TP53 is one of the most frequently mutated genes among all cancer types, and TP53 mutants occur more than 60% in colorectal cancer (CRC). Among all mutants, there are three hot spots, including p53-R175H, p53-R248W and p53-R273H. Emerging evidence attributes cancer carcinogenesis to cancer stem cells (CSCs). Long noncoding RNAs (lncRNAs) play crucial roles in maintaining the stemness of CSCs. However, it is unknown if mutant p53-regulated lncRNAs are implicated in the maintenance of CSC stemness. RNA-sequencing (RNA-seq) and ChIP-sequencing (ChIP-seq) were used to trace the lncRNA network regulated by p53-R273H in HCT116 endogenous p53 point mutant spheroid cells generated by the somatic cell knock-in method. RT-qPCR was used to detect lncRNA expression patterns, verifying the bioinformatics analysis. Transwell, spheroid formation, fluorescence activated cell sorter (FACS), xenograft nude mouse model, tumor frequency assessed by extreme limiting dilution analysis (ELDA), Western blot assays and chemoresistance analysis were performed to elucidate the functions and possible mechanism of lnc273–31 and lnc273–34 in cancer stem cells. p53-R273H exhibited more characteristics of CSC than p53-R175H and p53-R248W. RNA-seq profiling identified 37 up regulated and 4 down regulated differentially expressed lncRNAs regulated by p53-R273H. Combined with ChIP-seq profiling, we further verified two lncRNAs, named as lnc273–31 and lnc273–34, were essential in the maintenance of CSC stemness. Further investigation illustrated that lnc273–31 or lnc273–34 depletion dramatically diminished colorectal cancer migration, invasion, cancer stem cell self-renewal and chemoresistance in vitro. Moreover, the absence of lnc273–31 or lnc273–34 dramatically delayed cancer initiation and tumorigenic cell frequency in vivo. Also, lnc273–31 and lnc273–34 have an impact on epithelial-to mesenchymal transition (EMT). Finally, lnc273–31 and lnc273–34 were significantly highly expressed in CRC tissues with p53-R273H mutation compared to those with wildtype p53. The present study unveiled a high-confidence set of lncRNAs regulated by p53-R273H specific in colorectal CSCs. Furthermore, we demonstrated that two of them, lnc273–31 and lnc273–34, were required for colorectal CSC self-renewal, tumor propagation and chemoresistance. Also, the expression of these two lncRNAs augmented in colorectal cancer patient samples with p53-R273H mutation. These two lncRNAs may serve as promising predictors for patients with p53-R273H mutation and are vital for chemotherapy.

This study aimed to analyze clinicopathological and prognostic features of four rare pathological subtypes of primary liver malignancies to make better understanding of their clinical features. The clinicopathological data of 114 patients who were diagnosed with histologically proven four subtypes: clear cell carcinoma (CCC), giant cell carcinoma (GCC), sarcomatoid carcinoma (SC), and combined hepatocellular-cholangiocarcinoma (CHC) between October 1998 and August 2015 were reviewed. Their survival data were compared with those of 908 patients with histologically proven common hepatocellular carcinoma (HCC) (early- and advanced-stage HCC) during the same period. The outcome of the CCC group was better than that of the other three subgroups, and was similar to that of the early-stage HCC group. Also, the smallest tumor size and the highest incidence of pseudocapsule formation were observed in the CCC group. The SC group had the worst outcome among these four subgroups; the prognosis was much poorer than that of any other subgroups, even poorer than that of the advanced-stage common HCC group. No statistical difference was observed between the GCC, CHC and advanced-stage HCC groups on survival analysis. The incidences of tumor vascular emboli, TNM staging and non-radical resection were three risk factors of the prognosis. CCC is a low-degree malignancy and relatively favorably prognostic subtype of HCC. However, GCC, SC, and CHC are three rare high-degree malignancy subtypes of HCC with poor prognosis.

Background: Nivolumab and pembrolizumab disrupt the programmed cell death-1 immune checkpoint and display promising efficacy and safety results in advanced hepatocellular carcinoma (HCC). However, the benefits remain limited. The preliminary results of lenvatinib (LEN) combined with immune checkpoint inhibitors (ICIs) reveal that the combinations were well-tolerated and encouraging. This study aimed to analyze the safety and efficacy of LEN plus ICIs in a real-world cohort of patients with advanced HCC.Method: Between June 4, 2017, and June 30, 2019, 16 patients received LEN plus nivolumab, and 13 patients were treated with LEN plus pembrolizumab, with the confirmed advanced HCC retrospectively analyzed. The clinical parameters, as well as the outcomes, were assessed.Results: All the patients had Barcelona Clinical Liver Cancer Stage C. LEN with ICIs was used as systemic second-, third-, and fourth-line treatments in seven (24.1%), 14 (48.3%), and eight (27.6%) patients, respectively. At the time of data cutoff, six patients (37.5%) were still receiving LEN with nivolumab, while another six patients (46.2%) were still receiving LEN with pembrolizumab. An objective response was recorded in seven patients (25.9%), while the best overall responses were from one complete response and six partial responses. The 6- and 12-month over survival (OS) rates were 62.6% and 53.7%, respectively. Furthermore, the 6- and 12-month progression-free survival (PFS) rates were 43.5% and 31.8%, respectively. In the subgroup analyses, the 6- and 12-month OS and PFS rates for patients treated with LEN plus nivolumab were 62.5% and 52.1%, respectively, and 43.8% and 30.0%, respectively. The 6- and 12-month OS and PFS rates for patients treated with LEN plus pembrolizumab were 51.3% and 51.3%, respectively, and 49.2% and 49.2%, respectively. A total of 11 (31%) deaths were reported in this study, four of which were attributed to grade 5 adverse events presented as fatal treatment-related hepatitis.Conclusion: The combination of LEN and ICIs is a promising new strategy for the treatment of HCC patients. However, high-grade hepatic toxicity was observed and further evaluation of this combination is still required.

Background: Colorectal cancer (CRC) is one of the most common malignancies, and it’s expected that the CRC burden will substantially increase in the next two decades. New biomarkers for targeted treatment and associated molecular mechanism of tumorigenesis remain to be explored. In this study, we investigated whether PDCD6 plays an oncogenic role in colorectal cancer and its underlying mechanism. Methods: Programmed cell death protein 6 (PDCD6) expression in CRC samples were analyzed by immunohistochemistry and immunofluorescence. The prognosis between PDCD6 and clinical features were analyzed. The roles of PDCD6 in cellular proliferation and tumor growth were measured by using CCK8, colony formation, and tumor xenograft in nude mice. RNA-sequence (RNA-seq), Mass Spectrum (MS), Co-Immunoprecipitation (Co-IP) and Western blot were utilized to investigate the mechanism of tumor progression. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were performed to determine the correlation of PDCD6 and MAPK pathway. Results: Higher expression levels of PDCD6 in tumor tissues were associated with a poorer prognosis in patients with CRC. Furthermore, PDCD6 increased cell proliferation in vitro and tumor growth in vivo. Mechanistically, RNA-seq showed that PDCD6 could affect the activation of the MAPK signaling pathway. PDCD6 interacted with c-Raf, resulting in the activation of downstream c-Raf/MEK/ERK pathway and the upregulation of core cell proliferation genes such as MYC and JUN. Conclusions: These findings reveal the oncogenic effect of PDCD6 in CRC by activating c-Raf/MEK/ERK pathway and indicate that PDCD6 might be a potential prognostic indicator and therapeutic target for patients with colorectal cancer.

Background: Post-surgical recurrence of the metastatic colorectal cancer (mCRC) remains a challenge, even with adjuvant therapy. Moreover, patients show variable outcomes. Here, we set to identify gene models based on the perspectives of intrinsic cell activities and extrinsic immune microenvironment to predict the recurrence of mCRC and guide the adjuvant therapy.Methods: An RNA-based gene expression analysis of CRC samples (total = 998, including mCRCs = 344, non-mCRCs = 654) was performed. A metastasis-evaluation model (MEM) for mCRCs was developed using the Cox survival model based on the prognostic differentially expressed genes between mCRCs and non-mCRCs. This model separated the mCRC samples into high- and low-recurrence risk clusters that were tested using machine learning to predict recurrence. Further, an immune prognostic model (IPM) was built using the COX survival model with the prognostic differentially expressed immune-related genes between the two MEM risk clusters. The ability of MEM and IPM to predict prognosis was analyzed and validated. Moreover, the IPM was utilized to evaluate its relationship with the immune microenvironment and response to immuno-/chemotherapy. Finally, the dysregulation cause of IPM three genes was analyzed in bioinformatics.Results: A high post-operative recurrence risk was observed owing to the downregulation of the immune response, which was influenced by MEM genes (BAMBI, F13A1, LCN2) and their related IPM genes (SLIT2, CDKN2A, CLU). The MEM and IPM were developed and validated through mCRC samples to differentiate between low- and high-recurrence risk in a real-world cohort. The functional enrichment analysis suggested pathways related to immune response and immune system diseases as the major functional pathways related to the IPM genes. The IPM high-risk group (IPM-high) showed higher fractions of regulatory T cells (Tregs) and smaller fractions of resting memory CD4+ T cells than the IPM-low group. Moreover, the stroma and immune cells in the IPM-high samples were scant. Further, the IPM-high group showed downregulation of MHC class II molecules. Additionally, the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and GDSC analysis suggested the IPM-low as a promising responder to anti-CTLA-4 therapy and the common FDA-targeted drugs, while the IPM-high was non-responsive to these treatments. However, treatment using anti-CDKN2A agents, along with the activation of major histocompatibility complex (MHC) class-II response might sensitize this refractory mCRC subgroup. The dysfunction of MEIS1 might be the reason for the dysregulation of IPM genes.Conclusions: The IPM could identify subgroups of mCRC with a distinct risk of recurrence and stratify the patients sensitive to immuno-/chemotherapy. Further, for the first time, our study highlights the importance of MHC class-II molecules in the treatment of mCRCs using immunotherapy.

Colorectal neuroendocrine tumors with liver metastases (CRNELM) are associated with a poorer prognosis compared to their nonmetastatic counterparts. A comprehensive understanding of the tumor microenvironment (TME) heterogeneity between primary lesions (PL) and liver metastases (LM) could provide crucial insights for enhancing clinical management strategies for these patients. We utilized single-cell RNA sequencing to analyze fresh tissue samples from CRNELM patients, aiming to elucidate the variations in TME between PL and LM. Complementary multidimensional validation was achieved through spatial transcriptomics, bulk RNA sequencing, and multiplex immunohistochemistry/immunofluorescence. Our single-cell RNA sequencing analysis revealed that LM harboured a higher proportion of CD8 + T cells, CD4 + T cells, NK cells, NKT cells, and B cells exhibiting a stress-like phenotype compared to PL. RGS5 + pericytes may play a role in the stress-like phenotype observed in immune cells within LM. MCs in PL (PL_MCs) and LM (LM_MCs) exhibit distinct activation of tumor-associated signaling pathways. Notably, COLEC11 + matrix cancer-associated fibroblasts (COLEC11_mCAFs) were found to be significantly associated with LM_MCs. Cell communication analysis unveiled potential targetable receptor-ligand interactions between COLEC11_mCAFs and LM_MCs. Multidimensional validation confirmed the prominence of the characteristic stress-like phenotypes, including HSPA6_CD8_Tstr, HSPA6_NK, and COLEC11_mCAFs in LM. Moreover, a higher abundance of COLEC11_mCAFs correlated with poorer survival rates in the neuroendocrine tumor patient cohort. Overall, our study provides the first single-cell analysis of the cellular and molecular differences between PL and LM in CRNELM patients. We identified distinct cell subsets and receptor-ligand interactions that may drive TME discrepancies and support metastatic tumor growth. These insights highlight potential therapeutic targets and inform strategies for better managing CRNELM patients.