Background:Lung cancer is the leading cause of cancer-related death worldwide, of which anaplastic lymphoma kinase fusion positive (ALK +) non-small cell lung cancer (NSCLC) accounts for 3-7. Here, we identified a new fusion gene PLCXD3-ALK (P1, A19) from a patient with advanced lung squamous cell carcinoma (LUSC) by next-generation sequencing (NGS). We aimed to evaluate its oncogenic potential by performing functional studies in vitro and tumorigenicity in vivo of this fusion protein. Methods:We performed functional experiments in NIH-3T3 cells with stable expression of PLCXD3-ALK including soft agar colony formation assay, cell proliferation and viability assays, and transwell assay. The activation of downstream pathways and the response to ALK inhibitors crizotinib and alectinib were demonstrated by western blotting (WB). In addition, we further evaluated the tumorigenicity of the PLCXD3-ALK mutants in nude mice. Results:Similar to EML4-ALK, the PLCXD3-ALK fusion promoted proliferation and the capacity for non-anchorage-dependent growth of NIH-3T3 cells. We demonstrated that PLCXD3-ALK can activate ALK self-phosphorylation and downstream pathways, which could be inhibited by the addition of ALK inhibitors. Moreover, we observed that this gene could provoke oncogenic transformation in nude mice. Meanwhile, the patient was monitored for disease progression with computed tomography (CT) scanning during treatment with alectinib, and a benefit was observed. Conclusions:We identified and functionally validated PLCXD3-ALK as a novel rare fusion in NSCLC that has not been previously reported. It can serve as a meaningful therapeutic target for ALK inhibitors of ALK + NSCLC.

Aims/Background Hepatitis B virus (HBV) infection poses a challenge to global healthcare. Peginterferon alfa-2b (PEG-IFNα-2b) is an effective treatment for HBV infection. This study aimed to explore the efficacy of PEG-IFNα-2b combined with entecavir in the treatment of HBV infection, its effect on liver function and immune factors, and the risk factors affecting the prognosis of patients with HBV infection. Methods The clinical data of 184 patients with HBV infection who were treated at Jinhua Central Hospital from January 2021 to January 2024 were collected for retrospective analysis. Patients were divided into a control group (not receiving antiviral treatment, n = 34), a standard treatment group (receiving entecavir, n = 85), and a combination treatment group (PEG-IFNα-2b and entecavir, n = 65) according to the treatment approach. Treatment efficacy, liver function indicators (albumin [ALB], alanine aminotransferase [ALT], and aspartate aminotransferase [AST]), immune factor indexes (tumour necrosis factor alpha [TNF-α] and interferon gamma [IFN-γ]), hepatitis B surface antigen [HBsAg] and HBV DNA levels were compared among the three groups. All patients were followed up after treatment. According to their prognosis, the patients were divided into good prognosis group (n = 118) and poor prognosis group (n = 66). Logistic regression analysis was performed to explore the risk factors affecting the prognosis of HBV patients. Results The efficacy in the combination treatment group was higher (92.31%) than that in the control group (8.82%) and the standard treatment group (78.82%) (p < 0.05). After treatment, the HBsAg and HBV DNA levels were decreased in the standard treatment and combination treatment groups (p < 0.05). Compared with the control and standard treatment groups, the combination treatment group exhibited significantly lower HBsAg and HBV DNA levels after treatment (p < 0.05). Besides, the combination treatment group had lower ALT and AST levels (p < 0.05), and higher ALB level (p < 0.05), than the control and standard treatment groups after treatment. Compared with the control and standard treatment groups, the combination treatment group demonstrated decreased TNF-α level and higher IFN-γ level after treatment (p < 0.05). Multivariate logistic regression analysis identified family medical history as the risk factor affecting the prognosis of patients with HBV infection (p = 0.001, odds ratio [OR] = 3.614, 95% confidence interval [CI]: 1.685–7.750) and therapy regimen as the protective factor (p = 0.029, OR = 0.135, 95% CI: 0.022–0.815). Conclusion The PEG-IFNα-2b combination therapy in patients with HBV infection significantly improves the clinical treatment efficacy, liver function, and immune factors. In addition, this study found that therapy regimen and family medical history are independent factors affecting the prognosis of HBV infection.

Elevated infiltration of tumor-associated macrophages (TAMs) drives tumor progression and correlates with poor prognosis for various tumor types. Our research identifies that the ablation of the Pim-1 proto-oncogene (PIM1) in non-small cell lung cancer (NSCLC) suppresses TAM infiltration and prevents them from polarizing toward the M2 phenotype, thereby reshaping the tumor immune microenvironment (TME). The predominant mechanism through which PIM1 exerts its impact on macrophage chemotaxis and polarization involves CC motif chemokine ligand 2 (CCL2). The expression level of PIM1 is positively correlated with high CCL2 expression in NSCLC, conferring a worse overall patient survival. Mechanistically, PIM1 deficiency facilitates the reprogramming of TAMs by targeting nuclear factor kappa beta (NF-κB) signaling and inhibits CCL2 transactivation by NSCLC cells. The decreased secretion of CCL2 impedes TAM accumulation and their polarization toward a pro-tumoral phenotype. Furthermore, Dual blockade of Pim1 and PD-1 collaboratively suppressed tumor growth, repolarized macrophages, and boosted the efficacy of anti-PD-1 antibody. Collectively, our findings elucidate the pivotal role of PIM1 in orchestrating TAMs within the TME of NSCLC and highlight the potential of PIM1 inhibition as a strategy for enhancing the efficacy of cancer immunotherapy.

Background: Tumor cell inhibition is a pivotal focus in anti-cancer research, and extensive investigations have been conducted regarding the role of p53. Numerous studies have highlighted its close association with reactive oxygen species (ROS). However, the precise impact of the antioxidant glutathione (GSH) in this context remains inadequately elucidated. Here, we will elucidate the anti-cancer mechanisms mediated by p53 following treatment with GSH. Methods: In this study, we employed a p53 gene knockout approach in SW480 colorectal cells and conducted comprehensive analyses of 20 amino acids and proteomics using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Results: These analyses unveiled profound alterations in amino acids and proteins triggered by GSH treatment, shedding light on novel phenomena and delineating the intricate interplay between GSH and cellular proteins. The deletion of the p53 gene exerts a profound influence on tumor cell proliferation. Moreover, tumor cell proliferation is significantly affected by elevated GSH levels. Importantly, in the absence of the p53 gene, cells exhibit heightened sensitivity to GSH, leading to inhibited cell growth. The combined therapeutic approach involving GSH and p53 gene deletion expedites the demise of tumor cells. It is noteworthy that this treatment leads to a marked decline in amino acid metabolism, particularly affecting the down-regulation of methionine (Met) and phenylalanine (Phe) amino acids. Among the 41 proteins displaying significant changes, 8 exhibit consistent alterations, with 5 experiencing decreased levels and 3 demonstrating increased quantities. These proteins primarily participate in crucial cellular metabolic processes and immune functions. Conclusions: In conclusion, the concurrent administration of GSH treatment and p53 gene deletion triggers substantial modifications in the amino acid and protein metabolism of tumor cells, primarily characterized by down-regulation. This, in turn, compromises cell metabolic activity and immune function, ultimately culminating in the demise of tumor cells. These newfound insights hold promising implications and could pave the way for the development of straightforward and efficacious anti-cancer treatments.

Acquired resistance is inevitable in the treatment of non-small cell lung cancer (NSCLC) with osimertinib, and one of the primary mechanisms responsible for this resistance is the epithelial-mesenchymal transition (EMT). We identify upregulation of the proviral integration site for Moloney murine leukemia virus 1 (PIM1) and functional inactivation of glycogen synthase kinase 3β (GSK3β) as drivers of EMT-associated osimertinib resistance. Upregulation of PIM1 promotes the growth, invasion, and resistance of osimertinib-resistant cells and is significantly correlated with EMT molecules expression. Functionally, PIM1 suppresses the ubiquitin-proteasome degradation of snail family transcriptional repressor 1 (SNAIL) and snail family transcriptional repressor 2 (SLUG) by deactivating GSK3β through phosphorylation. The stability and accumulation of SNAIL and SLUG facilitate EMT and encourage osimertinib resistance. Furthermore, treatment with PIM1 inhibitors prevents EMT progression and re-sensitizes osimertinib-resistant NSCLC cells to osimertinib. PIM1/GSK3β signaling is activated in clinical samples of osimertinib-resistant NSCLC, and dual epidermal growth factor receptor (EGFR)/PIM1 blockade synergistically reverse osimertinib-resistant NSCLC in vivo. These data identify PIM1 as a driver of EMT-associated osimertinib-resistant NSCLC cells and predict that PIM1 inhibitors and osimertinib combination therapy will provide clinical benefit in patients with EGFR-mutant NSCLC.

Background: The number of lymph nodes examined (LNe) is often insufficient in patients with rectal cancer (RC) treated with neoadjuvant therapy; however, its prognostic value remains controversial. Thus, we retrospectively explored whether LNe had an influence on staging and prognosis and investigated whether there was a cut-off value for better prognosis in patients with RC treated with neoadjuvant therapy. Methods: Data were collected from seven prospective hospital databases in China from July 2002 to May 2018. Binary logistic regression models were used to predict lymph node metastasis. The cut-off value for LNe was determined using X-tile 3.6.1. Survival outcomes and risk factors were analyzed using the log-rank test and Cox regression model. Results: A total of 482 patients were included, of whom 459 had complete overall survival (OS) information. Using the percentile method, the total number of lymph nodes examined (TLNe) was 14-16 (40th-60th percentile), and the proportion of patients with lymph node metastasis reached a maximum of 48.1%. Cox multivariate analysis showed that the odds ratio (OR) remained the highest when TLNe was 14-16 (OR = 3.379, P = 0.003). The 3-year and 5-year OS were 85.4% and 77.8%, respectively. Negative lymph nodes examined (NLNe) of <6 was an independent risk factor for 3-year and 5-year OS (3-year OS 71.1% vs. 85.9%, P = 0.004; 5-year OS 66.3% vs. 74.3%, P = 0.035). Subgroup analysis for patients with ypN + showed that higher 3-year and 5-year OS were achieved when the TLNe was >10, 78.8% vs. 54.0% (P = 0.005), and 60.8% vs. 36.0% (P = 0.012), respectively. Patients with ypN0M0 had a higher 5-year OS when the TLNe was >19 (P = 0.055). Conclusion: The TLNe and NLNe influenced the staging accuracy and demonstrated prognostic value in patients with RC treated with neoadjuvant therapy.

目的 比较评估微信平台结合PBL模式与传统教学模式在胃肠外科教学中的差异.方法 选取2020届北京大学医学部八年制胃肠外科临床见习学生62名,时间为2016年9月—2016年12月,随机分为传统教学对照组31名及微信平台结合PBL模式教学试验组31名,教学后发放问卷进行满意度调查,同时进行胃肠外科理论考试和技能考试,比较两组教学效果.结果 试验组学生的胃肠外科理论考试成绩和临床技能考核成绩均高于对照组,且组间差异均有统计学意义(P<0.05);试验组学生对带教模式认可度较对照组高,且差异有统计学意义(P<0.05).结论 微信平台结合PBL模式在胃肠外科教学较传统模式效果更好,满意度更高.

Objective:To investigate clinicopathological characteristics and efficacy of conversion therapy in patients with metastatic gastric cancer.Methods:The clinicopathological and follow-up data of metastatic gastric cancer patients at the Department of Gastrointestinal Surgery of Peking University People's Hospital from Jan 2018 to Jun 2021 were retrospectively studied. Multivariate Logistic regression analysis was used to identify independent characteristics for pathological complete response (PCR). The influence of stage of metastatic gastric cancer and pathological response on prognosis were analyzed by Kaplan-Meier curve.Results:A total of 31 patients were enrolled, and 13 tumors located at the cardia or fundus, 8 at body, other 10 at pylorus or antrum . Baseline CT evaluation showed retroperitoneal lymph node metastasis in 10 cases, intraperitoneal metastasis in 10 cases, liver metastasis in 2 cases, adrenal and splenic metastasis in 1 case respectively, and multiple metastasis in 5 cases. After conversion therapy, 8 (26%) cases had pathological T0, 16 cases (52%) had pathological N0 and 7 cases (22%) had pathological complete response. Multivariate Logistic regression analysis showed retroperitoneal lymph node metastasis ( OR: 20.082, 95% CI: 2.141-188.315, P=0.009) was the only independent risk factor of PCR. Meanwhile, Kaplan-Meier curve showed pT0 improved disease-free survival significantly ( P=0.021). Conclusions:Metastatic gastric cancer patients with retroperitoneal lymph node metastasis alone had a tolerable conversion therapy effect. pT0 is a significant factor in improving prognosis.

Objective:to study the mutation of p53 gene in colorectal cancer, analyze the relationship between p53 gene mutation and numb expression pattern, and explore its clinicopathological significance in colorectal cancer.Methods:p53 gene mutation in 60 colorectal cancer tissues was analyzed by polymerase chain reaction (PCR) and DNA sequencing, and the expression of numb protein was detected by Western blot. The colon cancer cell lines HCT116 (+), HCT116 (-) and flow cytometry were used. The survival curve was drawn by Kaplan Meier method.Results:p53 gene mutation was found in 31 of 60 tissues (52%), and the mutation times of exons (E) 5, 6, 7 and 8 were 5, 6, 12 and 11 respectively. The expression level of numb in p53 mutation group was significantly lower than that in non mutation group ( P=0.009). The prognosis of patients with low expression of numb (39 cases) was worse than that of high expression of numb (21 cases) ( P=0.015). Its expression level is closely related to the degree of differentiation, lymph node metastasis and TNM stage (all P<0.05). After the two cell lines were transferred into numb, the cell cycle appeared G2-M phase arrest and proliferation was inhibited, while dapt had G1-S phase arrest. Conclusion:p53 gene mutation related to the expression of numb in colon cancer, which has significant effect on the prognosis.

普通外科学是临床学科的重要分支，也是所以外科学的基础?从外总到相关学科的疾病，内容复杂，涉及全身各个系统，对医学生来说，如何从基础到临床掌握好这一门学科至关重要，而从教师教学层面来说，如何把普通外科学教学体系优化则是一个重要的研究方向，本文学科的特点入手，分析外科学如何整合基础学科?教学方式?临床技能培养?人文关怀能力培养等多方面进行系统阐述，为外科学教学提供一些有益的思路?

BACKGROUND Previous studies on how complete mesocolic excision (CME) affects prognosis indicate fundamental limitations that prevent the procedure from being completely accepted in practice. This study evaluated 5-year survival in colon cancer patients who underwent CME in a strict quality-controlled trial. STUDY DESIGN A prospective, nonrandomized, double-blind, controlled trial recruited patients who underwent open radical resection for colon cancer between November 2012 and November 2017. Third-party experts evaluated whether patients had undergone mesocolic dissection and/or central ligation by looking at photographs of both surgical field and specimen, and then divided patients into CME and non-CME (NCME) groups. The primary outcome was the 5-year local recurrence-free survival rate. Clinicopathological and follow-up data were recorded. RESULTS There were 261 patients with a median follow-up time of 57 months assigned to the CME group, and 129 patients with a median follow-up time of 59 months were assigned to the NCME group. The 5-year local recurrence-free survival rate of patients with Union Internationale Contre le Cancer stage I to III cancer did not differ significantly between the groups. For stage I to III cancer and stage III cancer, the absolute risk reduction of 5-year cumulative death and disease progression after CME were 9.1% (95% CI 1% to 17%; p = 0.033) and 16.1% (95% CI 1% to 31%; p = 0.040), respectively. Meanwhile, CME also could reduce 14% 5-year cumulative incidence recurrence for Union Internationale Contre le Cancer stage III cancer compared with NCME (CME, 27.3% vs NCME, 41.3%; p = 0.042) after adjusting for the effect of non-cancer-related death. CONCLUSIONS CME should be considered as a standard surgical procedure in affected patients.

胃肠道肿瘤外科教学是临床外科教学的重要章节，MDT多学科诊疗模式是目前肿瘤诊治的最合理模式，本文从胃肠肿瘤综合治疗背景为切入点，阐述了该科目教学的过程特点、重点以及如何与MDT模式相结合，使医生对患者做出的临床决策更加符合患者利益诉求，同时使我们对医学生的教学规范，培养其全程管理的理念，也谈一点儿自己思考与体会，为胃肠外科教学提供一些借鉴及方法。

Objective:To study the status of numb methylation and p53 gene mutation in colorectal cancer tissues, and to analyze the relationship between p53 mutation and numb/Notch1 expression pattern.Methods:Methylation specific PCR (MSP) was used to detect the methylation status of the promoter region of numb gene. Polymerase chain reaction (PCR) and DNA sequencing were used to analyze the mutation of p53. The expression of numb in 60 cases of colorectal cancer was detected by blot. The correlation between p53 mutation status and numb expression level, the relationship between the expression pattern of p53 and clinicopathological parameters of colorectal cancer, and the relationship between the expression of numb and the survival of patients were studied.Results:Compared with normal intestinal mucosa, 25 (41.7%) colorectal cancer tissues showed partial methylation of numb gene promoter, but there was no correlation between numb gene promoter methylation and mRNA and protein expression ( P>0.05). P53 gene mutation was found in 31 of 60 patients, with the mutation rate of 51.7%, and exon (E) 5, 6, 7, 8 The number of mutations in exons E7 and E8 was 5, 6, 12 and 11 (including 2 exons E7 and E8 mutations in 2 cases, and exon E5 and E8 in 1 case). The expression level of numb in p53 mutation group was significantly lower than that in non mutation group ( P<0.05) (see table 2.5). There was a negative linear correlation between p53 mutation and numb protein expression, with a correlation coefficient of -0.69. There was a positive linear correlation between p53 mutation and Notch1 protein expression (correlation coefficient was 0.33), but there was no significant correlation between p53 mutation and delta and Jagged1 protein expression. The prognosis of patients with low expression of numb (39 cases) was worse than that of patients with high expression of numb (21 cases) ( P<0.05), and the difference was statistically significant ( P<0.05). Conclusion:p53 mutation status is closely related to numb expression level, which can be used as a new reference index for some biological behaviors and prognosis of colorectal cancer.

胃肠道肿瘤外科学是临床外科教学的重要内容,是普通外科学的桥梁课程,涉及外科总论、胃肠道常见疾病的诊断与治疗等,临床带教水平直接影响大外科的教学效果.因此,本文从胃肠肿瘤综合治疗背景为切入点,阐述了胃肠肿瘤的临床特点、教学要点、诊治重点;同时归纳总结了如何在信息化背景下优化胃肠外科教学模式、教与学如何有机结合等内容,通过教学临床实践浅谈思考与体会,为完善胃肠外科教学体系、优化教学途径提供参考.

Objective:To investigate the effect of microRNA (miRNA, miR)-195 on the expression of Delta-like ligand 4 (Dll4), a ligand of Notch pathway, in colorectal cancer (CRC).Methods:From November 2010 to February 2011, 56 patients with CRC underwent radical resection in our department. MiRNA microarray was used to screen the differential expression of miR-195 in CRC tissues from 6 cases and normal intestinal mucosa tissues. Real-time quantitative polymerase chain reaction (PCR) was used to detect the relative expression of miR-195. Western blotting was used to detect the expression of miR-195. The expression of Dll4 protein in Notch pathway was detected in 56 cases of CRC tissues and adjacent normal intestinal mucosa. The interaction and activity of miR-195 and Dll4 3′untranslated regions (3′UTR) region were detected by double luciferase reporter gene assay. Colon cancer cell line SW480 was treated with miR-195 (40 pmol/L), and its effect on cell apoptosis was observed by flow cytometry. The expression of Dll4, Jagged1, intracellular domain of notch (NICD), Cyclin D1, Hes1, B cell lymphoma/leukemia-2 (bcl-2) and nuclear factor-κB (NF-κB) was detected by Western blotting.Results:The expression level of miR-195 was significantly lower [0.34 times (0.341±0.008)], and that of Dll4 was significantly higher [1.92 times (1.922±0.003)] in CRC tissues than in normal intestinal mucosa ( t=3.116, t=2.374, P<0.05, respectively). After miR-195 was transferred into SW480 cells in vitro, the luciferase activity of Dll4 decreased as compared with that in the control group (0.442±0.010, 1.010±0.002, t=4.305, P<0.01). miR-195 and dapt could block Notch1 pathway, inhibit the proliferation (3.1% vs. 17.3%, t=4.232, P<0.01) and induce apoptosis (13.7% vs. 48.3%, t=8.355, P<0.01) of SW480 cells, and they had synergistic effects ( t=7.474, P<0.01). At the same time, the expression of NICD and Hes-1 decreased with the time. Conclusion:The expression of miR-195 and Dll4 is antagonistic in CRC, which is closely related to its pathological characteristics. Dll4 is the downstream target gene regulated by miR-195. miR-195 inhibits CRC by negatively regulating Dll4/Notch signaling pathway.

BACKGROUND Colorectal liver metastases (CLM) occur in 15%-30% of patients with colorectal cancer (CRC). Advancements in next generation sequencing (NGS) can provide more precise prognoses for cancer patients and help guide clinical treatment. However, the genetic variants that predict high sensitivity to neoadjuvant chemotherapy remain unclear, especially in patients with CLM. The aim of this study was to identify the relevant genetic variants in a single CLM patient and to summarize the current evidence on mutations and single nucleotide polymorphisms (SNPs) that objectively predict sensitivity to neoadjuvant chemotherapy. CASE SUMMARY A 76-year-old male patient, who was diagnosed as stage IV colon cancer with liver metastases, was found to have APC/TP53/KRAS mutations. He showed a good therapeutic response to 12 courses of oxaliplatin regimens combined with Bevacizumab. Genetic analysis of the patient identified 5 genes with 7 detected SNPs that may be related to a better response to chemotherapy drugs. In addition, a critical literature review was performed based on a standardized appraisal form after selecting the articles. Ultimately, 21 eligible studies were appraised to assess the association between gene mutations and good prognosis. Mutations in KRAS, TP53, SMAD4, and APC were identified as being associated with a poor response to chemotherapy drugs, whereas mutations of CREBBP and POLD1 were associated with longer overall survival. CONCLUSION NGS can identify precise predictors of response to neoadjuvant chemotherapy, leading to improved outcomes for CRC patients.

Objective:To observe the expression patterns of miR-195 and DLL4 in colorectal cancer, and to explore the relationship between miR-195 and DLL4 and clinicopathological parameters and prognosis of patients with colorectal cancer.Methods:The relative expression of miR-195 in 56 colorectal cancer tissues was detected by real-time fluorescent quantitative PCR the expression of DLL4 protein and tumor microvessel density (MVD) were detected by bloting and immunohistochemistry. Colon cancer cell line SW480 was treated with miR-195. The expression of DLL4, Jagged1, (the intracellular domain of notch, NICD), CyclinD1, Hes1, Bcl-2 and NF-kB were detected by bloting.Results:The expression level of DLL4 protein in colorectal cancer tissues was significantly higher than that in normal intestinal mucosa (30/56 vs.16/56, t=5.323, P=0.018). The expression level of miR-195 was significantly lower than that in normal intestinal mucosa (36/56 vs.20/56, t=2.371, P=0.008). The expression of DLL4 was negatively correlated with the expression of miR-195 ( r=- 0.881, P=0.015) , which was closely related to the differentiation degree, lymph node metastasis and TNM stage . The prognosis of patients with high expression of DLL4 was significantly worse than that with low expression of DLL4 ( P=0.013). The prognosis of patients with low expression of miR-195 was worse than that with high expression of miR-195 ( P=0.009) . Conclusion:The antagonistic expression of miR-195 and Notch might be closely related to the occurrence and development of colorectal cancer, which can be used as a new reference index for prognosis of colorectal cancer.

Kaiso is a transcription factor in the nucleus and p120ctn-binding protein in the cytoplasm. Although it is known that p120ctn is involved in Kaiso cytoplasmic-nuclear transportation, regulatory mechanisms of Kaiso transportation remain to be explored. We firstly found that Kaiso could directly interact with 14-3-3 family proteins, depending on the phosphorylation at the 606 threonine residue (T606) within the RSSTIP motif of Kaiso. AKT1 could phosphorylate Kaiso at T606. T606A mutation abolished most Kaiso–14-3-3 interaction. Notably, we found that the phosphorylated Kaiso (pT606-Kaiso) could also bind to p120ctn in the cytoplasm and block the cytoplasmic–nuclear transportation of Kaiso. The present study indicates, for the first time, that Kaiso can be phosphorylated by AKT1 at T606 and that pT606-Kaiso can bind both 14-3-3 and p120ctn proteins in the cytoplasm. The pT606-Kaiso–p120ctn (and 14-3-3) complexes cannot shift to the nucleus and accumulate in the cytoplasm. T606 phosphorylation regulates intracellular transportation of Kaiso.

It is well known that Kaiso protein encoded by ZBTB33 gene is a transcription repressor and that Kaiso–P120ctn interaction increases the shift of Kaiso from the nucleus into the cytoplasm. However, the regulatory mechanisms of Kaiso compartmentalization are far from clear. Here, we reported that AKT1 could phosphorylate 606-threonine residue (T606) within the RSSTIP motif of Kaiso in the cytoplasm. The T606-phosphorylated Kaiso (pT606-Kaiso) could directly bind to 14-3-3 family proteins and the depletion of T606 phosphorylation by T606A mutation abolished most of the Kaiso–14-3-3 binding. In addition, the Kaiso–P120ctn interaction was essential for the pT606-Kaiso accumulation in the cytoplasm. Notably, enforced 14-3-3σ (SFN) overexpression could increase the pT606-Kaiso accumulation in the cytoplasm and de-repress the transcription of Kaiso target gene CDH1. Decreased amounts of both pT606-Kaiso and CDH1 proteins were frequently observed in human gastric cancer tissues relative to paired normal controls. The mRNA levels of 14-3-3σ and Kaiso target gene CDH1 were positively and significantly correlated with each other in bioinformatics analyses using publicly available RNA-seq datasets for human normal tissues (n=11688, r=0.60, p<0.001) in the GTEx project and for cancer cell lines (n=1156, r=0.41, p<0.001) in the CCLE project. Furthermore, Kaiso T606A mutant (unable to be phosphorylated) significantly increased the migration and invasion of cancer cells in vitro as well as boosted the growth of these cells in vivo. In conclusion, Kaiso could be phosphorylated by AKT1 at the T606 and the pT606-Kaiso accumulates in the cytoplasm through binding to 14-3-3/P120ctn that de-represses the expression of Kaiso target gene CDH1 in normal tissues. Decreased Kaiso phosphorylation may contribute to the development of gastrointestinal cancer. The status of Kaiso phosphorylation is a determinant factor for the role of Kaiso in the development of cancer.