Dual Inhibition of CDK4/6 and XPO1 Induces Senescence With Acquired Vulnerability to CRBN-Based PROTAC Drugs.

BACKGROUND & AIMS: Despite the increasing number of treatment options available for liver cancer, only a small proportion of patients achieve long-term clinical benefits. Here, we aim to develop new therapeutic approaches for liver cancer. METHODS: A compound screen was conducted to identify inhibitors that could synergistically induce senescence when combined with cyclin-dependent kinase (CDK) 4/6 inhibitor. The combination effects of CDK4/6 inhibitor and exportin 1 (XPO1) inhibitor on cellular senescence were investigated in a panel of human liver cancer cell lines and multiple liver cancer models. A senolytic drug screen was performed to identify drugs that selectively killed senescent liver cancer cells. RESULTS: The combination of CDK4/6 inhibitor and XPO1 inhibitor synergistically induces senescence of liver cancer cells in vitro and in vivo. The XPO1 inhibitor acts by causing accumulation of RB1 in the nucleus, leading to decreased E2F signaling and promoting senescence induction by the CDK4/6 inhibitor. Through a senolytic drug screen, cereblon (CRBN)-based proteolysis targeting chimera (PROTAC) ARV-825 was identified as an agent that can selectively kill senescent liver cancer cells. Up-regulation of CRBN was a vulnerability of senescent liver cancer cells, making them sensitive to CRBN-based PROTAC drugs. Mechanistically, we find that ubiquitin specific peptidase 2 (USP2) directly interacts with CRBN, leading to the deubiquitination and stabilization of CRBN in senescent liver cancer cells. CONCLUSIONS: Our study demonstrates a striking synergy in senescence induction of liver cancer cells through the combination of CDK4/6 inhibitor and XPO1 inhibitor. These findings also shed light on the molecular processes underlying the vulnerability of senescent liver cancer cells to CRBN-based PROTAC therapy.

Inducing and exploiting vulnerabilities for the treatment of liver cancer.

Liver cancer remains difficult to treat, owing to a paucity of drugs that target critical dependencies1,2; broad-spectrum kinase inhibitors such as sorafenib provide only a modest benefit to patients with hepatocellular carcinoma3. The induction of senescence may represent a strategy for the treatment of cancer, especially when combined with a second drug that selectively eliminates senescent cancer cells (senolysis)4,5. Here, using a kinome-focused genetic screen, we show that pharmacological inhibition of the DNA-replication kinase CDC7 induces senescence selectively in liver cancer cells with mutations in TP53. A follow-up chemical screen identified the antidepressant sertraline as an agent that kills hepatocellular carcinoma cells that have been rendered senescent by inhibition of CDC7. Sertraline suppressed mTOR signalling, and selective drugs that target this pathway were highly effective in causing the apoptotic cell death of hepatocellular carcinoma cells treated with a CDC7 inhibitor. The feedback reactivation of mTOR signalling after its inhibition6 is blocked in cells that have been treated with a CDC7 inhibitor, which leads to the sustained inhibition of mTOR and cell death. Using multiple in vivo mouse models of liver cancer, we show that treatment with combined inhibition of of CDC7 and mTOR results in a marked reduction of tumour growth. Our data indicate that exploiting an induced vulnerability could be an effective treatment for liver cancer.

Novel quantitative immunohistochemistry method using histone H3, family 3B as the internal reference standard for measuring human epidermal growth factor receptor 2 expression in breast cancer.

BACKGROUND: Immunohistochemistry (IHC) is an essential technique in surgical and clinical pathology for detecting diagnostic, prognostic, and predictive biomarkers for personalized cancer therapy. However, the lack of standardization and reference controls results in poor reproducibility, and a reliable tool for IHC quantification is urgently required. The objective of this study was to describe a novel approach in which H3F3B (histone H3, family 3B) can be used as an internal reference standard to quantify protein expression levels using IHC. METHODS: The authors enrolled 89 patients who had human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). They used a novel IHC-based assay to measure protein expression using H3F3B as the internal reference standard. H3F3B was uniformly expressed at the protein level in all tumor regions in cancer tissues. HER2 expression levels were measured with the H-score using HALO software. RESULTS: Kaplan-Meier analysis indicated that, among patients who had HER2-positive BC in The Cancer Genome Atlas data set and the authors' data set, the subgroup with low HER2 expression had a significantly better prognosis than the subgroup with high HER2 expression. Furthermore, the authors observed that HER2 expression levels were precisely evaluated using the proposed method, which can classify patients who are at higher risk of HER2-positive BC to receive trastuzumab-based adjuvant therapy. Dual-color IHC with H3F3B is an excellent tool for internal and external quality control of HER2 expression assays. CONCLUSIONS: The proposed IHC-based quantification method accurately assesses HER2 expression levels and provides insights for predicting clinical prognosis in patients with HER2-positive BC who receive trastuzumab-based adjuvant therapy.

Symptom clusters and network analysis of patients with intermediate and advanced liver cancer treated with targeted immunotherapy.

BACKGROUND: This study aims to identify symptom clusters in patients with intermediate and advanced liver cancer receiving targeted immunotherapy, focusing on core and bridge symptoms to establish a foundation for precise symptom management. METHODS: This study used a cross-sectional survey and utilized convenience sampling from May 2023 to January 2024 at a third-class hospital in Shanghai, China. The severity of symptoms in liver cancer patients during treatment was evaluated using the Memorial Symptom Assessment Scale. Network analysis was employed to depict the interrelation of symptom clusters and identify core and bridge symptoms. RESULTS: The symptoms were classified by severity into five clusters: oral, gastrointestinal, fatigue-related, body image, and pain-sleep. Within the symptom network, the core symptoms were pain, "I don't look like myself," and nausea, while the critical bridge symptoms included pain, itching, and feeling bloated. The strongest connections were observed between nausea and vomiting, followed by taste changes and dry mouth, as well as weight loss and "I don't look like myself." CONCLUSION: In patients receiving targeted immunotherapy for intermediate and advanced liver cancer, multiple symptoms can emerge simultaneously, forming interconnected clusters. By identifying and intervening in core and bridge symptoms, personalized management strategies can be developed to relieve other symptoms and disrupt connections between symptom clusters, thereby enhancing symptom management efficacy. This study has significant clinical and research implications, offering new insights to improve patients' quality of life and treatment outcomes.

PPARγ Coactivator-1α Suppresses Metastasis of Hepatocellular Carcinoma by Inhibiting Warburg Effect by PPARγ-Dependent WNT/ß-Catenin/Pyruvate Dehydrogenase Kinase Isozyme 1 Axis.

BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1α (PGC1α) is a key regulator of mitochondrial biogenesis and respiration. PGC1α is involved in the carcinogenesis, progression, and metabolic state of cancer. However, its role in the progression of hepatocellular carcinoma (HCC) remains unclear. APPROACH AND RESULTS: In this study, we observed that PGC1α was down-regulated in human HCC. A clinical study showed that low levels of PGC1α expression were correlated with poor survival, vascular invasion, and larger tumor size. PGC1α inhibited the migration and invasion of HCC cells with both in vitro experiments and in vivo mouse models. Mechanistically, PGC1α suppressed the Warburg effect through down-regulation of pyruvate dehydrogenase kinase isozyme 1 (PDK1) mediated by the WNT/ß-catenin pathway, and inhibition of the WNT/ß-catenin pathway was induced by activation of PPARγ. CONCLUSIONS: Low levels of PGC1α expression indicate a poor prognosis for HCC patients. PGC1α suppresses HCC metastasis by inhibiting aerobic glycolysis through regulating the WNT/ß-catenin/PDK1 axis, which depends on PPARγ. PGC1α is a potential factor for predicting prognosis and a therapeutic target for HCC patients.

Evaluation of nuclear PGAM2 value in hepatocellular carcinoma prognosis.

Phosphoglycerate mutase (PGAM) is a critical enzyme in glycolysis. PGAM2 is abundant in several types of tissues and malignant tumours. However, there is limited information regarding their clinicopathological significance in dysplastic nodules and hepatocellular carcinoma (HCC). This study aims to investigate the prognostic value of PGAM2 as a new biomarker for HCC. The PGAM2 expression level was evaluated by immunohistochemistry in liver cirrhosis (n = 10), low-grade dysplastic nodules (n = 15), high-grade dysplastic nodules (n = 15) and HCCs (n = 20) and 178 pairs of HCC and adjacent peritumoral liver tissues. We selected X-tile software for counting cut-point based on the outcomes for prognosis analysis, and used Kaplan-Meier analysis and Cox regression analysis can assess the prognosis of clinicopathologic parameters. Nuclear PGAM2 was significantly overexpressed in peritumoral liver tissues compared with HCC tissues (P = 0.0010). Kaplan-Meier analyses of 178 HCC samples revealed that nuclear PGAM2's high expression level, but not cytoplasmic PGAM2, was significantly related to good overall survival rate (OS). In addition, univariate and multivariate Cox analyses indicated nuclear PGAM2 expression could be regarded as valuable predictors for OS in HCC. PGAM2 was highly expressed in HCC tissues than liver cirrhosis tissues, and nuclear PGAM2's high expression might demonstrate HCC patients have poor postoperative results. Thus, nuclear PGAM2 can be regarded as valuable predictors for OS in HCC patients after surgery.

Post-hepatectomy liver failure prediction and prevention: Development of a nomogram containing postoperative anticoagulants as a risk factor.

INTRODUCTION AND OBJECTIVES: Posthepatectomy liver failure (PHLF) is a serious complication after hepatectomy, and its effective methods for preoperative prediction are lacking. Here, we aim to identify predictive factors and build a nomogram to evaluate patients' risk of developing PHLF. PATIENTS AND METHODS: A retrospective review of a training cohort, including 199 patients who underwent hepatectomy at the Shanghai Eastern Hepatobiliary Surgery Hospital, was conducted. Independent risk variables for PHLF were identified using multivariate analysis of perioperative variables, and a nomogram was used to build a predictive model. To test the predictive power, a prospective study in which a validation cohort of 71 patients was evaluated using the nomogram. The prognostic value of this nomogram was evaluated by the C-index. RESULTS: Independent risk variables for PHLF were identified from perioperative variables. In multivariate analysis of the training cohort, tumor number, Pringle maneuver, blood loss, preoperative platelet count, postoperative ascites and use of anticoagulant medications were determined to be key risk factors for the development of PHLF, and they were selected for inclusion in our nomogram. The nomogram showed a 0.911 C-index for the training cohort. In the validation cohort, the nomogram also showed good prognostic value for predicting PHLF. The validation cohort was used with similarly successful results to evaluate risk in two previously published study models with calculated C-indexes of 0.718 and 0.711. CONCLUSION: Our study establishes for the first time a novel nomogram that can be used to identify patients at risk of developing PHLF.

Phosphoglucomutase 1 inhibits hepatocellular carcinoma progression by regulating glucose trafficking.

Glycogen metabolism commonly altered in cancer is just beginning to be understood. Phosphoglucomutase 1 (PGM1), the first enzyme in glycogenesis that catalyzes the reversible conversion between glucose 1-phosphate (G-1-P) and glucose 6-phosphate (G-6-P), participates in both the breakdown and synthesis of glycogen. Here, we show that PGM1 is down-regulated in hepatocellular carcinoma (HCC), which is associated with the malignancy and poor prognosis of HCC. Decreased PGM1 expression obstructed glycogenesis pathway, which leads to the increased flow of glucose into glycolysis, thereby promoting tumor cell proliferation and HCC development. The loss of forkhead box protein J2 (FOXJ2), at least partly due to low genomic copy number in HCC, releases cellular nucleic acid-binding protein (CNBP), a nucleic acid chaperon, to bind to and promote G-quadruplex formation in PGM1 promoter and therefore decreases PGM1 expression. In addition, integrated analyses of PGM1 and FOXJ2 expression provide a better prediction for the malignance and prognosis of HCC. This study establishes a tumor-suppressive role of PGM1 by regulating glucose trafficking and uncovers a novel regulatory mechanism of PGM1 expression.

CDK12 inhibition mediates DNA damage and is synergistic with sorafenib treatment in hepatocellular carcinoma.

OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and a major leading cause of cancer-related deaths worldwide. Several therapeutic options like sorafenib and regorafenib provide only modest survival benefit to patients with HCC. This study aims to identify novel druggable candidate genes for patients with HCC. DESIGN: A non-biased CRISPR (clustered regularly interspaced short palindromic repeats) loss-of-function genetic screen targeting all known human kinases was performed to identify vulnerabilities of HCC cells. Whole-transcriptome sequencing (RNA-Seq) and bioinformatics analyses were performed to explore the mechanisms of the action of a cyclin-dependent kinase 12 (CDK12) inhibitor in HCC cells. Multiple in vitro and in vivo assays were used to study the synergistic effects of the combination of CDK12 inhibition and sorafenib. RESULTS: We identify CDK12 as critically required for most HCC cell lines. Suppression of CDK12 using short hairpin RNAs (shRNAs) or its inhibition by the covalent small molecule inhibitor THZ531 leads to robust proliferation inhibition. THZ531 preferentially suppresses the expression of DNA repair-related genes and induces strong DNA damage response in HCC cell lines. The combination of THZ531 and sorafenib shows striking synergy by inducing apoptosis or senescence in HCC cells. The synergy between THZ531 and sorafenib may derive from the notion that THZ531 impairs the adaptive responses of HCC cells induced by sorafenib treatment. CONCLUSION: Our data highlight the potential of CDK12 as a drug target for patients with HCC. The striking synergy of THZ531 and sorafenib suggests a potential combination therapy for this difficult to treat cancer.

Oncofetal HLF transactivates c-Jun to promote hepatocellular carcinoma development and sorafenib resistance.

BACKGROUND AND AIMS: The unique expression pattern makes oncofetal proteins ideal diagnostic biomarkers and therapeutic targets in cancer. However, few oncofetal proteins have been identified and entered clinical practice. METHODS: Fetal liver, adult liver and hepatocellular carcinoma (HCC) tissues were employed to assess the expression of hepatic leukaemia factor (HLF). The impact of HLF on HCC onset and progression was investigated both in vivo and in vitro. The association between HLF and patient prognosis was determined in patient cohorts. The correlation between HLF expression and sorafenib benefits in HCC was further evaluated in patient cohorts and patient-derived xenografts (PDXs). RESULTS: HLF is a novel oncofetal protein which is reactivated in HCC by SOX2 and OCT4. Functional studies revealed that HLF transactivates c-Jun to promote tumour initiating cell (TIC) generation and enhances TIC-like properties of hepatoma cells, thus driving HCC initiation and progression. Consistently, our clinical investigations elucidated the association between HLF and patient prognosis and unravelled the close correlation between HLF levels and c-Jun expression in patient HCCs. Importantly, HLF/c-Jun axis determines the responses of hepatoma cells to sorafenib treatment, and interference of HLF abrogated c-Jun activation and enhanced sorafenib response. Analysis of patient cohorts and PDXs further suggests that HLF/c-Jun axis might serve as a biomarker for sorafenib benefits in HCC patients. CONCLUSIONS: Our findings uncovered HLF as a novel oncofetal protein and revealed the crucial role of the HLF/c-Jun axis in HCC development and sorafenib response, rendering HLF as an optimal target for the prevention and intervention of HCC.

Overexpression of MTHFD1 in hepatocellular carcinoma predicts poorer survival and recurrence.

Aim: MTHFD1 was the enzyme providing one-carbon derivatives of tetrahydrofolate. We sought to investigate the impact of MTHFD1 on hepatocellular carcinoma (HCC). Methods: Bioinformatic analysis, western blot and immunohistochemistry were conducted to detect MTHFD1 expression in HCC. The relationships between MTHFD1 and prognosis of 172 HCCs were analyzed by Kaplan-Meier method and Cox proportional hazards model. Results: High MTHFD1 expression in HCC represented poor prognosis (overall survival p = 0.025; time to recurrence p = 0.044). Combining MTHFD1 with serum AFP, survival analysis demonstrated the prognosis of the MTHFD1 low expression and AFP ≤20 ng/ml group was better than that of the MTHFD1 high expression or AFP >20 ng/ml group and the MTHFD1 high expression and AFP >20 ng/ml group (overall survival p < 0.0001; time to recurrence p < 0.0001). Conclusion: High MTHFD1 expression in HCC indicated poorer prognosis. Combining MTHFD1 with serum AFP improved the accuracy of prognostic prediction.

Phospho-ERK is a biomarker of response to a synthetic lethal drug combination of sorafenib and MEK inhibition in liver cancer.

BACKGROUND & AIMS: Treatment of liver cancer remains challenging because of a paucity of drugs that target critical dependencies. Sorafenib is a multikinase inhibitor that is approved as the standard therapy for patients with advanced hepatocellular carcinoma, but it only provides limited survival benefit. In this study we aimed to identify potential combination therapies to improve the clinical response to sorafenib. METHODS: To investigate the cause of the limited therapeutic effect of sorafenib, we performed a CRISPR-Cas9 based synthetic lethality screen to search for kinases whose knockout synergizes with sorafenib. Synergistic effects of sorafenib and selumetinib on cell apoptosis and phospho-ERK (p-ERK) were analyzed by caspase-3/7 apoptosis assay and western blot, respectively. p-ERK was measured by immunochemical analysis using a tissue microarray containing 78 liver cancer specimens. The in vivo effects of the combination were also measured in two xenograft models. RESULT: We found that suppression of ERK2 (MAPK1) sensitizes several liver cancer cell lines to sorafenib. Drugs inhibiting the MEK (MEK1/2 [MAP2K1/2]) or ERK (ERK1/2 [MAPK1/3]) kinases reverse unresponsiveness to sorafenib in vitro and in vivo in a subset of liver cancer cell lines characterized by high levels of active p-ERK, through synergistic inhibition of ERK kinase activity. CONCLUSION: Our data provide a combination strategy for treating liver cancer and suggest that tumors with high basal p-ERK levels, which are seen in approximately 30% of liver cancers, are most likely to benefit from such combinatorial treatment. LAY SUMMARY: Sorafenib is approved as the standard therapy for patients with advanced hepatocellular carcinoma, but only provides limited survival benefit. Herein, we found that inhibition of the kinase ERK2 increases the response to sorafenib in liver cancer. Our data indicate that a combination of sorafenib and a MEK inhibitor is most likely to be effective in tumors with high basal phospho-ERK levels.

Regulator of Calcineurin 1 Gene Isoform 4, Down-regulated in Hepatocellular Carcinoma, Prevents Proliferation, Migration, and Invasive Activity of Cancer Cells and Metastasis of Orthotopic Tumors by Inhibiting Nuclear Translocation of NFAT1.

BACKGROUND & AIMS: Individuals with Down syndrome have a low risk for many solid tumors, prompting the search for tumor suppressor genes on human chromosome 21 (HSA21). We aimed to identify and explore potential mechanisms of tumor suppressors on HSA21 in hepatocellular carcinoma (HCC). METHODS: We compared expression of HSA21 genes in 14 pairs of primary HCC and adjacent noncancer liver tissues using the Affymetrix HG-U133 Plus 2.0 array (Affymetrix, Santa Clara, CA). HCC tissues and adjacent normal liver tissues were collected from 108 patients at a hospital in China for real-time polymerase chain reaction and immunohistochemical analyses; expression levels of regulator of calcineurin 1 (RCAN1) isoform 4 (RCAN1.4) were associated with clinical features. We overexpressed RCAN1.4 from lentiviral vectors in MHCC97H and HCCLM3 cells and knocked expression down using small interfering RNAs in SMMC7721 and Huh7 cells. Cells were analyzed in proliferation, migration, and invasion assays. HCC cells that overexpressed RCAN1.4 or with RCAN1.4 knockdown were injected into livers or tail veins of nude mice; tumor growth and numbers of lung metastases were quantified. We performed bisulfite pyrosequencing and methylation-specific polymerase chain reaction analyses to analyze CpG island methylation. We measured phosphatase activity of calcineurin in HCC cells. RESULTS: RCAN1.4 mRNA and protein levels were significantly decreased in primary HCC compared with adjacent noncancer liver tissues. Reduced levels of RCAN1.4 mRNA were significantly associated with advanced tumor stages, poor differentiation, larger tumor size, and vascular invasion. Kaplan-Meier survival analysis showed that patients with HCCs with lower levels of RCAN1.4 mRNA had shorter time of overall survival and time to recurrence than patients whose tumors had high levels of RCAN1.4 mRNA. In HCC cell lines, expression of RCAN1.4 significantly reduced proliferation, migration, and invasive activity. HCC cells that overexpressed RCAN1.4 formed smaller xenograft tumors, with fewer metastases and blood vessels, than control HCC cells. In HCC cells, RCAN1.4 inhibited expression of insulin-like growth factor 1 and vascular endothelial growth factor A by reducing calcineurin activity and blocking nuclear translocation of nuclear factor of activated T cells (NFAT1). HCC cells incubated with the calcineurin inhibitor cyclosporin A had decreased nuclear level of NFAT1. HCC cells had hypermethylation of a CpG island in the 5' regulatory region of RCAN1.4, which reduced its expression. CONCLUSIONS: RCAN1.4 is down-regulated in HCC tissues, compared with non-tumor liver tissues. RCAN1.4 prevents cell proliferation, migration, and invasion in vitro; overexpressed RCAN1.4 in HCC cells prevents growth, angiogenesis, and metastases of xenograft tumors by inhibiting calcineurin activity and nuclear translocation of NFAT1.

Shp2 promotes liver cancer stem cell expansion by augmenting ß-catenin signaling and predicts chemotherapeutic response of patients.

Src-homology 2 domain-containing phosphatase 2 (Shp2) has been reported to play an important role in the maintenance and self-renewal of embryonic and adult stem cells, but its role in cancer stem cells (CSCs) remains obscure. Herein, we observed high expression of Shp2 in both chemoresistant hepatocellular carcinomas (HCCs) and recurrent HCCs from patients. A remarkable increase of Shp2 was detected in sorted epithelial cell adhesion molecule-positive or cluster of differentiation 133-positive liver CSCs and in CSC-enriched hepatoma spheroids from patients. Up-regulated Shp2 facilitated liver CSC expansion by promoting the dedifferentiation of hepatoma cells and enhancing the self-renewal of liver CSCs. Mechanistically, Shp2 dephosphorylated cell division cycle 73 in the cytosol of hepatoma cells, and the dephosphorylated cell division cycle 73 bound ß-catenin and facilitated the nuclear translocation of ß-catenin, which promoted the dedifferentiation of hepatoma cells. Shp2 increased ß-catenin accumulation by inhibiting glycogen synthase kinase 3ß-mediated ß-catenin degradation in liver CSCs, thereby enhancing the self-renewal of liver CSCs. Blockage of ß-catenin abolished the discrepancy in liver CSC proportion and the self-renewal capacity between Shp2-depleted hepatoma cells and control cells, which further confirmed that ß-catenin is required in Shp2-promoted liver CSC expansion. More importantly, HCC patients with low Shp2 levels benefited from transcatheter arterial chemoembolization or sorafenib treatment, but patients with high Shp2 expression did not, indicating the significance of Shp2 in personalized HCC therapy. CONCLUSION: Shp2 could promote HCC cell dedifferentiation and liver CSC expansion by amplifying ß-catenin signaling and may be useful in predicting patient response to chemotherapeutics. (Hepatology 2017;65:1566-1580).

Loss of FBP1 facilitates aggressive features of hepatocellular carcinoma cells through the Warburg effect.

Reprogrammed metabolism has been identified as an emerging hallmark in cancer cells. It has been demonstrated that fructose-1, 6-bisphosphatase 1 (FBP1) as a rate-limiting enzyme in gluconeogenesis plays critical roles in tumor initiation and progression in several cancer types. However, function of FBP1 in hepatocellular carcinoma (HCC) is still not clear. In this study, we observed that the expression of FBP1 was obviously downregulated in the cell lines and tissues of HCC. Downregulation of FBP1 in HCC tissues was correlated with a lower overall survival rate and had a relatively higher tendency of tumor recurrence (n = 224). Silencing FBP1 could significantly promote colony formation, proliferation and metastasis of HCC cells, while ectopic overexpression of FBP1 resulted in impaired abilities of colony formation, proliferation and metastasis in vitro and in vivo. Mechanistically, silencing FBP1 facilitated glycolysis in HCC cell lines, which may be responsible for aggressiveness of HCC cells. We further found that targeting the Warburg effect using the specific inhibitor FX11 could suppress the aggressiveness of HCC cells which was mediated by loss of FBP1. These findings indicate that FBP1 appears to be a tumor suppressor in HCC. Strategies to restore the levels and activities of FBP1 might be developed to treat patients with HCC.

Rubricella aquisinus gen. nov., sp. nov., a novel member of the family Rhodobacteraceae.

A Gram-stain negative, ovoid or short rod-shaped, aerobic and non-motile bacterial strain, designated J82T, was isolated from a seawater sample collected from the coast of Yellow Sea in Qingdao, China. The strain grew at salinities of 1.0-6.0% (w/v) NaCl (optimum, 2.5%). Growth occurred at pH 6.0-8.0 (optimum, pH 7.0) and 10-42 °C (optimum, 28-30 °C). The genomic DNA G + C content was determined to be 57.5 mol%. Q-10 was detected as the respiratory quinone. The major fatty acid (>10%) was Summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain J82T forms a distinct evolutionary lineage within the family Rhodobacteraceae. On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, the strain merits recognition as representative of a novel genus and species within the family Rhodobacteraceae for which the name Rubricella aquisinus gen. nov., sp. nov. is proposed. The type strain of Rubricella aquisinus is J82T (= DSM 103377T = CCTCC AB 2016170T).

LIFR functions as a metastasis suppressor in hepatocellular carcinoma by negatively regulating phosphoinositide 3-kinase/AKT pathway.

Hepatocellular carcinoma (HCC) is one of the leading causes for cancer related mortality worldwide. Poor prognosis of HCC patients is mainly due to frequent metastasis and recurrence. Deregulation of metastasis suppressors in malignant cells plays critical roles during cancer metastasis. Thus, novel metastasis suppressors are urgently needed to be uncovered to shed new light on molecular mechanisms driving HCC metastasis. In the present study, decreased expression of leukemia inhibitory factor receptor (LIFR) was demonstrated in HCC, and its expression levels were even lower in HCC with metastasis. Downregulated LIFR expression predicted poor prognosis in HCC patients. LIFR was an independent and significant risk factor for their recurrence and survival. Silencing LIFR resulted in forced metastasis of HCC cells, whereas ectopic overexpression of LIFR attenuated migration and invasion of HCC cells in vitro and in vivo. Moreover, LIFR knockdown could activate phosphoinositide 3-kinase/V-akt Murine Thymoma Viral Oncogene Homolog (PI3K/AKT) signaling through enhancing phosphorylation of Janus kinase 1 (JAK1), which successively promoted matrix metalloproteinase 13 (MMP13) expression and HCC metastasis. Combination of LIFR and p-AKT or MMP13 was a more powerful predictor of poor prognosis for HCC patients. Together, these findings conclude that LIFR functions as a novel metastasis suppressor in HCC and may serve as a prognostic biomarker for HCC patients.

PKM2 regulates neural invasion of and predicts poor prognosis for human hilar cholangiocarcinoma.

BACKGROUND: The therapeutic and prognostic value of the glycolytic enzymes hexokinase, phosphofructokinase, and pyruvate kinase (PK) has been implicated in a variety of cancers, while their roles in treatment of and prognosis for hilar cholangiocarcinoma (HC) remain unclear. In this study, we determined the expression of PKM2 in and its impact on biology and clinical outcome of human HC. METHODS: The regulation and function of PKM2 in HC pathogenesis was evaluated using human tissues, molecular and cell biology, and animal models, and its prognostic significance was determined according to its impact on patient survival. RESULTS: We found that expression of hexokinase 1 and the M2 splice isoform of PK (PKM2) was upregulated in HC tissues and that this expression correlated with tumor recurrence and outcome. PKM2 expression was increased in HC cases with chronic cholangitis as demonstrated by isobaric tags for relative and absolute quantification. High PKM2 expression was highly correlated with high syndecan 2 (SDC2) expression and neural invasion. PKM2 downregulation led to a decrease in SDC2 expression. Treatment with metformin markedly suppressed PKM2 and SDC2 expression at both the transcriptional and posttranscriptional levels and inhibited HC cell proliferation and tumor growth. CONCLUSIONS: PKM2 regulates neural invasion of HC cells at least in part via regulation of SDC2. Inhibition of PKM2 and SDC2 expression contributes to the therapeutic effect of metformin on HC. Therefore, PKM2 is an independent prognostic factor and potential therapeutic target for human HC.

GLYAT suppresses liver cancer and clear cell renal cell carcinoma progression by downregulating ROCK1 expression.

Background: The liver and kidney are important metabolic organs in the body and common sites of tumor occurrence. Glycine-N-acyltransferase (GLYAT) is primarily expressed in the liver and kidney and downregulated in several tumors. But its specific functions and molecular mechanisms in liver cancer and clear cell renal cell carcinoma (ccRCC) have not yet been fully elucidated. The aim of this study was to explore the role and clinical significance of GLYAT in liver cancer and ccRCC. Methods: This study used proteomics technology to identify differentially expressed proteins in liver cancer. Western blot and immunohistochemistry (IHC) were used to analyze the protein expression pattern of GLYAT. assays were performed in liver cancer and ccRCC cells. Xenograft models in nude mice were used to confirm the roles of GLYAT in liver cancer. Moreover, the downstream regulatory proteins of GLYAT were identified by proteomics. Results: GLYAT was lowly expressed in liver cancer and ccRCC. Immunofluorescence staining indicated that GLYAT was mainly expressed in the cytoplasm, particularly the mitochondria. Kaplan-Meier curves showed that the low protein expression of GLYAT was correlated with a poor prognosis in liver cancer and ccRCC patients. Moreover, GLYAT expression was associated with several clinical parameters in liver cancer. Cell experiments showed that the overexpression of GLYAT inhibited cell proliferation and migration abilities; however, interfering GLYAT protein expression rescued these abilities in GLYAT overexpression (GLYAT-OE) cells. In vivo assays confirmed the tumor-suppressor function of GLYAT in liver cancer. Moreover, our research showed that GLYAT downregulated Rho-associated coiled-coil-containing protein kinase 1 (ROCK1). Conclusions: Our study showed that GLYAT is lowly expressed in liver cancer and ccRCC, emphasizing its prognostic significance. It also showed that GLYAT inhibits the progression of liver cancer and ccRCC by downregulating ROCK1.

Clinical significance of ribosome production factor 2 homolog in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Dysregulation of ribosome biogenesis increases the risk of cancer. RPF2 (ribosome production factor 2 homolog), a member of the BRIX family, is involved in ribosome biogenesis. However, the biological functions of RPF2 in HCC remain unclear. This study aims to evaluate the function of RPF2 and its clinical significance in HCC. We collected 45 pairs of HCC/adjacent samples and 291 HCC samples. These samples were used to perform immunohistochemical analysis and western blot. Six cell lines were used to perform western blot, and two of cell lines, SMCC-7721 and SNU449, were subjected to CCK-8, wound healing and transwell assays. Immunofluorescence staining was executed in SMCC-7721 cells. The protein levels of RPF2 were higher in HCC tissues than in adjacent tissues. Immunofluorescence staining showed that the RPF2 protein was located in the nucleuses, especially the nucleolus. Furthermore, the immunohistochemical analysis showed that high expression levels of nuclear RPF2 correlated with poor prognosis, vascular invasion, liver cirrhosis and tumor size. Cell experiments showed that overexpression of RPF2 promoted cell proliferation, migration and invasion, while knockdown of RPF2 tended to show the opposite effect. This is the first report that RPF2 is involved in HCC progression. The levels of RPF2 were significantly high in HCC tumors and had a side effect on prognosis in HCC patients. RPF2 has the potential to be a useful marker for HCC.