CRACD loss induces neuroendocrine cell plasticity of lung adenocarcinoma.

Tumor cell plasticity contributes to intratumoral heterogeneity and therapy resistance. Through cell plasticity, some lung adenocarcinoma (LUAD) cells transform into neuroendocrine (NE) tumor cells. However, the mechanisms of NE cell plasticity remain unclear. CRACD (capping protein inhibiting regulator of actin dynamics), a capping protein inhibitor, is frequently inactivated in cancers. CRACD knockout (KO) is sufficient to de-repress NE-related gene expression in the pulmonary epithelium and LUAD cells. In LUAD mouse models, Cracd KO increases intratumoral heterogeneity with NE gene expression. Single-cell transcriptomic analysis showed that Cracd KO-induced NE cell plasticity is associated with cell de-differentiation and stemness-related pathway activation. The single-cell transcriptomic analysis of LUAD patient tumors recapitulates that the distinct LUAD NE cell cluster expressing NE genes is co-enriched with impaired actin remodeling. This study reveals the crucial role of CRACD in restricting NE cell plasticity that induces cell de-differentiation of LUAD.

Tumor niche network-defined subtypes predict immunotherapy response of esophageal squamous cell cancer.

Despite the promising outcomes of immune checkpoint inhibitors (ICIs), resistance to ICI presents a new challenge. Therefore, selecting patients for specific ICI applications is crucial for maximizing therapeutic efficacy. Herein, we curated 69 human esophageal squamous cell cancer (ESCC) patients' tumor microenvironment (TME) single-cell transcriptomic datasets to subtype ESCC. Integrative analyses of the cellular network and transcriptional signatures of T cells and myeloid cells define distinct ESCC subtypes characterized by T cell exhaustion, and interleukin (IL) and interferon (IFN) signaling. Furthermore, this approach classifies ESCC patients into ICI responders and non-responders, as validated by whole tumor transcriptomes and liquid biopsy-based single-cell transcriptomes of anti-PD-1 ICI responders and non-responders. Our study stratifies ESCC patients based on TME transcriptional network, providing novel insights into tumor niche remodeling and potentially predicting ICI responses in ESCC patients.

Single-Cell and Spatial Transcriptome Profiling Identifies the Transcription Factor BHLHE40 as a Driver of EMT in Metastatic Colorectal Cancer.

Colorectal cancer (CRC) is one of the most common malignant tumors in humans, with liver metastasis being the primary cause of mortality. The epithelial-mesenchymal transition (EMT) process endows cancer cells with enhanced metastatic potential. To elucidate the cellular mechanisms driving EMT in CRC, we analyzed single-cell RNA-sequencing (scRNA-seq) data from 11 non-metastatic primary tumors (TnM) and 11 metastatic primary tumors (TM) from CRC patients. Compared to TnM group, the TM samples showed elevated numbers of malignant epithelial cell and cancer-associated fibroblast (CAF) subsets that displayed enrichments of EMT, angiogenesis, and TGF-ß signaling pathways. One specific TM-enriched subgroup of malignant epithelial cells underwent EMT to trans-differentiate into CXCL1+ CAFs that subsequently differentiated into SFRP2+ CAFs, which was validated by spatial transcriptomic and pseudotime trajectory analyses. Furthermore, cell-cell communication analysis identified BHLHE40 as a probable key transcription factor driving EMT that was associated with poor prognosis. Finally, in vitro and in vivo experiments functionally substantiated that BHLHE40 promoted the proliferation, invasion, migration, EMT, and liver metastasis of CRC cells. In summary, this study identified BHLHE40 as a key transcription factor regulating EMT that promotes liver metastasis in CRC.

A multiscale attribution framework for separating the effects of cascade and individual reservoirs on runoff.

Climate change and human activities have great impacts on runoff. With the gradual development of cascade hydropower in the watershed, the reservoirs have increasingly impacted runoff. However, the current study mainly focuses on quantifying the impacts of human activities and climate change on runoff, lacking the exploration of the impacts of cascade reservoirs, and the attribution results are relatively rough. Therefore, this study utilized data-driven models to establish a runoff attribution framework with the basic steps of "interval runoff prediction and scheduling rule extraction", which achieved the spatial scale separation of the impacts of cascade and individual reservoirs on the runoff, and the analysis of the impacts of each factor at multiple time scales. Taking the upper reaches of the Yangtze River mainstem as an example, we verified the applicability and accuracy of the framework, explored the impacts of climate change, human activities (without reservoir scheduling), and reservoir scheduling on runoff during the period 1980-2018. The research found: (1) Compared to the base period 1980-2005, the average multi-year runoff changes at Pingshan Station (during 2013-2018), Yichang Station (during 2006-2012) and Yichang Station (during 2013-2018) were - 2.61 %, -4.33 % and - 0.89 %, respectively, with decreasing, increasing, and flattening trends over time. (2) Reservoir scheduling is the main factor leading to runoff change, showing negative impacts during flood season and positive impacts during non-flood season. (3) Under the control domain of single and cascade reservoirs, the annual scale impacts of climate change, human activities, and reservoir scheduling on runoff accounted for approximately 1:1:8 and 2:2:6, respectively, showing a complex nonlinear relationship between the impacts of single and cascade reservoirs on runoff. This study provides ideas for quantitatively assessing the impacts of cascade reservoirs on runoff and provide a basis for comprehensively assessing the ecosystem and socio-economic impacts of reservoirs on future runoff changes.

E-cadherin loss drives diffuse-type gastric tumorigenesis via EZH2-mediated reprogramming.

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 mutations, the role of CDH1/E-cadherin inactivation in sporadic DGAC tumorigenesis remains elusive. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared with KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.

Key Genetic Determinants Driving Esophageal Squamous Cell Carcinoma Initiation and Immune Evasion.

BACKGROUND & AIMS: Despite recent progress in identifying aberrant genetic and epigenetic alterations in esophageal squamous cell carcinoma (ESCC), the mechanism of ESCC initiation remains unknown. METHODS: Using CRISPR/Cas 9-based genetic ablation, we targeted 9 genes (TP53, CDKN2A, NOTCH1, NOTCH3, KMT2D, KMT2C, FAT1, FAT4, and AJUBA) in murine esophageal organoids. Transcriptomic phenotypes of organoids and chemokine released by organoids were analyzed by single-cell RNA sequencing. Tumorigenicity and immune evasion of organoids were monitored by allograft transplantation. Human ESCC single-cell RNA sequencing data sets were analyzed to classify patients and find subsets relevant to organoid models and immune evasion. RESULTS: We established 32 genetically engineered esophageal organoids and identified key genetic determinants that drive ESCC initiation. A single-cell transcriptomic analysis uncovered that Trp53, Cdkn2a, and Notch1 (PCN) triple-knockout induces neoplastic features of ESCC by generating cell lineage heterogeneity and high cell plasticity. PCN knockout also generates an immunosuppressive niche enriched with exhausted T cells and M2 macrophages via the CCL2-CCR2 axis. Mechanistically, CDKN2A inactivation transactivates CCL2 via nuclear factor-κB. Moreover, comparative single-cell transcriptomic analyses stratified patients with ESCC and identified a specific subtype recapitulating the PCN-type ESCC signatures, including the high expression of CCL2 and CD274/PD-L1. CONCLUSIONS: Our study unveils that loss of TP53, CDKN2A, and NOTCH1 induces esophageal neoplasia and immune evasion for ESCC initiation and proposes the CCL2 blockade as a viable option for targeting PCN-type ESCC.

CRACD suppresses neuroendocrinal plasticity of lung adenocarcinoma.

Tumor cell plasticity contributes to intratumoral heterogeneity and therapy resistance. Through cell plasticity, lung adenocarcinoma (LUAD) cells transform into neuroendocrinal (NE) tumor cells. However, the mechanisms of NE cell plasticity remain unclear. CRACD, a capping protein inhibitor, is frequently inactivated in cancers. CRACD knock-out (KO) de-represses NE-related gene expression in the pulmonary epithelium and LUAD cells. In LUAD mouse models, Cracd KO increases intratumoral heterogeneity with NE gene expression. Single-cell transcriptomic analysis showed that Cracd KO-induced NE plasticity is associated with cell de-differentiation and activated stemness-related pathways. The single-cell transcriptomes of LUAD patient tumors recapitulate that the distinct LUAD NE cell cluster expressing NE genes is co-enriched with SOX2, OCT4, and NANOG pathway activation, and impaired actin remodeling. This study reveals an unexpected role of CRACD in restricting NE cell plasticity that induces cell de-differentiation, providing new insights into cell plasticity of LUAD.

CDH1 loss promotes diffuse-type gastric cancer tumorigenesis via epigenetic reprogramming and immune evasion.

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 gene mutations, causing E-Cadherin loss, its role in sporadic DGAC is unclear. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared to KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.

Tumor Niche Network-Defined Subtypes Predict Immunotherapy Response of Esophageal Squamous Cell Cancer.

Despite the promising outcomes of immune checkpoint blockade (ICB), resistance to ICB presents a new challenge. Therefore, selecting patients for specific ICB applications is crucial for maximizing therapeutic efficacy. Herein we curated 69 human esophageal squamous cell cancer (ESCC) patients' tumor microenvironment (TME) single-cell transcriptomic datasets to subtype ESCC. Integrative analyses of the cellular network transcriptional signatures of T cells, myeloid cells, and fibroblasts define distinct ESCC subtypes characterized by T cell exhaustion, Interferon (IFN) a/b signaling, TIGIT enrichment, and specific marker genes. Furthermore, this approach classifies ESCC patients into ICB responders and non-responders, as validated by liquid biopsy single-cell transcriptomics. Our study stratifies ESCC patients based on TME transcriptional network, providing novel insights into tumor niche remodeling and predicting ICB responses in ESCC patients.

CRACD loss promotes small cell lung cancer tumorigenesis via EZH2-mediated immune evasion.

The mechanisms underlying immune evasion and immunotherapy resistance in small cell lung cancer (SCLC) remain unclear. Herein, we investigate the role of CRACD tumor suppressor in SCLC. We found that CRACD is frequently inactivated in SCLC, and Cracd knockout (KO) significantly accelerates SCLC development driven by loss of Rb1, Trp53, and Rbl2. Notably, the Cracd-deficient SCLC tumors display CD8+ T cell depletion and suppression of antigen presentation pathway. Mechanistically, CRACD loss silences the MHC-I pathway through EZH2. EZH2 blockade is sufficient to restore the MHC-I pathway and inhibit CRACD loss-associated SCLC tumorigenesis. Unsupervised single-cell transcriptomic analysis identifies SCLC patient tumors with concomitant inactivation of CRACD, impairment of tumor antigen presentation, and downregulation of EZH2 target genes. Our findings define CRACD loss as a new molecular signature associated with immune evasion of SCLC cells and proposed EZH2 blockade as a viable option for CRACD-negative SCLC treatment.

Nuclear Actin Dynamics in Gene Expression, DNA Repair, and Cancer.

Actin is a highly conserved protein in mammals. The actin dynamics is regulated by actin-binding proteins and actin-related proteins. Nuclear actin and these regulatory proteins participate in multiple nuclear processes, including chromosome architecture organization, chromatin remodeling, transcription machinery regulation, and DNA repair. It is well known that the dysfunctions of these processes contribute to the development of cancer. Moreover, emerging evidence has shown that the deregulated actin dynamics is also related to cancer. This chapter discusses how the deregulation of nuclear actin dynamics contributes to tumorigenesis via such various nuclear events.

Identification and Verification of Tumor Immune Microenvironment-Related Prognostic Genes in Kidney Renal Clear Cell Carcinoma.

BACKGROUND: The tumor immune microenvironment is vital to kidney renal clear cell carcinoma (KIRC) progression, and immunotherapies have been shown to be effective in the management of KIRC. However, the prognostic genes associated with the tumor immune microenvironment in KIRC have not been fully identified. We obtained the KIRC RNA sequencing data and the clinical characteristics from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) database. We screened the gene modules associated with the tumor immune microenvironment based on the ESTIMATE algorithm and weighted gene coexpression network analysis (WGCNA). Univariate Cox analysis and the LASSO method were used to construct a prognostic model. Receiver Operating Characteristic (ROC) curve analysis was performed to evaluate the accuracy of our risk model. TIMER and Single-Sample Gene Set Enrichment Analysis (ssGSEA) were used to explore the correlation between prognostic genes and immune cell infiltration. RESULTS: Fifty-four genes in modules were significantly associated with the overall survival (OS) time of patients with KIRC. Furthermore, 12 hub genes were selected to construct the prognostic model. The prognostic model showed superior accuracy in both TCGA and ICGC cohorts using ROC curve analysis. Systematic analysis of immune cell infiltration revealed that nine genes were significantly correlated with levels of tumor-infiltrating immune cells. CONCLUSIONS: Our findings indicated that the tumor immune microenvironment was an important determinant of KIRC outcomes and revealed potential biomarkers for predicting patient OS and for targeted immunotherapies.

KIX domain determines a selective tumor-promoting role for EP300 and its vulnerability in small cell lung cancer.

EP300, a transcription coactivator important in proliferation and differentiation, is frequently mutated in diverse cancer types, including small cell lung cancer (SCLC). While these mutations are thought to result in loss of EP300 function, the impact on tumorigenesis remains largely unknown. Here, we demonstrate that EP300 mutants lacking acetyltransferase domain accelerate tumor development in mouse models of SCLC. However, unexpectedly, complete Ep300 knockout suppresses SCLC development and proliferation. Dissection of EP300 domains identified kinase inducible domain-interacting (KIX) domain, specifically its interaction with transcription factors including MYB, as the determinant of protumorigenic activity. Ala627 in EP300 KIX results in a higher protein-binding affinity than Asp647 at the equivalent position in CREBBP KIX, underlying the selectivity of KIX-binding partners for EP300. Blockade of KIX-mediated interactions inhibits SCLC development in mice and cell growth. This study unravels domain-specific roles for EP300 in SCLC and unique vulnerability of the EP300 KIX domain for therapeutic intervention.

Molecular Classification Based on Prognostic and Cell Cycle-Associated Genes in Patients With Colon Cancer.

The molecular classification of patients with colon cancer is inconclusive. The gene set enrichment analysis (GSEA) of dysregulated genes among normal and tumor tissues indicated that the cell cycle played a crucial role in colon cancer. We performed univariate Cox regression analysis to find out the prognostic-related genes, and these genes were then intersected with cell cycle-associated genes and were further recognized as prognostic and cell cycle-associated genes. Unsupervised non-negative matrix factorization (NMF) clustering was performed based on cell cycle-associated genes. Two subgroups were identified with different overall survival, clinical features, cell cycle enrichment profile, and mutation profile. Through nearest template prediction (NTP), the molecular classification could be effectively repeated in the original data set and validated in several independent data sets indicating that the classification is highly repeatable. Furthermore, we constructed two prognostic signatures in two subgroups, respectively. Our molecular classification based on cell cycle may provide novel insight into the treatment and the prognosis of colon cancer.

CircRNA circ_0124554 blocked the ubiquitination of AKT promoting the skip lymphovascular invasion on hepatic metastasis in colorectal cancer.

Colorectal cancer (CRC) is the fourth most common cancer in men and the third most common cancer in women worldwide. The incidence and mortality of CRC was increasing rapidly in China. Lymph node-negative colorectal cancer patients with synchronous liver metastasis (LNLM1) was defined as "skip" lymph vascular invasion on hepatic metastasis, who presenting poor prognosis. We aiming to investigate the potential mechanism for the "skip" lymph vascular invasion on hepatic metastasis in colorectal cancer. The microarray was applied for screening the transcription landscape of circRNA in lymph node negative CRC patients with synchronous liver metastasis (LNLM1) or without liver metastasis (LNLM0). We identified the aberrant increased circRNA circ_0124554 (also entitled as circ-LNLM) in tumor tissues of LNLM1 patients comparing with either the tumor tissues of LNLM0 or adjacent tissues of LNLM1. Circ-LNLM1 expression was highly correlated with liver metastasis and vascular invasion. Ectopic expression of cytoplasmic located circ-LNLM could promote invasion of CRC cells and induced the liver metastasis in animal models through the direct binding with AKT. The phosphorylation of AKT (T308/S473) was activated due to the blocked ubiquitination site of Lys in 0-52aa peptide of circ-LNLM. Endogenous plasma expression of circ-LNLM induced poor prognosis of LNLM1 and could distinguish LNLM1 patients from LNLM0. In conclusion, the circ-LNLM blocked the ubiquitination of AKT could promote the early metastasis especially for the lymph node-negative colorectal cancer patients with synchronous liver metastasis. The circ-LNLM might be prognosis and diagnosis biomarker for LNLM1 patients.

Infrapyloric lymph node dissection in right hemicolectomy for colon cancer: Should prophylactic resection be recommended?

BACKGROUND AND OBJECTIVES: Infrapyloric lymph node dissection in right colon cancer patients remains controversial. We aimed to investigate the pattern of infrapyloric lymph node metastasis in right colon cancer patients. METHODS: Clinical and pathological data of 140 colon cancer patients who underwent radical right hemicolectomy and infrapyloric lymph node dissection were retrospectively examined. Patient characteristics, intraoperative conditions, postoperative recovery information, postoperative pathological findings, and follow-up data were examined. RESULTS: About 19, 44, 73, and 4 patients had tumors located in the cecum, ascending colon, hepatic flexure, and right side of the transverse colon, respectively. The median number of harvested lymph nodes and that of positive lymph nodes were 24 (16-30) and 1 (0-7.75), respectively. The lymph node metastasis rate was 41.43% (58/140). The corresponding values for infrapyloric lymph nodes were 3 (1-4), 0 (0-0), and 0.71% (1/140), respectively. The median follow-up duration was 19 (0-65) months in 131 (93.6%) patients. The 5-year overall and disease-free survival rates were 86.3% and 73.5%, respectively. CONCLUSION: Given the low rate of infrapyloric lymph node metastasis in right colon cancer, lymph node dissection is recommended in patients with locally advanced colon cancer at the hepatic flexure and those with suspected infrapyloric lymph node metastasis.

Cetuximab functionalization strategy for combining active targeting and antimigration capacities of a hybrid composite nanoplatform applied to deliver 5-fluorouracil: toward colorectal cancer treatment.

Antibody-functionalized targeted nanocarriers to deliver chemotherapeutics have been widely explored. However, it remains highly desirable to understand and apply the antitumor potential of antibodies integrated in hybrid composite nanoplatforms. Herein, mesoporous silica nanoparticles, a supported lipid bilayer and cetuximab were integrated to fabricate a hybrid nanoplatform for effectively encapsulating and selectively delivering 5-fluorouracil (5-FU) against colorectal cancer (CRC) cells. The specially designed nanoplatform exhibited superior properties, such as satisfying size distribution, dispersity and stability, drug encapsulation, controlled release, and cellular uptake. Interestingly, the modification of cetuximab onto nanoplatforms without drug loading can significantly inhibit the migration and invasion of CRC cells through suppressing the epidermal growth factor receptor (EGFR)-associated signaling pathway. Furthermore, delivery of 5-FU by using this nanoplatform can remarkably induce cytotoxicity, cell cycle arrest, and cell apoptosis for CRC cells with high EGFR expression. Overall, this nanostructured platform can dramatically improve the tumor killing effects of encapsulated chemotherapeutics and present antimigration effects derived from the antibody modified on it. Moreover, in vivo biodistribution experiments demonstrated the superior tumor targeting ability of the targeted nanoparticles. Thus, this targeted nanoplatform has substantial potential in combinational therapy of antibodies and chemotherapy agents against colorectal cancer.

Long non-coding RNA Lnc-LALC facilitates colorectal cancer liver metastasis via epigenetically silencing LZTS1.

Colorectal cancer (CRC) is one of the most common cancers around the world and endangers human health seriously. Liver metastasis is an important factor affecting the long-term prognosis of CRC and the specific mechanism of CRLM (colorectal cancer with liver metastasis) is not fully understood. LZTS1 has been found dysregulated in many cancers, especially in CRC. Theories suggested that hypermethylation of the promoter regions of LZTS1 was responsible for LZTS1 abnormal expression in multiple malignant tumors. Although the role of LZTS1 in CRC cell proliferation has been reported, its role in CRLM remains unclear. Numerous studies reported Long non-coding RNA (lncRNA) could regulate the gene expression level by regulating gene methylation status in many tumors. However, whether there were lncRNAs could change the methylation status of LZTS1 or not in CRLM was unknown. In this study, we aimed to investigate whether there are lncRNAs can regulate the expression of LZTS1 through affecting DNA methylation in CRLM. We found that upregulated Lnc-LALC in CRC was negatively correlated with LZTS1 expression, and Lnc-LALC could regulate LZTS1 expression in both mRNA and protein level in our study. Functionally, Lnc-LALC enhanced the CRC cells metastasis ability in vitro and vivo through inhibiting the expression of LZTS1. Furthermore, the precise mechanisms exploration showed that lnc-LALC could recruit DNA methyltransferases (DNMTs) to the LZTS1 promoter by combining with Enhancer of zeste homolog 2(EZH2) and then altered the expression of LZTS1 via DNMTs-mediated DNA methylation. Collectively, our data demonstrated the important role of Lnc-LALC/ LZTS1 axis in CRLM development.

Targeting Wnt Signaling for Gastrointestinal Cancer Therapy: Present and Evolving Views.

Wnt signaling governs tissue development, homeostasis, and regeneration. However, aberrant activation of Wnt promotes tumorigenesis. Despite the ongoing efforts to manipulate Wnt signaling, therapeutic targeting of Wnt signaling remains challenging. In this review, we provide an overview of current clinical trials to target Wnt signaling, with a major focus on gastrointestinal cancers. In addition, we discuss the caveats and alternative strategies for therapeutically targeting Wnt signaling for cancer treatment.