Dichotomous roles of ADAR1 in liver hepatocellular carcinoma and kidney renal cell carcinoma: Unraveling the complex tumor microenvironment and prognostic significance.

BACKGROUND: Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that significantly impacts cancer progression and various biological processes. The expression of ADAR1 mRNA has been examined in multiple cancer types using The Cancer Genome Atlas (TCGA) dataset, revealing distinct patterns in kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), and liver hepatocellular carcinoma (LIHC) compared to normal controls. However, the reasons for these differential expressions remain unclear. METHODS: In this study, we performed RT-PCR and western blotting (WB) to validate ADAR1 expression patterns in clinical tissue samples. Survival analysis and immune microenvironment analysis (including immune score and stromal score) were conducted using TCGA data to determine the specific cell types associated with ADAR1, as well as the key genes in those cell types. The relationship between ADAR1 and specific cell types' key genes was verified by immunohistochemistry (IHC), using clinical liver and kidney cancer samples. RESULTS: Our validation analysis revealed that ADAR1 expression was downregulated in KICH, KIRC, and KIRP, while upregulated in LIHC compared to normal tissues. Notably, a significant correlation was found between ADAR1 mRNA expression and patient prognosis, particularly in KIRC, KIRP, and LIHC. Interestingly, we observed a positive correlation between ADAR1 expression and stromal scores in KIRC, whereas a negative correlation was observed in LIHC. Cell type analysis highlighted distinct relationships between ADAR1 expression and the two stromal cell types, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs), and further determined the signature gene claudin-5 (CLDN5), in KIRC and LIHC. Moreover, ADAR1 was inversely related with CLDN5 in KIRC (n = 26) and LIHC (n = 30) samples, verified via IHC. CONCLUSIONS: ADAR1 plays contrasting roles in LIHC and KIRC, associated with the enrichment of BECs and LECs within tumors. This study sheds light on the significant roles of stromal cells within the complex tumor microenvironment (TME) and provides new insights for future research in tumor immunotherapy and precision medicine.

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma: A comprehensive review.

The tumor microenvironment is a complex network of cells, extracellular matrix, and signaling molecules that plays a critical role in tumor progression and metastasis. Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits. However, recent studies have shown that lymphatic endothelial cells (LECs) and blood endothelial cells (BECs) also play multifaceted roles in the tumor microenvironment beyond their structural functions, particularly in hepatocellular carcinoma (HCC). This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC, including their involvement in angiogenesis, immune modulation, lymphangiogenesis, and metastasis. By providing a detailed account of the complex interplay between LECs, BECs, and tumor cells, this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.

Merged hepatopulmonary features in hepatoid adenocarcinoma of the lung: a systematic review.

This study aimed to provide diagnostic clues for patients with elevated serum alpha-fetoprotein (AFP) in the absence of liver tumors and rectify some previously confused concepts about hepatoid carcinoma of the lung through a systematic review on hepatoid adenocarcinoma of the lung (HAL). A thorough search for original articles on HAL published prior to November 2020 was performed using the PubMed, EBSCOhost, Embase, WanFang Data, and China National Knowledge Infrastructure (CNKI) databases. Ninety-four patients from 88 studies met the eligibility criteria. HAL was rare and mainly occurred among male Asian smokers in their 60 s, presenting with cough, hemoptysis, chest pain, dyspnea and/or weight loss, as well as elevated serum AFP with a mass usually in the right upper lung lobe but no liver masses. Hepatoid differentiation regions, acinar or papillary structures in tumor tissues, and positive immunohistochemical expression of AFP, HepPar-1, and CK8/18 were crucial indicators for the diagnosis of HAL. Surgery-based strategies were recommended for stage I-III patients, while stage IV patients were mainly treated with chemotherapy-based strategy. The 1-, 3-, and 5-year overall survival rates were 40%, 35%, and 19%, respectively. The 1-year relapse-free survival rate was 58%. The postoperative monitoring of AFP contributed to the early detection of tumor recurrence, with a positive rate of 71.43%. In conclusion, patients with elevated serum AFP levels without any detectable hepatic lesions should be evaluated for the possibility of HAL.

Acute rejection after liver transplantation is less common, but predicts better prognosis in HBV-related hepatocellular carcinoma patients.

BACKGROUND: With a novel finding of significantly lower incidence of acute rejection (AR) in patients with hepatocellular carcinoma (HCC) after liver transplantation, compared with those with benign end-stage liver disease (BESLD), in a large national cohort, we analyzed the correlations among the perioperative immuno-inflammation status, postoperative AR, and prognosis in HCC and BESLD patients with same etiology of hepatitis B virus (HBV), who underwent liver transplantation. METHODS: Patients who underwent liver transplantation due to HBV-related HCC or BESLD and experienced AR between September 2008 and April 2017 were analyzed retrospectively and followed up until April 2018. HCC patients with AR were matched with those without AR according to tumor stage and immunosuppressant concentration, at a 1:3 ratio. Preoperative immuno-inflammation status and prognosis of patients in both groups were compared. RESULTS: The overall incidences of AR in patients with HCC and BESLD were 8.60% and 10.61%, respectively. The postoperative 28-day incidence of AR was significantly lower in HCC compared with BESLD patients (3.23% vs 7.08%, p = 0.031). Compared with BESLD patients, the rejection activity index and perioperative CD4/CD8 ratio were significantly lower (p = 0.047 and p < 0.001, respectively), while platelet/lymphocyte ratio was significantly higher in HCC patients (p = 0.041). Later tumor stage in HCC patients was associated with higher systemic immuno-inflammation index, neutrophil/lymphocyte ratio, monocyte/lymphocyte ratio, platelet/lymphocyte ratio, aspartate aminotransferase/lymphocyte ratio, C-reactive protein/albumin ratio and fibrinogen level, and lower CD4/CD8 ratio before transplantation. In HCC patients with AR, the percentage of regulatory T cells (CD4+/CD25+) and the level of IL-10 significantly decreased (p = 0.0023, < 0.0001, respectively), while Th1/Th2 ratio, levels of IFN-γ and IL-2 markedly increased before transplantation (p = 0.0018, 0.0059, 0.0416, respectively). Preoperative monocyte/lymphocyte ratio was an independent risk factor for overall and recurrence-free survival after liver transplantation in HCC patients (p = 0.025, < 0.001, respectively). The 1-, 3-, and 5-year survival rates were 76%, 71% and 53% in the AR group, and 67%, 37% and 25% in the non-AR group (p = 0.042). CONCLUSION: Preoperative tumor-related immunosuppression may persist after liver transplantation in HCC patients, and reduce the incidence of AR. AR after liver transplantation may indicate a better prognosis in HCC patients.

Two case reports and literature review for hepatic epithelioid angiomyolipoma: Pitfall of misdiagnosis.

BACKGROUND: Hepatic epithelioid angiomyolipoma (HEAML) is a rare liver disease and is easily misdiagnosed. Enhanced recognition of HEAML is beneficial to the differential diagnosis of rare liver diseases. CASE SUMMARY: We presented two cases of HEAML in Changzheng Hospital, Naval Medical University, and then collected and analyzed all reports about HEAML recorded in PubMed, MEDLINE, China Science Periodical Database, and VIP database from January 2000 to March 2018. A total of 409 cases of HEAML in 97 reports were collected, with a ratio of men to women of 1:4.84 and an age range from 12 years to 80 years (median 44 years). Among the patients with clinical symptoms mentioned, 61.93% (205/331) were asymptomatic, 34.74% (115/331) showed upper or right upper quadrant abdomen discomfort, while a few of them showed abdominal mass, gastrointestinal symptoms, low fever, or weight loss. The misdiagnosis rate of HEAML was as high as 40.34% (165/409) due to its nonspecific imaging findings. Most of the tumors were solitary and round in morphology, with clear boundaries. Ultrasound scan indicated low echo with internal nonuniformity and rich blood supply in most cases. Computer tomography/magnetic resonance imaging enhanced scan showed varied characteristics. The ratio of fast wash-in and fast wash-out, fast wash-in and slow wash-out, and delayed enhancement was roughly 4:5:1. A definite diagnosis of HEAML depended on the pathological findings of the epithelioid cells in lesions and the expression of human melanoma black 45, smooth muscle actin, melanoma antigen, and actin by immunohistochemical staining. HEAML had a relatively low malignant rate of 3.91%. However, surgical resection was the main treatment for HEAML, due to the difficulty diagnosing before operation. CONCLUSION: HEAML is a rare and easily misdiagnosed disease, and it should be diagnosed carefully, taking into account clinical course, imaging, pathological ,and immunohistochemical findings.