration activity by suppressing phosphorylation of focal adhesion kinase, whereas no significant difference was observed in proliferation rates. Thus, we suggest that EPHB2 acts as a tumor suppressor in GCs and can be a prognostic marker in intestinal-type GCs.

Activation of E6AP/UBE3A-Mediated Protein Ubiquitination and Degradation Pathways by a Cyclic γ-AA Peptide.

Manipulating the activities of E3 ubiquitin ligases with chemical ligands holds promise for correcting E3 malfunctions and repurposing the E3s for induced protein degradation in the cell. Herein, we report an alternative strategy to proteolysis-targeting chimeras (PROTACs) and molecular glues to induce protein degradation by constructing and screening a γ-AA peptide library for cyclic peptidomimetics binding to the HECT domain of E6AP, an E3 ubiquitinating p53 coerced by the human papillomavirus and regulating pathways implicated in neurodevelopmental disorders such as Angelman syndrome. We found that a γ-AA peptide P6, discovered from the affinity-based screening with the E6AP HECT domain, can significantly stimulate the ubiquitin ligase activity of E6AP to ubiquitinate its substrate proteins UbxD8, HHR23A, and ß-catenin in reconstituted reactions and HEK293T cells. Furthermore, P6 can accelerate the degradation of E6AP substrates in the cell by enhancing the catalytic activities of E6AP. Our work demonstrates the feasibility of using synthetic ligands to stimulate E3 activities in the cell. The E3 stimulators could be developed alongside E3 inhibitors and substrate recruiters such as PROTACs and molecular glues to leverage the full potential of protein ubiquitination pathways for drug development.

Individual Differences in Colour Perception: The Role of Low-Saturated and Complementary Colours in Ambiguous Images.

Individual differences in colour perception, as evidenced by the popular debate of "The Dress" picture, have garnered additional interest with the popularisation of additional, similar photographs. We investigated which colorimetric characteristics were responsible for individual differences in colour perception. All objects of the controversial photographs are composed of two representative colours, which are low in saturation and are either complementary to each other or reminiscent of complementary colours. Due to these colorimetric characteristics, we suggest that one of the two complementary pixel clusters should be estimated as the illuminant hue depending on assumed brightness. Thus, people perceive the object's colours as being biased toward complementarily different colour directions and perceive different pixel clusters as chromatic and achromatic. Even though the distance between colours that people perceive differently is small in colour space, people perceive the object's colour as differently categorized colours in these ambiguous photographs, thereby causing debate. We suggest that people perceive the object's colours using different "modes of colour appearance" between surface-colour and self-luminous modes.

Expression profile of intestinal stem cell and cancer stem cell markers in gastric cancers with submucosal invasion.

Cancer stem cells (CSCs) are believed to be responsible for tumor growth, invasion, and metastasis. Submucosal invasion, which greatly enhances metastasis risk, is a critical step in gastric cancer (GC) progression. To identify stem cell-related markers associated with submucosal invasion and lymph node (LN) metastasis in GCs, we investigated the expression of candidate CSC markers (CD133, CD44, and ALDH1A) and intestinal stem cell (ISC) markers (EPHB2, OLFM4, and LGR5) in early GCs that manifested submucosal invasion. We discovered that EPHB2 and LGR5 expression was frequently confined to the basal area of the lamina propria (basal pattern) in mucosal cancer, and the proportion of stem cell marker-positive cells substantially increased during submucosal invasion. CD44 expression showed a focal pattern, ALDH1A was predominantly expressed diffusely, and there was no expansion of CD44 or ALDH1A expression in the submucosal cancer cells. Unexpectedly, no CSC markers showed any associations with LN metastasis, and only loss of EPHB2 expression was associated with increased LN metastasis. Treatment of RSPO2, a niche factor, along with Wnt 3a, to GC cells led to increased EPHB2 and LGR5 mRNA levels. RNA in situ hybridization confirmed specific RSPO2 expression in the smooth muscle cells of the muscularis mucosa, suggesting that RSPO2 is responsible for the increased expression of ISC markers in GC cells at the basal areas. In summary, no stem cell markers were associated with increased LN metastasis in early GCs. Conversely, isolated EPHB2 expression was associated with lower LN metastasis. EPHB2 and LGR5 showed a basal distribution pattern along with enhanced expression in submucosal invading cells in early GCs, which was induced by a niche factor, RSPO2, from the muscularis mucosa.

Appropriate Number of Adjuvant Chemotherapy Cycles for Patients with Stage 2 or 3 Gastric Cancer After Curative Gastrectomy: A Multicenter Cohort Study.

BACKGROUND: Few studies have presented evidence pertaining to the adequate minimum number of adjuvant chemotherapy (AC) cycles required to achieve an oncologic benefit for gastric cancer. METHODS: From January 2012 to December 2013, data from patients who underwent curative radical gastrectomy and consequently received AC for pathologic stage 2 or 3 gastric cancer at 27 institutions in South Korea were analyzed. RESULTS: The study enrolled 925 patients, 661 patients (71.5%) who completed 8 cycles of AC and 264 patients (28.5%) who did not. Compared with the mean disease-free survival (DFS) of the patients who completed 8 AC cycles (69.3 months), the mean DFS of patients who completed 6 AC cycles (72.4 months; p = 0.531) and those who completed 7 AC cycles (63.7 months; p = 0.184) did not differ significantly. However, the mean DFS of the patients who completed 5 AC cycles (48.2 months; p = 0.016) and those who completed 1-4 AC cycles (62.9 months; p = 0.036) was significantly lower than the DFS of those who completed 8 AC cycles. In the multivariate Cox proportional hazards analysis, the mean DFS was significantly affected by advanced stage, large tumor size, positive vascular invasion, and number of completed AC cycles (1-5 cycles: hazard ratio 1.45; 95% confidence interval 1.01-2.08; p = 0.041). CONCLUSION: The current multicenter observational cohort study showed that the mean DFS for 6 or 7 AC cycles was similar to that for 8 AC cycles as an adjuvant treatment for gastric cancer.

Long-term Efficacy of S-1 Monotherapy or Capecitabine Plus Oxaliplatin as Adjuvant Chemotherapy for Patients with Stage II or III Gastric Cancer after Curative Gastrectomy: a Propensity Score-Matched Multicenter Cohort Study.

PURPOSE: To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC). MATERIALS AND METHODS: This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively. RESULTS: The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693-4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664-1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595-85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502-5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618-3.028; P<0.001) were determined as independent prognostic factors for DFS. CONCLUSIONS: S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence.

BRC-mediated RNAi targeting of USE1 inhibits tumor growth in vitro and in vivo.

USE1 has been demonstrated to play crucial roles in the development and progression of human lung cancer. However, the antitumor efficacy of RNA interference (RNAi) targeting of USE1 has not yet been evaluated as a possible clinical application. We here synthesized USE1 targeting bubbled RNA-based cargo (BRC) composed of densely packed multimeric pre-siRNAs with specific Dicer cleavage sites to enable efficient siRNA release upon entry to target cells. The physical entanglement and continuous networking of RNAs via hybridization during enzymatic replication serve as a driving force for the self-assembly of BRCs. These molecules effectively suppressed the transcription of their target genes, leading to tumor growth suppression in vitro and in vivo. Moreover, their repeated intravenous administration efficiently inhibited the growth of A549 tumor xenografts. Based on these findings of a reduced cancer cell viability following a USE1 knockdown, we further explored cell cycle arrest and apoptosis pathways. The observed tumor cell growth suppression was found to be controlled by cell cycle arrest and apoptosis signals induced by the USE1 reduction. These results suggest that USE1 BRCs may have future clinical applications as an RNAi-based cancer therapy.

USP14 Inhibition Regulates Tumorigenesis by Inducing Autophagy in Lung Cancer In Vitro.

The ubiquitin-proteasome system is an essential regulator of several cellular pathways involving oncogenes. Deubiquitination negatively regulates target proteins or substrates linked to both hereditary and sporadic forms of cancer. The deubiquitinating enzyme ubiquitin-specific protease 14 (USP14) is associated with proteasomes where it trims the ubiquitin chain on the substrate. Here, we found that USP14 is highly expressed in patients with lung cancer. We also demonstrated that USP14 inhibitors (IU1-47 and siRNA-USP14) significantly decreased cell proliferation, migration, and invasion in lung cancer. Remarkably, we found that USP14 negatively regulates lung tumorigenesis not only through apoptosis but also through the autophagy pathway. Our findings suggest that USP14 plays a crucial role in lung tumorigenesis and that USP14 inhibitors are potent drugs in lung cancer treatment.