A Lactate-Depleting metal organic framework-based nanocatalyst reinforces intratumoral T cell response to boost anti-PD1 immunotherapy.

Infiltration and activation of intratumoral T lymphocytes are critical for immune checkpoint blockade (ICB) therapy. Unfortunately, the low tumor immunogenicity and immunosuppressive tumor microenvironment (TME) induced by tumor metabolic reprogramming cooperatively hinder the ICB efficacy. Herein, we engineered a lactate-depleting MOF-based catalytic nanoplatform (LOX@ZIF-8@MPN), encapsulating lactate oxidase (LOX) within zeolitic imidazolate framework-8 (ZIF-8) coupled with a coating of metal polyphenol network (MPN) to reinforce T cell response based on a "two birds with one stone" strategy. LOX could catalyze the degradation of the immunosuppressive lactate to promote vascular normalization, facilitating T cell infiltration. On the other hand, hydrogen peroxide (H2O2) produced during lactate depletion can be transformed into anti-tumor hydroxyl radical (•OH) by the autocatalytic MPN-based Fenton nanosystem to trigger immunogenic cell death (ICD), which largely improved the tumor immunogenicity. The combination of ICD and vascular normalization presents a better synergistic immunopotentiation with anti-PD1, inducing robust anti-tumor immunity in primary tumors and recurrent malignancies. Collectively, our results demonstrate that the concurrent depletion of lactate to reverse the immunosuppressive TME and utilization of the by-product from lactate degradation via cascade catalysis promotes T cell response and thus improves the effectiveness of ICB therapy.

An Immunocompetent Hafnium Oxide-Based STING Nanoagonist for Cancer Radio-immunotherapy.

cGAS-STING signaling plays a critical role in radiotherapy (RT)-mediated immunomodulation. However, RT alone is insufficient to sustain STING activation in tumors under a safe X-ray dose. Here, we propose a radiosensitization cooperated with cGAS stimulation strategy by engineering a core-shell structured nanosized radiosensitizer-based cGAS-STING agonist, which is constituted with the hafnium oxide (HfO2) core and the manganese oxide (MnO2) shell. HfO2-mediated radiosensitization enhances immunogenic cell death to afford tumor associated antigens and adequate cytosolic dsDNA, while the GSH-degradable MnO2 sustainably releases Mn2+ in tumors to improve the recognition sensitization of cGAS. The synchronization of sustained Mn2+ supply with cumulative cytosolic dsDNA damage synergistically augments the cGAS-STING activation in irradiated tumors, thereby enhancing RT-triggered local and system effects when combined with an immune checkpoint inhibitor. Therefore, the synchronous radiosensitization with sustained STING activation is demonstrated as a potent immunostimulation strategy to optimize cancer radio-immuotherapy.

Primary pulmonary hyalinizing clear cell carcinoma with fusions of both EWSR1::CREM and IRF2::NTRK3: report of a case with an aggressive behavior.

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a rare salivary gland-type tumor newly recognized in recent years, with approximately 21 cases reported to date in the English literature, which constitutes a challenge in pathology diagnosis, particularly in small biopsy specimens. Here, we present a case of pulmonary HCCC diagnosed by computed tomography-guided percutaneous lung biopsy in a 70-year-old man's right lower lung. Although the morphology and immunophenotype of the tumor suggested the diagnosis of mucoepidermoid carcinoma, fluorescence in situ hybridization failed to reveal the rearrangement of MAML2 gene, which is characteristic of mucoepidermoid carcinoma. Instead, further molecular genetic testing showed that the tumor harbored a rare EWSR1::CREM fusion combined with a previously unreported IRF2::NTRK3 fusion. Pulmonary HCCC is commonly regarded as a low-grade malignant tumor with an indolent course, but this case has a different biological behavior, presenting extensive dissemination and metastases at the time of diagnosis, which expands our understanding of the prognosis of this tumor. The patient has had five cycles of combination chemotherapy and has been alive with the tumor for eight months.

A MOF-Based Potent Ferroptosis Inducer for Enhanced Radiotherapy of Triple Negative Breast Cancer.

Radiotherapy (RT) is one of the important clinical treatments for local control of triple-negative breast cancer (TNBC), but radioresistance still exists. Ferroptosis has been recognized as a natural barrier for cancer progression and represents a significant role of RT-mediated anticancer effects, while the simultaneous activation of ferroptosis defensive system during RT limits the synergistic effect between RT and ferroptosis. Herein, we engineered a tumor microenvironment (TME) degradable nanohybrid with a dual radiosensitization manner to combine ferroptosis induction and high-Z effect based on metal-organic frameworks for ferroptosis-augmented RT of TNBC. The encapsulated l-buthionine-sulfoximine (BSO) could inhibit glutathione (GSH) biosynthesis for glutathione peroxidase 4 (GPX4) inactivation to break down the ferroptosis defensive system, and the delivered ferrous ions could act as a powerful ferroptosis executor via triggering the Fenton reaction; the combination of them induces potent ferroptosis, which could synergize with the surface decorated Gold (Au) NPs-mediated radiosensitization to improve RT efficacy. In vivo antitumor results revealed that the nanohybrid could significantly improve the therapeutic efficacy and antimetastasis efficiency based on the combinational mechanism between ferroptosis and RT. This work thus demonstrated that combining RT with efficient ferroptosis induction through nanotechnology was a feasible and promising strategy for TNBC treatment.

Neutralizing IL-8 potentiates immune checkpoint blockade efficacy for glioma.

Malignant gliomas are largely refractory to immune checkpoint blockade (ICB) therapy. To explore the underlying immune regulators, we examine the microenvironment in glioma and find that tumor-infiltrating T cells are mainly confined to the perivascular cuffs and express high levels of CCR5, CXCR3, and programmed cell death protein 1 (PD-1). Combined analysis of T cell clustering with T cell receptor (TCR) clone expansion shows that potential tumor-killing T cells are mainly categorized into pre-exhausted/exhausted and effector CD8+ T subsets, as well as cytotoxic CD4+ T subsets. Notably, a distinct subpopulation of CD4+ T cells exhibits innate-like features with preferential interleukin-8 (IL-8) expression. With IL-8-humanized mouse strain, we demonstrate that IL-8-producing CD4+ T, myeloid, and tumor cells orchestrate myeloid-derived suppressor cell infiltration and angiogenesis, which results in enhanced tumor growth but reduced ICB efficacy. Antibody-mediated IL-8 blockade or the inhibition of its receptor, CXCR1/2, unleashes anti-PD-1-mediated antitumor immunity. Our findings thus highlight IL-8 as a combinational immunotherapy target for glioma.

Comparison of antegrade robotic assisted VS laparoscopic inguinal lymphadenectomy for penile cancer.

BACKGROUND: Minimally invasive modifications of inguinal lymphadenectomy (IL), including laparoscopic IL (LIL) and robotic-assisted IL (RAIL), have been utilized for penile cancer. Comparative study is necessary to guide the decision about which minimally invasive technique to select for IL. Therefore we compared RAIL with LIL performed via an antegrade approach in terms of perioperative outcomes. METHODS: We conducted a retrospective study of 43 patients who underwent RAIL (n = 20) or LIL (n = 23) for penile cancer from 2016 to 2020. The key surgical procedures and techniques are described. Complications were graded by the Clavien-Dindo classification, and operative time, estimated blood loss (EBL), lymph nodal yield, nodal positivity, postoperative drain duration, and disease recurrence during follow-up were assessed. Categorical variables were compared using chi-squared whereas continuous variables were compared by t-tests. RESULTS: The operative time for RAIL was significantly shorter than that of LIL (median 83 vs 95 min). Significantly less blood loss was reported with RAIL than with LIL (median 10 vs 35 ml). Lymph node yield, pathological positive nodes, the hospital stay, postoperative drain duration, postoperative complications and recurrence were similar for RAIL and LIL. CONCLUSIONS: For patients with penile cancer, perioperative outcomes of RAIL and LIL were similar, but there was less blood loss, a shorter operative time for robotic cases.

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.

Perivascular Epithelioid Cell Tumor of Urinary Bladder.

OBJECTIVES: To review the clinicopathologic features of perivascular epithelioid cell tumor (PEComa) of the urinary bladder. METHODS: Seven cases of bladder PEComa were studied by light microscopy, immunohistochemistry, and fluorescence in situ hybridization (FISH). RESULTS: In our 7 cases, 5 patients were female and 2 were male, with ages between 26 and 78 years. Patients presented with hematuria and recurrent abdominal discomfort as the main clinical symptoms. Microscopically, the epithelioid and spindle-shaped tumor cells with clear to granular eosinophilic cytoplasm were arranged in fascicular, acinar, or nested patterns. The tumor cells were positive for HMB45, melan-A, and SMA, but no TFE3 gene rearrangement was detected in any of the 7 samples by FISH. The analysis of all 35 cases from the literature and ours showed a patient age range from 16 to 78 years (mean age, 39 years), a male-to-female ratio of 1:1.3, maximal tumor diameters from 0.6 to 18.8 cm (mean, 4.5 cm). With a mean follow-up of 27 months, the recurrence, metastasis, and mortality rates were 10.7%, 10.7%, and 7.1%, respectively. CONCLUSIONS: Bladder PEComa is extremely rare, remains a diagnostic challenge, and needs more attention. Strengthening the understanding of this tumor will improve diagnostic accuracy.

A standardized pathological proposal for evaluating microvascular invasion of hepatocellular carcinoma: a multicenter study by LCPGC.

BACKGROUND AND AIMS: Microvascular invasion (MVI) is a key pathological factor that severely affects the postoperative prognosis of patients with hepatocellular carcinoma (HCC). However, no MVI classification schemes based on standardized gross sampling protocols of HCC are available at present. METHODS: 119 HCC specimens were sampled at multiple sites (3-, 7-, and 13 points) for the optimum MVI detection rate. 16,144 resected HCCs were graded as M0, M1 or M2 by adopting three-tiered MVI grading (MVI-TTG) scheme based on the seven-point sampling protocol (SPSP). Survival analyses were performed on 2573 patients to explore the advantages of MVI-TTG. RESULTS: The MVI detection rate determined by SPSP was significantly higher than that determined by the 3-point sampling method (34.5% vs. 47.1%, p = 0.048), but was similar to that determined by the 13-point sampling method (47.1% vs. 51.3%, p = 0.517). Among 16,144 resected HCCs, the proportions of M0, M1 and M2 specimens according to SPSP were 53.4%, 26.2% and 20.4%, respectively. Postoperative survival analysis in 2573 HCC patients showed that the 3-year recurrence rates in M0, M1 and M2 MVI groups were 62.5%, 71.6% and 86.1%, respectively (p < 0.001), and the corresponding 3-year overall survival (OS) rates were 94.1%, 87.5% and 67.0%, respectively (p < 0.001). M1 grade was associated with early recurrence, while M2 grade was associated with both early and late recurrence. MVI-TTG had a larger area under the curve and net benefit rate than the two-tiered MVI grading scheme for predicting time to recurrence and OS. CONCLUSIONS: SPSP is a practical method to balance the efficacy of sampling numbers and MVI detection rates. MVI-TTG based on SPSP is a better prognostic predictor than the two-tiered MVI scheme. The combined use of SPSP and MVI-TTG is recommended for the routine pathological diagnosis of HCC.

Ubiquitination-mediated degradation of SIRT1 by SMURF2 suppresses CRC cell proliferation and tumorigenesis.

The NAD-dependent deacetylase sirtuin 1 (SIRT1), a member of the mammalian sirtuin family, plays a pivotal role in deacetylating histone and nonhistone proteins. Recently, it has been reported that SIRT1 is upregulated in various kinds of tumors and is associated with cell growth and metastasis. However, the factors and molecular mechanism regulating its cellular levels remain to be clarified. Here, we reported that the E3 ubiquitin ligase SMURF2 interacts with SIRT1 and mediates its ubiquitination and degradation. Depletion of SMURF2 leads to SIRT1 upregulation and induces the tumor formation and growth of colorectal cancer in vitro and in vivo. Furthermore, we show a negative correlation between SIRT1 and SMURF2 expression in human colorectal cancer. Thus, we propose a novel mechanism of colorectal tumorigenesis via SIRT1 regulation by SMURF2, which could potentially give rise to a new strategy for the treatment of colorectal cancer.

E3 Ubiquitin Ligase HRD1 Promotes Lung Tumorigenesis by Promoting Sirtuin 2 Ubiquitination and Degradation.

The NAD-dependent histone deacetylase sirtuin 2 (SIRT2) plays critical roles in mitosis and cell cycle progression and recently was shown to suppress tumor growth and to be downregulated in several types of cancers. However, the underlying mechanism of SIRT2 downregulation remains unknown. In this study, using bioinformatics, gene expression profiling, protein overexpression approaches, and cell migration assays, we showed that E3 ubiquitin ligase 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase degradation 1 (HRD1) interacts with SIRT2 and promotes its ubiquitination and degradation. Furthermore, we found that HRD1 deficiency induces SIRT2 upregulation and inhibits the growth and tumor formation of lung cancer cells both in vitro and in vivo Of note, we observed that SIRT2 expression is downregulated in human lung cancer and also negatively correlates with HRD1 expression in these cancers. Additionally, we found that patients with lung adenocarcinoma having lower HRD1 or higher SIRT2 expression levels tend to survive longer. On the basis of these results, we propose a mechanism of lung tumorigenesis that involves HRD1-mediated downregulation of SIRT2 and suggest that interventions targeting HRD1 activity could be a potential therapeutic strategy to treat patients with lung cancer.

Nodal follicular dendritic cell sarcoma with four atypical histomorphologic features: an unusual case report.

BACKGROUND: Follicular dendritic cell sarcoma (FDCS) is a rare malignancy. In addition to the classical histopathologic features, it has also some special morphological variants that can present a challenge in the diagnosis of this disease. CASE PRESENTATION: A 45-year-old male who presented with a left supraclavicular mass was given a final diagnosis of FDCS after lymph node biopsy. The specimen obtained during radical resection revealed five different morphologies, including the classical histological appearance and atypical areas resembling desmoplastic infiltrative carcinoma, anaplastic large cell lymphoma (ALCL), hemangiopericytoma and classical Hodgkin's lymphoma (CHL). Immunohistochemistry was notable for positive CD21 and CD23 expression across all morphologies. Given the atypical appearance and location, the specimen was initially misdiagnosed as a metastatic carcinoma based on histology alone at an outside institution. The patient eventually underwent surgical resection followed by adjuvant chemotherapy and radiation. Despite treatment, the disease progressed, and the patient passed away 36 months after surgery. CONCLUSIONS: This unusual case of FDCS contains four types of atypical histomorphologies within a single tumor specimen, including those resembling ALCL and hemangiopericytoma which are described here for the first time. Our report further expands the histopathologic spectrum of FDCS and may help assist in the diagnosis of other such challenging cases.

Sensitive and selective detections of codon 12 and 13 KRAS mutations in a single tube using modified wild-type blocker.

It was hypothesized that in the WTB-PCR system, the greater number of cycles, associated with the thermodynamic driving force of DNA polymerase resulted in artificial introduction of mutant nucleotides in amplicons. In the current study, universal WTB-PCR was developed to overcome these limitations, in which two strategies were used: phosphorothioate modifications were made at the 5'-termini bases of the WTB oligonucleotides, and amplification of referenced internal positive controller (RIPC) fragments was performed. The results showed that universal WTB-PCR could detect single-copy KRAS mutant alleles with higher selectivity (i.e., 0.01%), and with greater ability to eliminate non-specific amplification of KRAS wild-type alleles in amounts up to 200 ng. Moreover, the introduction of referenced internal positive controller (RIPC) fragments prevented false-negative results caused by inadequate amounts of input sample DNA, and allowed for quantitative analysis of the mutation levels in each FFPE sample. In clinical application in 50 samples of FFPE tissue sections from mCRC patients, 70% (35/50) showed various mutations at codons 12 and 13 of KRAS genes; 30% (15/50) could be detected by traditional PCR without WTB oligonucleotides. In conclusion, universal WTB-PCR is a rapid, simple and low-cost method for detection of low-abundance KRAS mutations in mCRC patients.

Reversible regulation of SATB1 ubiquitination by USP47 and SMURF2 mediates colon cancer cell proliferation and tumor progression.

Upregulation of special AT-rich sequence-binding protein-1 (SATB1) has been suggested to promote tumor growth and metastasis. However, the factors governing its cellular levels remain unclear. Here, we report that ubiquitin-specific peptidase 47 (USP47), a member of the deubiquitinating enzymes family, interacts with SATB1 and mediates its deubiquitination and stability. USP47 deficiency impairs transcriptional activity of SATB1 target genes and inhibits colon cancer cell proliferation, migration, and tumorigenesis in a mouse model of colon cancer. Furthermore, we identified SMURF2 as an E3 ubiquitin ligase that promotes SATB1 degradation by upregulating its ubiquitination, and its deficiency promotes colon cancer cell proliferation and SATB1 target gene transcription. SMURF2 is negatively regulated by USP47, and USP47 depletion sensitizes colon cancer cells to 5-FU treatment-induced apoptosis. Taken together, our findings provide a ubiquitination-related mechanistic link to USP47, SMURF2, and SATB1 and suggest that USP47 might be targeted for colon cancer treatment when SATB1 is overexpressed.

Mediastinal follicular dendritic cell sarcoma: a rare, potentially under-recognized, and often misdiagnosed disease.

BACKGROUND: Mediastinal follicular dendritic cell sarcoma (FDCS) is extremely rare. Due to potential under-recognization of this disease, it happens to be misdiagnosed, especially on core needle biopsy. We report 3 cases of mediastinal FDCS and provide a literature review to improve better understanding of the tumor and to reduce misdiagnosis. METHODS: Three cases of mediastinal FDCS in our clinic practice were studied, including their core needle biopsy and resected specimens, and those cases reported previously in English literature were retrieved and analyzed. RESULTS: The core needle biopsy of case 1 showed a tumor reminiscent of classical Hodgkin's lymphoma (CHL), while the resected mass was finally diagnosed with FDCS combined with hyaline-vascular Castleman's disease. Both the biopsy and resected tissue of case 2 were constitutive of the clear epithelioid cells with marked atypia. In both cases, definitive diagnoses were not made on core needle biopsy. In case 3, there were some areas morphologically similar to CHL, and some areas contained ovoid to spindle-shaped tumor cells with fascicular pattern. The analysis of 43 cases of mediastinal FDCS showed the age of patients were from 16 to 76 years old, the male to female ratio was 1.5:1, the maximal tumor diameters were 3-17 cm. 18 cases were underwent preoperative biopsy, whereas 15 (83.3%) of which were misdiagnosed initially, often as lymphoma. 32 patients had available follow-up data, the rates of recurrence, metastasis, and mortality were 12.5, 18.8 and 28.1%, respectively. Current limited data suggested no statistical differences between adverse prognosis and gender, age, tumor size, necrosis, or different therapeutics, respectively. CONCLUSIONS: Mediastinal FDCS is a rare malignancy that has yet not been fully understood and been often misdiagnosed, particularly when making a diagnosis on core needle biopsy. Increased awareness of this enigmatic tumor is crucial to avoid diagnostic pitfalls.

Improved detection of BRAF V600E using allele-specific PCR coupled with external and internal controllers.

Although traditional allele-specific PCR (tAS-PCR) is a common screening method for BRAF V600E mutations, its lower amplification specificity and mutation selectivity have limited its clinical applications. We hypothesize that these limitations are associated with the weaker specificities of allele-specific primers and the thermodynamic driving forces of DNA polymerase. We used three strategies to circumvent these limitations, namely, modifying allele-specific primers, introducing a competitive external allele-specific controller (i.e., cAS-PCR), and introducing a referenced internal positive controller in the cAS-PCR (i.e., rcAS-PCR). The amplification sensitivities and specificities were influenced by the position of the artificially introduced mismatched nucleotide in the allele-specific primers. Moreover, both cAS-PCR and rcAS-PCR could detect single-copy BRAF V600E alleles with higher mutation selectivity (0.1%) than tAS-PCR. In addition, cAS-PCR eliminated false-negative results caused by various PCR inhibitors that might be present in the DNA solutions. The rcAS-PCR could also be employed to avoid the false-negative results caused by low-abundance input templates in cAS-PCR. In conclusion, rcAS-PCR provides a rapid, simple, and low-cost method for detecting low levels of the mutated BRAF V600E gene.

Primary follicular dendritic cell sarcoma of the urinary bladder: the first case report and potential diagnostic pitfalls.

BACKGROUND: Extranodal follicular dendritic cell sarcoma (FDCS) is a very rare malignancy with a variable clinical course. It is often not considered and has the potential to result in a misdiagnosis of other common sarcomas or sarcomatoid carcinomas. This is particularly true with the preoperative biopsy specimen, in which the tissue sample is often small. CASE PRESENTATION: A case of FDCS in a 63-year-old woman, arising in the urinary bladder, a previously unreported site, is described. The patient presented with the typical clinical symptoms of a bladder cancer, and the morphology of the tumor was similar to a lymphoepithelioma-like carcinoma, ultimately resulting in it being misdiagnosed. The patient received radical cystectomy, without further radiotherapy or chemotherapy. Two years after operation, a metastatic tumor to the lung was found. The mass of the right main bronchus lumen was frozen and resected through bronchoscopy, and radiotherapy was performed. The patient has lived with the tumor since then. CONCLUSIONS: This paper presents the first FDCS occurring in the urinary bladder with metastasis to the lung and emphasizes potential diagnostic pitfalls.

Evaluation of the diagnostic potential of ex vivo Raman spectroscopy in gastric cancers: fingerprint versus high wavenumber.

The aim of this study was to apply Raman spectroscopy in the high wavenumber (HW) region (2800 to 3000??cm?1) for ex vivo detection of gastric cancer and compare its diagnostic potential with that of the fingerprint (FP) region (800 to 1800??cm?1). Raman spectra were collected in the FP and HW regions to differentiate between normal mucosa (n=38) and gastric cancer (n=37). The distinctive Raman spectral differences between normal and cancer tissues are observed at 853, 879, 1157, 1319, 1338, 1448, and 2932??cm?1 and are primarily related to proteins, lipids, nucleic acids, collagen, and carotenoids in the tissue. In FP and HW Raman spectroscopy for diagnosis of gastric cancer, multivariate diagnostic algorithms based on partial-least-squares discriminant analysis, together with leave-one-sample-out cross validation, yielded diagnostic sensitivities of 94.59% and 81.08%, and specificities of 86.84% and 71.05%, respectively. Receiver operating characteristic analysis further confirmed that the FP region model performance is superior to that of the HW region model. Better differentiation between normal and gastric cancer tissues can be achieved using FP Raman spectroscopy and PLS-DA techniques, but the complementary natures of the FP and HW regions make both of them useful in diagnosis of gastric cancer.

SIRT1-mediated transcriptional regulation of SOX2 is important for self-renewal of liver cancer stem cells.

UNLABELLED: Hepatocellular carcinoma (HCC) is a highly aggressive liver tumor containing cancer stem cells (CSCs), which participate in tumor invasion, therapeutic resistance, and tumor relapse leading to poor outcome and limited therapeutic options. Histone deacetylatase sirtuin 1 (SIRT1) has been shown to be up-regulated in human cancers; however, its role in liver CSCs is unknown. In this study, we explored the biological functions of SIRT1 in liver CSCs. Our data show that SIRT1 is highly expressed in liver CSCs and decreases during differentiation. In addition, high levels of SIRT1 predict a decreased probability of survival in patients with HCC. SIRT1 is responsible for the maintenance of self-renewal and tumorigenicity of liver CSCs, and overexpression of exogenous SIRT1 can restore self-renewal of non-CSCs. We demonstrated that SOX2 is a main downstream regulator of SIRT1-mediated self-renewal and tumorigenicity potential of liver CSCs. Mechanistically, SIRT1 regulates transcription of the SOX2 gene by way of chromatin-based epigenetic changes, which are dependent on DNA methylation. This effect is achieved by alternation of histone modification and interaction with DNA methyltransferase 3A, resulting in hypermethylation of SOX2 promoter. Furthermore, we demonstrated that insulin growth factor signaling plays an important role in maintaining SIRT1 expression through increased SIRT1 protein stability. CONCLUSIONS: These findings highlight the importance of SIRT1 in the biology of liver CSCs and suggest that SIRT1 may serve as a molecular target for HCC therapy. (Hepatology 2016;64:814-827).