Higher expression of SATB2 in hepatocellular carcinoma of African Americans determines more aggressive phenotypes than those of Caucasian Americans

Reduced Expression of SATB2 in Colorectal Cancer and Its Association with Demographic and Clinicopathological Parameters

Special AT-rich sequence-binding protein 2 (SATB2), as a nuclear matrix-associated protein and transcription factor engaged in chromatin remodeling and the regulation of gene expression, plays an important role in growth and development processes. SATB2 has been shown to have tissue-specific expression, also related to some cancers, including colorectal cancer (CRC). The aim of this study was to compare SATB2 gene expression in tumor and matched non-involved colorectal tissues obtained from CRC patients, and to investigate its association with clinicopathological and demographic parameters, as well as patients' overall survival. SATB2 mRNA levels in the tested tissues were assessed by quantitative polymerase chain reaction, while SATB2 protein expression was determined by immunohistochemistry. We found that the average levels of both SATB2 mRNA and protein were significantly lower in tumor specimens than in matched non-involved colon tissues. Moreover, SATB2 immunoreactivity was associated with patients' sex, tumor localization, and grade of differentiation. Lower immunoreactivity of SATB2 protein was noted in high-grade tumors, in women, and in tumors located in the cecum, ascending, and transverse colon. However, the results of the present study did not show an association between SATB2 expression levels and patients' overall survival. Our findings indicate the involvement of impaired SATB2 expression, significantly reduced in high-grading tumors, in the pathogenesis of CRC, while its sex- and localization-specificity should be further elucidated.

Oncogenic Role of SATB2 In Vitro: Regulator of Pluripotency, Self-Renewal, and Epithelial-Mesenchymal Transition in Prostate Cancer

Special AT-rich sequence binding protein-2 (SATB2) is a nuclear matrix protein that binds to nuclear attachment regions and is involved in chromatin remodeling and transcription regulation. In stem cells, it regulates the expression of genes required for maintaining pluripotency and self-renewal and epithelial-mesenchymal transition (EMT). In this study, we examined the oncogenic role of SATB2 in prostate cancer and assessed whether overexpression of SATB2 in human normal prostate epithelial cells (PrECs) induces properties of cancer stem cells (CSCs). The results demonstrate that SATB2 is highly expressed in prostate cancer cell lines and CSCs, but not in PrECs. Overexpression of SATB2 in PrECs induces cellular transformation which was evident by the formation of colonies in soft agar and spheroids in suspension. Overexpression of SATB2 in PrECs also resulted in induction of stem cell markers (CD44 and CD133), pluripotency-maintaining transcription factors (cMYC, OCT4, SOX2, KLF4, and NANOG), CADHERIN switch, and EMT-related transcription factors. Chromatin immunoprecipitation assay demonstrated that SATB2 can directly bind to promoters of BCL-2, BSP, NANOG, MYC, XIAP, KLF4, and HOXA2, suggesting SATB2 is capable of directly regulating pluripotency/self-renewal, cell survival, and proliferation. Since prostate CSCs play a crucial role in cancer initiation, progression, and metastasis, we also examined the effects of SATB2 knockdown on stemness. SATB2 knockdown in prostate CSCs inhibited spheroid formation, cell viability, colony formation, cell motility, migration, and invasion compared to their scrambled control groups. SATB2 knockdown in CSCs also upregulated the expression of E-CADHERIN and inhibited the expression of N-CADHERIN, SNAIL, SLUG, and ZEB1. The expression of SATB2 was significantly higher in prostate adenocarcinoma compared to normal tissues. Overall, our data suggest that SATB2 acts as an oncogenic factor where it is capable of inducing malignant changes in PrECs by inducing CSC characteristics.

Clinical significance of PNO1 as a novel biomarker and therapeutic target of hepatocellular carcinoma

The RNA-binding protein PNO1 plays an essential role in ribosome biogenesis. Recent studies have shown that it is involved in tumorigenesis; however, its role in hepatocellular carcinoma (HCC) is not well understood. The purpose of this study was to examine whether PNO1 can be used as a biomarker of HCC and also examine the therapeutic potential of PNO1 knockout for the treatment of HCC. PNO1 expression was upregulated in HCC and associated with poor prognosis. PNO1 expression was positively associated with tumour stage, lymph node metastasis and poor survival. PNO1 expression was significantly higher in HCC compared to that in fibrolamellar carcinoma or normal tissues. Furthermore, HCC tissues with mutant Tp53 expressed higher PNO1 than those with wild-type Tp53. PNO1 knockout suppressed cell viability, colony formation and EMT of HCC cells. Since activation of Notch signalling pathway promotes HCC, we measured the effects of PNO1 knockout on the components of Notch pathway and its targets. PNO1 knockout suppressed Notch signalling by modulating the expression of Notch ligands and their receptors, and downstream targets. PNO1 knockout also inhibited genes involved in surface adhesion, cell cycle, inflammation and chemotaxis. PNO1 knockout also inhibited colony and spheroid formation, cell migration and invasion, and markers of stem cells, pluripotency and EMT in CSCs. Overall, our data suggest that PNO1 can be used as a diagnostic and prognostic biomarker of HCC, and knockout of PNO1 by CRISPR/Cas9 can be beneficial for the management of HCC by targeting CSCs.

Racial disparities in clinical presentation, surgical procedures, and hospital outcomes among patients with hepatocellular carcinoma in the United States

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the United States (US), with substantial disparities observed in cancer incidence and survival among racial groups. This study provides analyses on race and ethnicity disparities for patients with HCC.

METHODS

This is a cross-sectional analysis of data from the National Inpatient Sample (NIS) between 2011 and 2016, utilizing the STROBE guidelines. Multivariate logistic regression analyses were used to examine the risk-adjusted associations between race and pre-treatment clinical presentation, surgical procedure allocation, and post-treatment hospital outcomes. All clinical parameters were identified using ICD-9-CM and ICD-10-CM diagnosis and procedure codes.

RESULTS

83,876 weighted HCC hospitalizations were reported during the study period. Patient demographics were divided according to NIS racial/ethnic categorization, which includes Caucasian (57.3%), African American (16.9%), Hispanic (15.7%), Asian or Pacific Islanders (9.3%), and Native American (0.8%). Association between greater odds of hospitalization and Elixhauser Comorbidity Index > 4 was significantly higher among Native Americans (aOR=1.79; 95% CI: 1.23-2.73), African Americans (aOR=1.24; 95% CI: 1.12-1.38), and Hispanics (aOR=1.11; 95% CI, 1.01-1.24). Risk-adjusted association between race and receipt of surgical procedures demonstrated that the odds of having surgery was significantly lower for African Americans (aOR=0.64; 95% CI: 0.55-0.73) and Hispanics (aOR=0.70; 95% CI: 0.59-0.82), while significantly higher for Asians/Pacific Islanders (aOR=1.36; 95% CI: 1.28-1.63). Post-operative complications were significantly lower for African Americans (aOR=0.68; 95% CI: 0.55-0.86) while the odds of in-hospital mortality were significantly higher for African Americans (aOR=1.28; 95% CI: 1.11-1.49) and Asians/Pacific Islanders (aOR=1.26; 95% CI: 1.13-1.62).

CONCLUSIONS

After controlling for potential confounders, there were significant racial disparities in pre-treatment presentations, surgical procedure allocations, and post-treatment outcomes among patients with HCC. Further studies are needed to determine the underlying factors for these disparities to develop targeted interventions to reduce these disparities of care.

Riluzole regulates pancreatic cancer cell metabolism by suppressing the Wnt-β-catenin pathway

Most cancer cells rely on aerobic glycolysis to support uncontrolled proliferation and evade apoptosis. However, pancreatic cancer cells switch to glutamine metabolism to survive under hypoxic conditions. Activation of the Wnt/β-catenin pathway induces aerobic glycolysis by activating enzymes required for glucose metabolism and regulating the expression of glutamate transporter and glutamine synthetase. The results demonstrate that riluzole inhibits pancreatic cancer cell growth and has no effect on human pancreatic normal ductal epithelial cells. RNA-seq experiments identified the involvement of Wnt and metabolic pathways by riluzole. Inhibition of Wnt-β-catenin/TCF-LEF pathway by riluzole suppresses the expression of PDK, MCT1, cMyc, AXIN, and CyclinD1. Riluzole inhibits glucose transporter 2 expression, glucose uptake, lactate dehydrogenase A expression, and NAD + level. Furthermore, riluzole inhibits glutamate release and glutathione levels, and elevates reactive oxygen species. Riluzole disrupts mitochondrial homeostasis by inhibiting Bcl-2 and upregulating Bax expression, resulting in a drop of mitochondrial membrane potential. Finally, riluzole inhibits pancreatic cancer growth in KPC (Pdx1-Cre, LSL-Trp53R172H, and LSL-KrasG12D) mice. In conclusion, riluzole can inhibit pancreatic cancer growth by regulating glucose and glutamine metabolisms and can be used to treat pancreatic cancer.

Chronic alcohol exposure induces hepatocyte damage by inducing oxidative stress, SATB2 and stem cell‐like characteristics, and activating lipogenesis

Alcohol is a risk factor for hepatocellular carcinoma (HCC). However, the molecular mechanism by which chronic alcohol consumption contributes to HCC is not well understood. The purpose of the study was to demonstrate the effects of chronic ethanol exposure on the damage of human normal hepatocytes. Our data showed that chronic exposure of hepatocytes with ethanol induced changes similar to transformed hepatocytes that is, exhibited colonies and anchorage‐independent growth. These damaged hepatocytes contained high levels of reactive oxygen species (ROS) and showed induction of the SATB2 gene. Furthermore, damaged hepatocytes gained the phenotypes of CSCs which expressed stem cell markers (CD133, CD44, CD90, EpCAM, AFP and LGR5), and pluripotency maintaining factors (Sox‐2, POU5F1/Oct4 and KLF‐4). Ethanol exposure also induced Nanog, a pluripotency maintaining transcription factor that functions in concert with Oct4 and SOX‐2. Furthermore, ethanol induced expression of EMT‐related transcription factors (Snail, Slug and Zeb1), N‐Cadherin, and inhibited E‐cadherin expression in damaged hepatocytes. Ethanol enhanced recruitment of SATB2 to promoters of Bcl‐2, Nanog, c‐Myc, Klf4 and Oct4. Ethanol also induced activation of the Wnt/TCF‐LEF1 pathway and its targets (Bcl‐2, Cyclin D1, AXIN2 and Myc). Finally, ethanol induced hepatocellular steatosis, SREBP1 transcription, and modulated the expression of SREBP1c, ACAC, ACLY, FASN, IL‐1β, IL‐6, TNF‐α, GPC3, FLNB and p53. These data suggest that chronic alcohol consumption may contribute towards the development of HCC by damaging normal hepatocytes with the generation of inflammatory environment, induction of SATB2, stem cell‐like characteristics, and cellular steatosis.

Ethanol exposure of human pancreatic normal ductal epithelial cells induces EMT phenotype and enhances pancreatic cancer development in KC (Pdx1-Cre and LSL-KrasG12D ) mice

Alcohol is a risk factor for pancreatic cancer. However, the molecular mechanism by which chronic alcohol consumption influences pancreatic cancer development is not well understood. We have recently demonstrated that chronic ethanol exposure of pancreatic normal ductal epithelial cells (HPNE) induces cellular transformation by generating cancer stem cells (CSCs). Here, we examined whether chronic ethanol treatment induces epithelial–mesenchymal transition in HPNE cells and promotes pancreatic cancer development in KC (Pdx1‐Cre, and LSL‐Kras^G12D) mice. Our data demonstrate that chronic ethanol exposure of HPNE cells induces SATB2 gene and those cells became highly motile. Ethanol treatment of HPNE cells results in downregulation of E‐Cadherin and upregulation of N‐Cadherin, Snail, Slug, Zeb1, Nanog and BMI‐1. Suppression of SATB2 expression in ethanol‐transformed HPNE cells inhibits EMT phenotypes. KC mice fed with an ethanol‐containing diet show enhanced pancreatic cancer growth and development than those fed with a control diet. Pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of stem cell markers (CD133, CD44, CD24), pluripotency‐maintaining factors (cMyc, KLF4, SOX‐2, and Oct‐4), N‐Cadherin, EMT‐transcription factors (Snail, Slug, and Zeb1), and lower expression of E‐cadherin than those isolated from mice fed with a control diet. Furthermore, pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of inflammatory cytokines (TNF‐α, IL‐6, and IL‐8) and PTGS‐2 (COX‐2) gene than those isolated from mice fed with a control diet. These data suggest that chronic alcohol consumption may contribute to pancreatic cancer development by generating inflammatory signals and CSCs.

Black Patients With Cirrhosis Have Higher Mortality and Lower Transplant Rates: Results From a Metropolitan Cohort Study

BACKGROUND AND AIMS

Estimates of racial disparity in cirrhosis have been limited by lack of large-scale, longitudinal data, which track patients from diagnosis to death and/or transplant.

APPROACH AND RESULTS

We analyzed a large, metropolitan, population-based electronic health record data set from seven large health systems linked to the state death registry and the national transplant database. Multivariate competing risk analyses, adjusted for sex, age, insurance status, Elixhauser score, etiology of cirrhosis, HCC, portal hypertensive complication, and Model for End-Stage Liver Disease-Sodium (MELD-Na), examined the relationship between race, transplant, and cause of death as defined by blinded death certificate review. During the study period, 11,277 patients met inclusion criteria, of whom 2,498 (22.2%) identified as Black. Compared to White patients, Black patients had similar age, sex, MELD-Na, and proportion of alcohol-associated liver disease, but higher comorbidity burden, lower rates of private insurance, and lower rates of portal hypertensive complications. Compared to White patients, Black patients had the highest rate all-cause mortality and non-liver-related death and were less likely to be listed or transplanted (P < 0.001 for all). In multivariate competing risk analysis, Black patients had a 26% increased hazard of liver-related death (subdistribution HR, 1.26; 95% CI, [1.15-1.38]; P < 0.001).

CONCLUSIONS

Black patients with cirrhosis have discordant outcomes. Further research is needed to determine how to address these real disparities in the field of hepatology.

Aberrant expression of SATB2, CDX2, CDH17 and CK20 in hepatocellular carcinoma: a pathological, clinical and outcome study

AIMS

Data regarding expression of intestinal markers in hepatocellular carcinoma (HCC) are limited. We determined the clinicopathological associations of cytokeratin (CK)19, a progenitor liver epithelial cell marker as well as biliary epithelial marker, and intestinal immunohistochemical markers expression in HCC and assessed their prognostic value.

METHODS AND RESULTS

Tissue sections and/or tissue microarrays (TMAs) from 202 known HCCs were immunostained using CK19, CK20, CDH17, CDX2 and SATB2 antibodies. Haematoxylin and eosin (H&E)-stained slides were reviewed for tumour grading. Clinical and oncological outcomes were retrieved. Associations of staining with clinicopathological features and survival outcomes were evaluated. CK19, CK20, CDH17, CDX2 and SATB2 were positive in 12.8, 5.4, 10.3, 8.6 and 59.9%, respectively. All but SATB2 were strongly associated with higher tumour grade and AFP levels > 400 ng/ml (P < 0.05). CK19-positive HCC were more likely to express CDX2 (P = 0.001), CDH17 (P < 0.001) and/or CK20 (P = 0.012). CK20, CDX2 and CDH17 co-expression was seen in five cases (2.5%). CK19 and SATB2 positivity, tumour size ≥ 5 cm, background cirrhosis, AFP > 400 ng/ml and having no treatment were associated with decreased overall survival by log-rank test and univariable proportional hazards regression. However, in a multivariable model, CK19 and SATB2 positivity were not independent predictors of decreased survival while their association with known poor prognosticators in HCC was evident.

CONCLUSIONS

HCC can express markers of intestinal differentiation. This phenotypical aberrancy correlates with variable clinicopathological parameters, some of which are independent predictors of poor survival.

SATB2 overexpression promotes oral squamous cell carcinoma progression by up-regulating NOX4

While atypical expression of special AT-rich sequence-binding protein 2 (SATB2) has been approved associated with tumor progression, metastasis and unfavourable prognosis in various carcinomas. However, in oral squamous cell carcinoma (OSCC), both the expressive state and associated functions of SATB2's are still undefined. Here we show that, in clinical samples from a retrospective cohort of 58 OSCC patients, high expression of SATB2 is associated with poor prognosis of OSCC patients. In this study, we investigated SATB2 is highly expressed in OSCC tissues and cell lines, which can promote OSCC cells' proliferation, migration, invasion and tumor growth. According to sequencing results based on previous literature, we identified NOX4 is a bona fide downstream target of SATB2, when it was knockdown, OSCC's proliferation can be partially suppressed. Furthermore, NOX4 knockdown inhibits tumorigenicity, which can be rescued partially by ectopic expression of SATB2 in HNSCC cell line, and vice versa. Collectively, our findings not only indicate overexpression of SATB2 triggers the proliferative, migratory and invasive mechanisms which are important in the malignant phenotype of OSCC, but also identify NOX4 as the downstream gene for SATB2. These findings indicate that SATB2 may play a key role in OSCC tumorigenicity and may be a future target for the development of new therapeutic regimens.

SATB2: A versatile transcriptional regulator of craniofacial and skeleton development, neurogenesis and tumorigenesis, and its applications in regenerative medicine

SATB2 (special AT-rich sequence-binding protein 2) is a member of the special AT-rich binding protein family. As a transcription regulator, SATB2 mainly integrates higher-order chromatin organization. SATB2 expression appears to be tissue- and stage-specific, and is governed by several cellular signaling molecules and mediators. Expressed in branchial arches and osteoblast-lineage cells, SATB2 plays a significant role in craniofacial pattern and skeleton development. In addition to regulating osteogenic differentiation, SATB2 also displays versatile functions in neural development and cancer progression. As an osteoinductive factor, SATB2 holds great promise in improving bone regeneration toward bone defect repair. In this review, we have summarized our current understanding of the physiological and pathological functions of SATB2 in craniofacial and skeleton development, neurogenesis, tumorigenesis and regenerative medicine.

SATB2 is a novel biomarker and therapeutic target for cancer

Several studies have confirmed the involvement of cancer stem cells (CSC) in tumour progression, metastasis, drug resistance and cancer relapse. SATB2 (special AT-rich binding protein-2) acts as a transcriptional co-factor and modulates chromatin architecture to regulate gene expression. The purpose of this review was to discuss the pathophysiological roles of SATB2 and assess whether it could be used as a therapeutic target for cancer. SATB2 modulated the expression of those genes which regulated pluripotency and self-renewal. Overexpression of SATB2 gene in normal epithelial cells was shown to induce transformation, as a result transformed cells gained CSC's characteristics by expressing stem cell markers and pluripotency maintaining factors, suggesting its role as an oncogene. In addition, SATB2 induced epithelial-mesenchymal transition (EMT) and metastasis. Interestingly, the expression of SATB2 was positively correlated with the activation of β-catenin/TCF-LEF pathway. Furthermore, SATB2 silencing inhibited EMT and their positive regulators, and tumour growth, and suppressed the expression of stem cell markers, pluripotency maintaining factors, cell cycle and cell survival genes, and TCF/LEF targets. Based on the cancer genome atlas (TCGA) expression data and published papers, SATB2 alone or in combination with other proteins could be used a diagnostic biomarker for cancer. Although there is no pharmacological inhibitor of SATB2, studies using genetic approaches suggest that SATB2 could be a potential target for cancer treatment and prevention.

Hepatocellular carcinomas can be Special AT-rich sequence-binding protein 2 positive: an important diagnostic pitfall

Special AT-rich sequence-binding protein 2 (SATB2) is a sensitive and specific marker for tumors originating with the colon and appendix. It is now commonly used in surgical pathology, while working up carcinomas of unknown primary. We had anecdotally encountered occasional hepatocellular carcinomas (HCCs) that were SATB2 positive. Immunohistochemical expression of SATB2 in HCC has not yet been examined in detail. In this study, we evaluated SATB2 expression in 46 HCCs. Nineteen (41%) of 46 HCCs were positive for SATB2. SATB2 expression in HCCs was more commonly seen in poorly differentiated tumors (11 of 13 cases, 85%) than well and moderately differentiated tumors (8 of 33 cases, 24%), p value = 0.0001. No other statistically significant correlations were observed (p > 0.05). There were no other statistically significant correlations between SATB2 expression and age, gender, background liver disease, and cirrhosis (p > 0.05). Results of our study show that a significant subset (41%) of HCCs can be SATB2 positive. Awareness of this phenomenon is important as SATB2 expression in a liver tumor does not completely exclude a diagnosis of HCC.

Assessment of risk factors, and racial and ethnic differences in hepatocellular carcinoma

Despite improved screening and surveillance guidelines, significant race/ethnicity‐specific disparities in hepatocellular carcinoma (HCC) continue to exist and disproportionately affect minority and disadvantaged populations. This trend indicates that social determinants, genetic, and environmental factors are driving the epidemic at the population level. Race and geography had independent associations with risk of mortality among patients with HCC. The present review discusses the risk factors and issues related to disparities in HCC. The underlying etiologies for these disparities are complex and multifactorial. Some of the risk factors for developing HCC include hepatitis B (HBV) and hepatitis C (HCV) viral infection, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, smoking and alcohol consumption. In addition, population genetics; socioeconomic and health care access; treatment and prevention differences; and genetic, behavioral, and biological influences can contribute to HCC. Acculturation of ethnic minorities, insurance status, and access to health care may further contribute to the observed disparities in HCC. By increasing awareness, better modalities for screening and surveillance, improving access to health care, and adapting targeted preventive and therapeutic interventions, disparities in HCC outcomes can be reduced or eliminated.

Higher expression of SATB2 in hepatocellular carcinoma of African Americans determines more aggressive phenotypes than those of Caucasian Americans

In the United States, Hepatocellular Carcinoma (HCC) incidence has tripled over the past two decades. The disease has disproportionately affected minority and disadvantaged populations. The purpose of this study was to examine the expression of SATB2 gene in HCC cells derived from African Americans (AA) and Caucasian Americans (CA) and assess its oncogenic potential by measuring cell viability, spheroid formation, epithelial‐mesenchymal transition (EMT), stem cell markers and pluripotency maintaining factors in cancer stem cells (CSCs). We compared the expression of SATB2 in human primary hepatocytes, HCC cells derived from AA and CA, and HCC CSCs. Hepatocellular carcinoma cells derived from AA expressed the higher level of SATB2 than those from CA. By comparison, normal human hepatocytes did not express SATB2. Higher expression of SATB2 in HCC cells from AA was associated with greater growth rate, cell viability, colony formation and EMT characteristics than those from CA. Knockout of SATB2 in CSCs by Crispr/Cas9 technique significantly inhibited the expression of SATB2 gene, stem cell markers (CD24, CD44 and CD133), pluripotency maintaining factors (c‐Myc, KLF4, SOX2 and OCT4), and EMT compared with non‐targeting control group. The expression of SATB2 was negatively correlated with miR34a. SATB2 rescued the miR‐34a‐mediated inhibition of CSC's viability. These data suggest that SATB2 is an oncogenic factor, and its higher expression may explain the disparity in HCC outcomes among AA.