Comprehensive molecular profiling of intrahepatic cholangiocarcinoma in the Chinese population and therapeutic experience

FGFR2 fusion/rearrangement analysis in intrahepatic cholangiocarcinoma using DNA/RNA-based NGS and FISH

Patients with intrahepatic cholangiocarcinoma (iCCA) harboring FGFR2 fusion/rearrangement benefit from targeted therapies, highlighting the need for reliable testing strategies to identify FGFR2 alterations. We assessed 226 iCCA cases using RNA-based NGS, DNA-based NGS, and break-apart FISH to evaluate the effectiveness of these methods in detecting FGFR2 fusion/rearrangement. The detection rates for FGFR2 fusion/rearrangement were 9.7% (22/226) for RNA-based NGS, 7.1% (16/226) for DNA-based NGS, and 10.2% (23/226) for FISH. Among the 26 FGFR2 fusion/rearrangement-positive cases identified by any method, only 15 (57.7%) were positive by all three techniques, yielding a concordance rate of 95.1% (215/226). RNA-based NGS confirmed oncogenic FGFR2 fusion in 81% (21/26) of positive cases and identified five novel oncogenic fusions. Thirty-five percent (6/17) of the partner genes were located on chromosome 10, with BICC1 being the most common fusion partner, while the rest were distributed across the other 9 chromosomes. FISH demonstrated a sensitivity of 95.2% and specificity of 98.5%, compared to oncogenic FGFR2 fusions confirmed by RNA-based NGS, while DNA-based NGS exhibited a sensitivity of 71.4% and specificity of 99.5%, identifying FGFR2 mutations in 4 cases. FGFR2-FISH positive cases displayed no significant heterogeneity in positive cell distribution. Oncogenic FGFR2 fusion/rearrangement was associated with small duct type iCCA, especially in cases with positive serum HBsAg and absent cholangiolocarcinoma components and peripheral liver steatosis. This study provides a comprehensive comparison of three assays for detecting FGFR2 fusion/rearrangement, along with clinicopathologic characterization of oncogenic FGFR2 fusion in iCCA.

Mutant KRAS and CK2 Cooperatively Stimulate SLC16A3 Activity to Drive Intrahepatic Cholangiocarcinoma Progression

Intrahepatic cholangiocarcinoma (iCCA) is a lethal malignancy affecting the liver and biliary system. Enhanced understanding of the pathogenic mechanisms underlying iCCA tumorigenesis and the discovery of appropriate therapeutic targets are imperative to improve patient outcomes. In this study, we investigated the functions and regulations of solute carrier family 16 member 3 (SLC16A3), which has been reported to be a biomarker of poor prognosis in iCCA. High SLC16A3 expression was enriched in KRAS viral oncogene homolog-mutated iCCA tumors, and mutant KRAS elevated SLC16A3 expression via the PI3K-AKT-mTORC1-HIF1α pathway. SLC16A3 not only enhanced glycolysis but also induced epigenetic reprogramming to regulate iCCA progression. Phosphorylation of SLC16A3 at S436 was vital for its oncogenic function and was linked to iCCA progression. Casein kinase 2 (CK2) directly phosphorylated SLC16A3 at S436, and CK2 inhibition with CX-4945 (silmitasertib) reduced the growth of KRAS-mutated iCCA tumor xenografts and patient-derived organoids. Together, this study provides valuable insights into the diverse functions of SLC16A3 in iCCA and comprehensively elucidates the upstream regulatory mechanisms, providing potential therapeutic strategies for patients with iCCA with KRAS mutations. Significance: Characterization of the oncogenic function and regulators of SLC16A3 in intrahepatic cholangiocarcinogenesis revealed the potential of CK2 inhibitors as a promising treatment for KRAS-mutated tumors.

Epidemiology and genomic features of biliary tract cancer and its unique features in Korea

Biliary tract cancer (BTC) is a rare but highly aggressive malignancy that includes intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, and gallbladder cancer (GBC). While BTC has a low global incidence, its regional variations are notable. Among nations, Korea has the second-highest incidence of BTC globally, with the highest mortality rate worldwide, underscoring the need for a deeper understanding of this cancer. Liver fluke infection and hepatitis B virus infection are key risk factors unique to Korea, contributing to regional differences in BTC incidence. Additionally, genomic alterations in Korean patients with BTC differ from those in other populations, including lower frequencies of IDH1 mutations and FGFR2 fusions in ICC and a higher prevalence of ERBB2 amplification in GBC. Recognizing the clinical significance of these alterations, ivosidenib and pemigatinib have been approved in Korea for BTC patients with IDH1 mutations and FGFR2 fusions, respectively. This review explores the epidemiology, risk factors, and molecular features of BTC, along with corresponding targeted therapies. Furthermore, we compare the unique characteristics of BTC in Korea with global data to inform future research and clinical practice.

Establishment of two novel organoid lines from patients with combined hepatocellular cholangiocarcinoma

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a unique subtype of primary liver cancer displaying both hepatocytic and cholangiocytic differentiation. The development of effective treatments for cHCC-CCA remains challenging because of its high heterogeneity and lack of a suitable model system. Using a three-dimensional culture system, we successfully established two novel cHCC-CCA organoid lines from patients undergoing surgical resection for primary liver cancer. cHCC-CCA organoid lines were authenticated by fingerprint analysis, and their morphology, growth kinetics, and anchorage-independent growth were also characterized. Hematoxylin and eosin staining and immunohistochemical analysis showed that the cHCC-CCA organoids preserved the growth pattern, differentiation grade, and phenotypic characteristics of their parental tumors. Whole-exome sequencing demonstrated that patient-derived cHCC-CCA organoid lines retained the genetic alterations identified in their original tumors. Subcutaneous tumors developed in immunodeficient mice after injection of cHCC-CCA organoids. Histologically, the xenografts recapitulated the features of the original cHCC-CCA tumors, harboring both HCC and intrahepatic cholangiocarcinoma components within the same tumor. The establishment of patient-derived cHCC-CCA organoid lines with high tumorigenicity provides a valuable resource for the mechanistic investigation and drug development of this disease.

Multi-Omics Classification of Intrahepatic Cholangiocarcinoma: A Systematic Review and Meta-Analysis

Intrahepatic cholangiocarcinoma (ICC) is a heterogeneous disease characterized by a dismal prognosis. Various attempts have been made to classify ICC subtypes with varying prognoses, but a consensus has yet to be reached. This systematic review aims to gather relevant data on the multi-omics-based ICC classification. The PubMed, Embase, and Cochrane databases were searched for terms related to ICC and multi-omics analysis. Studies that identified multi-omics-derived ICC subtypes and investigated clinicopathological predictors of long-term outcomes were included. Nine studies, which included 910 patients, were considered eligible. Mean 3- and 5-year overall survival were 25.7% and 19.6%, respectively, for the multi-omics subtypes related to poor prognosis, while they were 70.2% and 63.3%, respectively, for the subtypes linked to a better prognosis. Several negative prognostic factors were identified, such as genes' expression profile promoting inflammation, mutations in the KRAS gene, advanced tumor stage, and elevated levels of oncological markers. The subtype with worse clinicopathological characteristics was associated with worse survival (Ref.: good prognosis subtype; pooled hazard ratio 2.06, 95%CI 1.67-2.53). Several attempts have been made to classify molecular ICC subtypes, but they have yielded heterogeneous results and need a clear clinical definition. More efforts are required to build a comprehensive classification system that includes both molecular and clinical characteristics before implementation in clinical practice to facilitate decision-making and select patients who may benefit the most from comprehensive molecular profiling in the disease's earlier stages.

HK2 promotes migration and invasion of intrahepatic cholangiocarcinoma via enhancing cancer stem-like cells' resistance to anoikis

Cancer stem-like cells (CSLCs) and anoikis resistance play crucial roles in the metastasis of cancers. However, it remains unclear whether CSLCs are related to anoikis resistance in intrahepatic cholangiocarcinoma (ICC). Here we identified a group of stemness-related anoikis genes (SRAGs) via bioinformatic analysis of public data. Accordingly, a novel anoikis-related classification was established and it divided ICC into C1 and C2 type. Different type ICC displayed distinct prognosis, molecular as well immune characteristics. Furthermore, we found one key SRAGs via several machine learning algorithms. HK2 was up-regulated in tumor-repopulating cells (TRCs) of ICC, a kind of CSLCs with a potent resistance to anoikis. Its up-regulation may be caused by the activation of MTORC1 signaling in ICC-TRCs. And inhibition of HK2 significantly increased anoikis and decreased migration as well invasion in ICC-TRCs. Our studies provide an insight into the molecular mechanism underlying the resistance of ICC-TRCs to anoikis and enhance the evidences for targeting HK2 in ICC.

Nomogram for Predicting Survival Post-Immune Therapy in Cholangiocarcinoma Based on Inflammatory Biomarkers

BACKGROUND

Immune therapy, especially involving PD-1/PD-L1 inhibitors, has shown promise as a therapeutic option for cholangiocarcinoma. However, limited studies have evaluated survival outcomes in cholangiocarcinoma patients treated with immune therapy. This study aims to develop a predictive model to evaluate the survival benefits of immune therapy in patients with cholangiocarcinoma.

METHODS

This retrospective analysis included 120 cholangiocarcinoma patients from Shulan (Hangzhou) Hospital. Univariate and multivariate Cox regression analyses were conducted to identify factors associated with survival following immune therapy. A predictive model was constructed and validated using calibration curves (CC), decision curve analysis (DCA), concordance index (C-index), and receiver operating characteristic (ROC) curves.

RESULTS

Cox regression analysis identified several factors as potential predictors of survival post-immune therapy in cholangiocarcinoma: treatment cycle (<6 vs ≥ 6 months, 95% CI: 0.119-0.586, P = 0.001), neutrophil-to-lymphocyte ratio (NLR <3.08 vs ≥ 3.08, 95% CI: 1.864-9.624, P = 0.001), carcinoembryonic antigen (CEA <4.13 vs ≥ 4.13, 95% CI: 1.175-5.321, P = 0.017), and presence of bone metastasis (95% CI: 1.306-6.848, P = 0.010). The nomogram model achieved good predictive accuracy with a C-index of 0.811. CC indicated strong concordance between the predicted and observed outcomes. Multi-timepoint ROC curves at 1, 2, and 3 years validated the model's performance (1-year AUC: 0.906, 2-year AUC: 0.832, 3-year AUC: 0.822). The multi-timepoint DCA curves also demonstrated a higher net benefit compared to extreme curves.

CONCLUSION

The nomogram model, incorporating key risk factors for cholangiocarcinoma patients post-immune therapy, demonstrates robust predictive accuracy for survival outcomes, offering the potential for improved clinical decision-making.

Expert Consensus on Pathological Diagnosis of Intrahepatic Cholangiocarcinoma (2022 version)

Intrahepatic cholangiocarcinoma (iCCA) can originate from the large bile duct group (segment bile ducts and area bile ducts), small bile duct group (septal bile ducts and interlobular bile ducts), and terminal bile duct group (bile ductules and canals of Hering) of the intrahepatic biliary tree, which can be histopathological corresponding to large duct type iCCA, small duct type iCCA and iCCA with ductal plate malformation pattern, and cholangiolocarcinoma, respectively. The challenge in pathological diagnosis of above subtypes of iCCA falls in the distinction of cellular morphologies, tissue structures, growth patterns, invasive behaviors, immunophenotypes, molecular mutations, and surgical prognoses. For these reasons, this expert consensus provides nine recommendations as a reference for standardizing and refining the diagnosis of pathological subtypes of iCCA, mainly based on the 5th edition of the World Health Organization Classification of Tumours of the Digestive System.

Bufalin targeting CAMKK2 inhibits the occurrence and development of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) accounts for about 15% of primary liver cancer, and the incidence rate has been rising in recent years. Surgical resection is the best treatment for ICC, but the 5-year survival rate is less than 30%. ICC signature genes are crucial for the early diagnosis of ICC, so it is especially important to find its signature genes and therapeutic drug. Here, we studied that bufalin targeting CAMKK2 promotes mitochondrial dysfunction and inhibits the occurrence and metastasis of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway.

METHODS

IC50 of bufalin in ICC cells was determined by CCK8 and invasive and migratory abilities were verified by wound healing, cell cloning, transwell and Western blot. IF and IHC verified the expression of CAMKK2 between ICC patients and normal subjects. BLI and pull-down demonstrated the binding ability of bufalin and CAMKK2. Bioinformatics predicted whether CAMKK2 was related to the Wnt/β-catenin pathway. SKL2001, an activator of β-catenin, verified whether bufalin acted through this pathway. In vitro and in vivo experiments verified whether overexpression of CAMKK2 affects the proliferative and migratory effects of ICC. Transmission electron microscopy verified mitochondrial integrity. Associated Ca2+ levels verified the biological effects of ANXA2 on ICC.

RESULTS

It was found that bufalin inhibited the proliferation and migration of ICC, and CAMKK2 was highly expressed in ICC, and its high expression was positively correlated with poor prognosis.CAMKK2 is a direct target of bufalin, and is associated with the Wnt/β-catenin signaling pathway, which was dose-dependently decreased after bufalin treatment. In vitro and in vivo experiments verified that CAMKK2 overexpression promoted ICC proliferation and migration, and bufalin reversed this effect. CAMKK2 was associated with Ca2+, and changes in Ca2+ content induced changes in the protein content of ANXA2, which was dose-dependently decreasing in cytoplasmic ANXA2 and dose-dependently increasing in mitochondrial ANXA2 after bufalin treatment. In CAMKK2 overexpressing cells, ANXA2 was knocked down, and we found that reversal of CAMKK2 overexpression-induced enhancement of ICC proliferation and migration after siANXA2.

CONCLUSIONS

Our results suggest that bufalin targeting CAMKK2 promotes mitochondrial dysfunction and inhibits the proliferation and migration of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway. Thus, bufalin, as a drug, may also be used for cancer therapy in ICC in the future.

Glomangiosarcoma-like Anaplastic Transformation in Papillary Thyroid Carcinoma: A Novel Form of Heterologous Differentiation and a Systematic Review of Heterologous Element Prevalence

Anaplastic thyroid carcinoma (ATC) demonstrates a wide variety of morphologies and is characteristically associated with a differentiated thyroid carcinoma component. Heterologous differentiation is a rare, potentially challenging phenomenon in ATC, mostly observed as osteosarcomatous or chondrosarcomatous differentiation. We now describe a novel 'glomangiosarcoma-like' differentiation, review our archival experience from two institutions (UPMC, CC), and perform a systematic review for the prevalence of heterologous elements in ATC. The patient is a 57-year-old female who presented with 4.5 cm left thyroid, and 3.4 cm neck masses. Histologically, the thyroid demonstrated a differentiated high grade papillary thyroid carcinoma, tall cell and hobnail/micropapillary subtypes transitioning into an anaplastic component with spindled to ovoid cells with hemangiopericytoma-like vasculature showing CD34 positivity, variable muscle marker expression and pericellular lace-like type IV collagen deposition. The neck mass consisted solely of the latter morphology. Targeted next-generation sequencing was performed on high grade DTC and adjacent ATC from the thyroid as well as ATC from the neck metastasis. All three components shared BRAFV600E, TERT promoter, and PIK3CA mutations confirming a clonal origin. Archival (UPMC: n = 150, CC: n = 74) and literature review showed no prior examples. Systematic review and meta-analysis of prevalence showed a baseline pooled prevalence (generalized linear mixed model) of heterologous elements of any type to be 1.6% (95% confidence interval: 1.0-2.6%) for studies where this was specifically addressed. ATC with glomangiosarcoma-like heterologous differentiation is a rarity among an already rare morphologic category with unique diagnostic pitfalls.

Lacking Immunotherapy Biomarkers for Biliary Tract Cancer: A Comprehensive Systematic Literature Review and Meta-Analysis

BACKGROUND

Immunotherapy has recently been incorporated into the spectrum of biliary tract cancer (BTC) treatment. The identification of predictive response biomarkers is essential in order to identify those patients who may benefit most from this novel treatment option. Here, we propose a systematic literature review and a meta-analysis of PD-1, PD-L1, and other immune-related biomarker expression levels in patients with BTC.

METHODS

Prisma guidelines were followed for this systematic review and meta-analysis. Eligible studies were searched on PubMed. Studies published between 2017 and 2022, reporting data on PD-1/PD-L1 expression and other immune-related biomarkers in patients with BTC, were considered eligible.

RESULTS

A total of 61 eligible studies were identified. Despite the great heterogeneity between 39 studies reporting data on PD-L1 expression, we found a mean PD-L1 expression percentage (by choosing the lowest cut-off per study) of 25.6% (95% CI 21.0 to 30.3) in BTCs. The mean expression percentages of PD-L1 were 27.3%, 21.3%, and 27.4% in intrahepatic cholangiocarcinomas (iCCAs-15 studies), perihilar-distal CCAs (p/dCCAs-7 studies), and gallbladder cancer (GBC-5 studies), respectively. Furthermore, 4.6% (95% CI 2.38 to 6.97) and 2.5% (95% CI 1.75 to 3.34) of BTCs could be classified as TMB-H and MSI/MMRd tumors, respectively.

CONCLUSION

From our analysis, PD-L1 expression was found to occur approximately in 26% of BTC patients, with minimal differences based on anatomical location. TMB-H and MSI molecular phenotypes occurred less frequently. We still lack a reliable biomarker, especially in patients with mismatch-proficient tumors, and we must need to make an effort to conceive new prospective biomarker discovery studies.

Genetic alterations of KRAS and TP53 in intrahepatic cholangiocarcinoma associated with poor prognosis

The aim of this study is to investigate certain genetic features of intrahepatic cholangiocarcinoma (ICCA). A total of 12 eligible ICCA patients were enrolled, and tumor tissues from the patients were subjected to next-generation sequencing of a multi-genes panel. Tumor mutation burden (TMB), mutated genes, copy number variants (CNVs), and pathway enrichment analysis were performed. The median TMB was 2.76 Mutation/Mb (range, 0-36.62 Mutation/Mb) in ICCA patients. The top two most commonly mutated genes in ICCA were KRAS (33%) and TP53 (25%). The co-mutations of KRAS and TP53 were 16.7% (2/12) in ICCA patients. Notably, patient P6 with the highest TMB did not have KRAS and TP53 mutations. Additionally, TP53 and/or KRAS alterations were significantly associated with poor progression-free survival than those with wild type (1.4 months vs 18 months). DNA damage repair and homologs recombinant repair deficiencies were significantly associated with high TMB in ICCA cases. In conclusion, we found that certain genetic mutations of TP53 and KRAS could predict poor prognosis in ICCA patients.

Pembrolizumab in combination with gemcitabine and cisplatin compared with gemcitabine and cisplatin alone for patients with advanced biliary tract cancer (KEYNOTE-966): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Biliary tract cancers, which arise from the intrahepatic or extrahepatic bile ducts and the gallbladder, generally have a poor prognosis and are rising in incidence worldwide. The standard-of-care treatment for advanced biliary tract cancer is chemotherapy with gemcitabine and cisplatin. Because most biliary tract cancers have an immune-suppressed microenvironment, immune checkpoint inhibitor monotherapy is associated with a low objective response rate. We aimed to assess whether adding the immune checkpoint inhibitor pembrolizumab to gemcitabine and cisplatin would improve outcomes compared with gemcitabine and cisplatin alone in patients with advanced biliary tract cancer.

METHODS

KEYNOTE-966 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 175 medical centres globally. Eligible participants were aged 18 years or older; had previously untreated, unresectable, locally advanced or metastatic biliary tract cancer; had disease measurable per Response Evaluation Criteria in Solid Tumours version 1.1; and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible participants were randomly assigned (1:1) to pembrolizumab 200 mg or placebo, both administered intravenously every 3 weeks (maximum 35 cycles), in combination with gemcitabine (1000 mg/m2 intravenously on days 1 and 8 every 3 weeks; no maximum duration) and cisplatin (25 mg/m2 intravenously on days 1 and 8 every 3 weeks; maximum 8 cycles). Randomisation was done using a central interactive voice-response system and stratified by geographical region, disease stage, and site of origin in block sizes of four. The primary endpoint of overall survival was evaluated in the intention-to-treat population. The secondary endpoint of safety was evaluated in the as-treated population. This study is registered at ClinicalTrials.gov, NCT04003636.

FINDINGS

Between Oct 4, 2019, and June 8, 2021, 1564 patients were screened for eligibility, 1069 of whom were randomly assigned to pembrolizumab plus gemcitabine and cisplatin (pembrolizumab group; n=533) or placebo plus gemcitabine and cisplatin (placebo group; n=536). Median study follow-up at final analysis was 25·6 months (IQR 21·7-30·4). Median overall survival was 12·7 months (95% CI 11·5-13·6) in the pembrolizumab group versus 10·9 months (9·9-11·6) in the placebo group (hazard ratio 0·83 [95% CI 0·72-0·95]; one-sided p=0·0034 [significance threshold, p=0·0200]). In the as-treated population, the maximum adverse event grade was 3 to 4 in 420 (79%) of 529 participants in the pembrolizumab group and 400 (75%) of 534 in the placebo group; 369 (70%) participants in the pembrolizumab group and 367 (69%) in the placebo group had treatment-related adverse events with a maximum grade of 3 to 4. 31 (6%) participants in the pembrolizumab group and 49 (9%) in the placebo group died due to adverse events, including eight (2%) in the pembrolizumab group and three (1%) in the placebo group who died due to treatment-related adverse events.

INTERPRETATION

Based on a statistically significant, clinically meaningful improvement in overall survival compared with gemcitabine and cisplatin without any new safety signals, pembrolizumab plus gemcitabine and cisplatin could be a new treatment option for patients with previously untreated metastatic or unresectable biliary tract cancer.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.

Non-surgical treatment of hilar cholangiocarcinoma

Cancer of the biliary confluence also known as hilar cholangiocarcinoma (HC) or Klatskin tumor, is a rare type of neoplastic disease constituting approximately 40%-60% of intrahepatic malignancies, and 2% of all cancers. The prognosis is extremely poor and the majority of Klatskin tumors are deemed unresectable upon diagnosis. Most patients with unresectable bile duct cancer die within the first year after diagnosis, due to hepatic failure, and/or infectious complications secondary to biliary obstruction. Curative treatments include surgical resection and liver transplantation in highly selected patients. Nevertheless, very few patients are eligible for surgery or transplant at the time of diagnosis. For patients with unresectable HC, radiotherapy, chemotherapy, photodynamic therapy, and liver-directed minimally invasive procedures such as percutaneous image-guided ablation and intra-arterial chemoembolization are recommended treatment options. This review focuses on currently available treatment options for unresectable HC and discusses future perspectives that could optimize outcomes.

Traditional Chinese Medicine (TCM) in the treatment of COVID-19 and other viral infections: Efficacies and mechanisms

COVID-19 has remained an uncontained, worldwide pandemic. While battling for the disease in China, six Traditional Chinese Medicine (TCM) recipes have been shown to be remarkably effective for treating patients with COVID-19. The present review discusses principles of TCM in curing infectious disease, and clinical evidence and mechanisms of the 6 most effective TCM recipes used in treating COVID-19 in 92% of all of the confirmed cases in China. Applications of TCM and specific recipes in the treatment of other viral infections, such as those caused by SARS-CoV, MERS-CoV, hepatitis B virus, hepatitis C virus, influenza A virus (including H1N1 and H7N9), influenza B, dengue virus as well as Ebola virus, are also discussed. Among the 6 TCM recipes, Jinhua Qinggan (JHQG) granules and Lianhua Qingwen (LHQW) capsules are recommended during medical observation; Lung Cleansing and Detoxifying Decoction (LCDD) is recommended for the treatment of both severe and non-severe patients; Xuanfeibaidu (XFBD) granules are recommended for treating moderate cases; while Huashibaidu (HSBD) and Xuebijing (XBJ) have been used in managing severe cases effectively. The common components and the active ingredients of the six TCM recipes have been summarized to reveal most promising drug candidates. The potential molecular mechanisms of the active ingredients in the six TCM recipes that target ACE2, 3CLpro and IL-6, revealed by molecular biological studies and/or network pharmacology prediction/molecular docking analysis/visualization analysis, are fully discussed. Therefore, further investigation of these TCM recipes may be of high translational value in enabling novel targeted therapies for COVID-19, potentially via purification and characterization of the active ingredients in the effective TCM recipes.

ARID1A Variations in Cholangiocarcinoma: Clinical Significances and Molecular Mechanisms

Cholangiocarcinoma (CCA), a high mortality malignant carcinoma characterized by advanced disease and frequent recurrence, constitutes a major challenge for treatment and prognosis. AT-rich interaction domain 1A (ARID1A) variation is a distinct genetic entity in CCA, getting mounting concerns recently. Here, we comprehensively reviewed the clinical significance and molecular mechanisms of ARID1A alterations in CCA. Based on the independent data derived from 29 relevant studies, the variation rate of ARID1A in intrahepatic and extrahepatic CCA is reported at 6.9-68.2% and 5-55%, respectively. Most of the included studies (28/29, 96.6%) suggest that ARID1A serves as a tumor suppressor in CCA. ARID1A variation may be an important prognostic indicator to predict disease mortality, metastasis, and recurrence in patients with CCA. Multifactorial molecular mechanisms are involved in the relationship between ARID1A variations and the pathogenesis and pathophysiology of CCA, including disruption of the cell cycle, chromatin remodeling, oxidative stress damage, DNA hypermethylation, and the interaction of multiple genes being affected. This review describes that ARID1A variation might be a potential diagnostic and prognostic biomarker for CCA. Future diagnoses and treatments targeting ARID1A hint towards a precision medicine strategy in the management of CCA.

Development of Possible Next Line of Systemic Therapies for Gemcitabine-Resistant Biliary Tract Cancers: A Perspective from Clinical Trials

Biliary tract cancer (BTC) compromises a heterogenous group of tumors with poor prognoses. Curative surgery remains the first choice for localized disease; however, most BTC patients have had unresectable or metastatic disease. The gold standard therapy for these patients is chemotherapy with gemcitabine and cisplatin. There are no consensus guidelines for standard treatment in a second-line setting, although the data of the ABC-06 trial showed a slight survival benefit from oxaliplatin and 5-fluorouracil combination chemotherapy. Recent progress in comprehensive genomic profiling for advanced BTC (ABTC) has helped to clarify tumorigenesis and facilitate the coming era of precision medicine. Generally, targeted agents fail to show significant clinical benefits in unselected populations. Only fibroblast growth factor receptor 2 (FGFR2) fusion and isocitrate dehydrogenase (IDH)- and BRAF mutation-enriched populations have survival benefits from the corresponding inhibitors. Several interesting targeted agents for monotherapies or combination therapies with other compounds are currently ongoing or recruiting. Here, we review the published data from clinical trials of second-line therapies after the failure of gemcitabine-based chemotherapy in ABTC. The results were stratified by different genetic alternations, as well as by chemotherapy, targeted therapy and immunotherapy.