Decreased expression of LASS2 is associated with worse prognosis in meningiomas

Biomarkers for prognosis of meningioma patients: A systematic review and meta-analysis

Meningioma is the most common primary brain tumor and many studies have evaluated numerous biomarkers for their prognostic value, often with inconsistent results. Currently, no reliable biomarkers are available to predict the survival, recurrence, and progression of meningioma patients in clinical practice. This study aims to evaluate the prognostic value of immunohistochemistry-based (IHC) biomarkers of meningioma patients. A systematic literature search was conducted up to November 2023 on PubMed, CENTRAL, CINAHL Plus, and Scopus databases. Two authors independently reviewed the identified relevant studies, extracted data, and assessed the risk of bias of the studies included. Meta-analyses were performed with the hazard ratio (HR) and 95% confidence interval (CI) of overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). The risk of bias in the included studies was evaluated using the Quality in Prognosis Studies (QUIPS) tool. A total of 100 studies with 16,745 patients were included in this review. As the promising markers to predict OS of meningioma patients, Ki-67/MIB-1 (HR = 1.03, 95%CI 1.02 to 1.05) was identified to associate with poor prognosis of the patients. Overexpression of cyclin A (HR = 4.91, 95%CI 1.38 to 17.44), topoisomerase II α (TOP2A) (HR = 4.90, 95%CI 2.96 to 8.12), p53 (HR = 2.40, 95%CI 1.73 to 3.34), vascular endothelial growth factor (VEGF) (HR = 1.61, 95%CI 1.36 to 1.90), and Ki-67 (HR = 1.33, 95%CI 1.21 to 1.46), were identified also as unfavorable prognostic biomarkers for poor RFS of meningioma patients. Conversely, positive progesterone receptor (PR) and p21 staining were associated with longer RFS and are considered biomarkers of favorable prognosis of meningioma patients (HR = 0.60, 95% CI 0.41 to 0.88 and HR = 1.89, 95%CI 1.11 to 3.20). Additionally, high expression of Ki-67 was identified as a prognosis biomarker for poor PFS of meningioma patients (HR = 1.02, 95%CI 1.00 to 1.04). Although only in single studies, KPNA2, CDK6, Cox-2, MCM7 and PCNA are proposed as additional markers with high expression that are related with poor prognosis of meningioma patients. In conclusion, the results of the meta-analysis demonstrated that PR, cyclin A, TOP2A, p21, p53, VEGF and Ki-67 are either positively or negatively associated with survival of meningioma patients and might be useful biomarkers to assess the prognosis.

Natural Products and Small Molecules Targeting Cellular Ceramide Metabolism to Enhance Apoptosis in Cancer Cells

Molecular targeting strategies have been used for years in order to control cancer progression and are often based on targeting various enzymes involved in metabolic pathways. Keeping this in mind, it is essential to determine the role of each enzyme in a particular metabolic pathway. In this review, we provide in-depth information on various enzymes such as ceramidase, sphingosine kinase, sphingomyelin synthase, dihydroceramide desaturase, and ceramide synthase which are associated with various types of cancers. We also discuss the physicochemical properties of well-studied inhibitors with natural product origins and their related structures in terms of these enzymes. Targeting ceramide metabolism exhibited promising mono- and combination therapies at preclinical stages in preventing cancer progression and cemented the significance of sphingolipid metabolism in cancer treatments. Targeting ceramide-metabolizing enzymes will help medicinal chemists design potent and selective small molecules for treating cancer progression at various levels.

Alternative splicing of ceramide synthase 2 alters levels of specific ceramides and modulates cancer cell proliferation and migration in Luminal B breast cancer subtype

Global dysregulation of RNA splicing and imbalanced sphingolipid metabolism has emerged as promoters of cancer cell transformation. Here, we present specific signature of alternative splicing (AS) events of sphingolipid genes for each breast cancer subtype from the TCGA-BRCA dataset. We show that ceramide synthase 2 (CERS2) undergoes a unique cassette exon event specifically in Luminal B subtype tumors. We validated this exon 8 skipping event in Luminal B cancer cells compared to normal epithelial cells, and in patient-derived tumor tissues compared to matched normal tissues. Differential AS-based survival analysis shows that this AS event of CERS2 is a poor prognostic factor for Luminal B patients. As Exon 8 corresponds to catalytic Lag1p domain, overexpression of AS transcript of CERS2 in Luminal B cancer cells leads to a reduction in the level of very-long-chain ceramides compared to overexpression of protein-coding (PC) transcript of CERS2. We further demonstrate that this AS event-mediated decrease of very-long-chain ceramides leads to enhanced cancer cell proliferation and migration. Therefore, our results show subtype-specific AS of sphingolipid genes as a regulatory mechanism that deregulates sphingolipids like ceramides in breast tumors, and can be explored further as a suitable therapeutic target.

The prognostic role of Ki-67/MIB-1 in meningioma: A systematic review with meta-analysis

BACKGROUND

Ki-67 is a typical immunohistochemical marker for cell proliferation. Higher expression of Ki-67 is correlated with poor clinical outcomes in several cancers. However, the prognostic value of Ki-67 on the prognosis of meningiomas is still controversial. The purpose of this meta-analysis was to evaluate the prognostic value of Ki-67 in meningiomas.

METHODS AND MATERIALS

We searched Medline and EMBASE from inception to December 31, 2018, to identify relevant articles. Using a fixed or random effects model, pooled hazard ratios (HRs) for overall survival (OS) and disease/progression/recurrence-free survival (D/P/RFS) were estimated.

RESULTS

A total of 43 studies, comprising 5012 patients, were included in this analysis. Higher Ki-67 expression levels were significantly associated with worse OS (HR = 1.565; 95% CI: 1.217-2.013) and D/P/RFS (HR = 2.644; 95% CI: 2.264-3.087) in meningiomas. Subgroup analysis revealed that all the included factors (ethnicity, tumor grade, HR sources, definition of cutoffs, cutoff values) for heterogeneity investigation can affect the pooled results. Among them, the definitions of cutoffs and cutoff values factor are the two main contributors toward heterogeneity. Multivariable meta-regression analysis also showed that methodologies used for cutoff value definition contributed to the high inner-study heterogeneity.

CONCLUSIONS

Higher Ki-67 expression levels negatively influenced survival in meningiomas. A higher cutoff value (>4%) is more appropriate for prognosis prediction. It is highly recommended that Ki-67 expression profile could be assessed in meningiomas treatment for predicting survival. And patients with elevated expression of Ki-67 need to have close follow-ups.

JAZF1 Suppresses Papillary Thyroid Carcinoma Cell Proliferation and Facilitates Apoptosis via Regulating TAK1/NF-κB Pathways

Purpose

Juxtaposed with another zinc finger gene 1 (JAZF1) is involved in gluconeogenesis, insulin sensitivity, cell differentiation, lipid metabolism and inflammation, but its role in carcinoma remains inexplicit.

Patients and methods

We explored the JAZF1 expression in human papillary thyroid cancer (PTC) tissues, adjacent normal thyroid tissues and nodular goitre tissues, as well as Ki67 expression in PTC tissues, using immunohistochemistry staining. Western blotting and RT-qPCR were performed to explore the JAZF1 expression levels in Nthy-ori 3–1, BCPAP and TPC-1 cells. BCPAP cells overexpressing JAZF1 were constructed using an Adv-JAZF1-GFP recombinant adenovirus vector. Next, the cell proliferation assay, colony formation assay, cell cycle analysis, apoptosis and immunofluorescence were performed. The mRNA expression level of nuclear factor-κB p65 (NF-κB p65) was examined using RT-qPCR. The expression of Bcl-2, Bax, transforming growth factor beta-activated kinase 1 (TAK1), NF-κB p65 and NF-κB p-p65 were examined using Western blotting.

Results

The expression of JAZF1 in human PTC tissues was downregulated compared with adjacent thyroid tissues or nodular goitre. Additionally, JAZF1 expression was associated with the location and lymph node metastasis of PTC. The expression level of JAZF1 had a negative correlation with Ki67 labelling index (LI). Compared to Nthy-ori 3–1 cells and TPC-1 cells, BCPAP cells expressed the lowest JAZF1. JAZF1 overexpressed significantly inhibited proliferation, caused G0/G1 cell cycle arrest and promoted apoptosis in BCPAP cells. Furthermore, JAZF1 overexpressed in BCPAP cells clearly upregulated the expression level of Bax protein, whereas decreased the expression of Bcl-2, TAK1, NF-κB but did not affect the mRNA or protein expression level of NF-κB p65.

Conclusion

JAZF1 inhibits proliferation and induces apoptosis in BCPAP cells by suppressing the activation of TAK1/NF-κB signalling pathways, suggesting that JAZF1 may serve as a reliable molecular marker in PTC.

High expression of LASS2 is associated with unfavorable prognosis in patients with ovarian cancer

Homo sapiens longevity assurance homolog 2 of yeast LAG1 (LASS2), is a gene isolated from a human liver complementary DNA library. In this study, we found that LASS2 protein level was positively related to International Federation of Gynecology and Obstetrics (FIGO) stage and LASS2-negative tumors showed significant association with longer disease-free survival (DFS) and overall survival (OS) in ovarian cancer patients. The heterogeneous expression of LASS2 had been exhibited in diverse ovarian cancer cells. A significantly lower messenger RNA (mRNA) and protein level of LASS2 was seen in 3AO cell compared with those in other types of ovarian cancer cells. Meanwhile, the mRNA and protein levels of LASS2 in ES-2 and NIH:OVCAR-3 cells were obviously higher. LASS2 overexpression in 3AO cell could promote migration, invasion, and metastasis abilities in vitro and in vivo, while LASS2 knockdown in ES-2 and NIH:OVCAR-3 cells had the opposite effects. The oncogenic capacity of LASS2 in ovarian cancer may be mediated by increased expression of YAP/TAZ. It is indicated that lowering the expression of LASS2 is likely to serve as an unprecedented approach for the treatment of ovarian cancer.

Overexpression of LASS2 inhibits proliferation and causes G0/G1 cell cycle arrest in papillary thyroid cancer

Background

The aim of this study was to investigate the role of LAG1 longevity-assurance homologue 2 (LASS2) in papillary thyroid cancer (PTC).

Methods

Immunohistochemistry staining was conducted to explore the expression levels of LASS2 in PTC tissues and adjacent normal thyroid tissues and nodular goiter tissues. Western blotting and RT-qPCR were performed to explore the expression levels of LASS2 in three PTC cell lines (TPC-1, K1, BCPAP). An Adv-LASS2-GFP recombinant adenovirus vector was constructed and transduced into BCPAP cells. Then CCK-8 assay, colony formation assay, cell cycle distribution, and apoptosis were performed. Western blotting was used to examine the expression of p21, cyclin D1, cyclin-dependent kinase 4, p53 and p-p53.

Results

LASS2 was downregulated in PTC tissues compared with adjacent thyroid tissues or nodular goiter tissues. In addition, the expression of LASS2 was found to be associated with TNM stage and lymph node metastasis. BCPAP cells expressed the lowest LASS2 compared to TPC-1 cells or K1 cells. Overexpression of LASS2 significantly inhibited proliferation, promoted apoptosis and caused G0/G1 cell cycle arrest in BCPAP cells. Furthermore, overexpression of LASS2 significantly increased the expression of p21, inhibited the expression of cyclin D1 and cyclin-dependent kinase 4, and increased the expression of p-p53, but did not effect the expression of p53 in BCPAP cells.

Conclusion

Our findings indicate that overexpression of LASS2 inhibits PTC cell proliferation, promotes apoptosis and causes G0/G1 cell cycle arrest via a p53-dependent pathway. Thus, LASS2 may serve as a novel biomarker in PTC.

Chemosensitivity of human colon cancer cells is influenced by a p53-dependent enhancement of ceramide synthase 5 and induction of autophagy

Resistance against chemotherapy is a life-threatening complication in colon cancer therapy. To increase response rate, new additional targets that contribute to chemoresistance are still needed to be explored. Ceramides, which belong to the group of sphingolipids, are well-known regulators of cell death and survival, respectively. Here, we show that in human wild-type (^wt) p53 HCT-116 colon cancer cells treatment with oxaliplatin or 5-fluorouracil (5-FU) leads to a strong increase in ceramide synthase 5 (CerS5) expression and C_16:0-ceramide levels, which was not shown in HCT-116 lacking p53 expression (HCT-116 p53^-/-). The increase in CerS5 expression occurs by stabilizing CerS5 mRNA at the 3'-UTR. By contrast, in the p53-deficient cells CerS2 expression and CerS2-related C_24:0- and C_24:1-ceramide levels were elevated which is possibly related to enhanced polyadenylation of the CerS2 transcript in these cells. Stable knockdown of CerS5 expression using CerS5-targeting shRNA led to an increased sensitivity of HCT-116 p53^wt cells, but not of p53^-/- cells, to oxaliplatin and 5-FU. Enhanced sensitivity was accompanied by an inhibition of autophagy and inhibition of mitochondrial respiration in these cells. However, knockdown of CerS2 had no significant effects on chemosensitivity of both cell lines. In conclusion, in p53^wt colon cancer cells chemosensitivity against oxaliplatin or 5-FU could be enhanced by downregulation of CerS5 expression leading to reduced autophagy and mitochondrial respiration.

Brain invasion in meningiomas-clinical considerations and impact of neuropathological evaluation: a systematic review

With the release of the 2016 edition of the World Health Organization (WHO) Classification of Central Nervous System Tumors, brain invasion in meningiomas has been added as a stand-alone criterion for atypia and can therefore impact grading and indirectly adjuvant therapy. Regarding this rising clinical importance, we have reviewed the current knowledge about brain invasion with emphasis on its implications on current and future clinical practice. We found various definitions of brain invasion and approaches for evaluation in surgically obtained specimens described over the past decades. This heterogeneity is reflected by weak correlation with prognosis and remains controversial. Similarly, associated clinical factors are largely unknown. Preoperative, imaging-guided detection of brain invasion is unspecific, and intraoperative assessment using standard and new high-magnification microscopic techniques remains imprecise. Despite the increasing knowledge about molecular alterations of the tumor/ brain surface, pharmacotherapeutic options targeting brain invasive meningiomas are lacking. Finally, we summarize the impact of brain invasion on histopathological grading in the WHO classifications of brain tumors since 1979.In conclusion, standardized neurosurgical sampling and neuropathological analyses could improve diagnostic reliability and reproducibility of future studies. Further research is needed to improve pre- and intraoperative visualization of brain invasion and to develop adjuvant, targeted therapies.

Hepatocyte-specific deletion of LASS2 protects against diet-induced hepatic steatosis and insulin resistance

Homo sapienslongevity assurance homolog 2 of yeast LAG1 (LASS2) is expressed mostly in human liver. Here, we explored roles of LASS2 in pathogenesis of hepatic steatosis. Hepatocyte-specific LASS2 knockout (LASS2^-/-) mice were generated using Cre-LoxP system. LASS2^-/- and wild-type (WT) mice were fed with chow or high-fat diet (HFD). We found LASS2^-/- mice were resistant to HFD-induced hepatic steatosis and insulin resistance. In HFD-fed mice, LASS2 deficiency significantly inhibited p38 MAPK and ERK1/ERK2 signaling in mouse liver. This effect was mediated by a significant increase of V-ATPase activity and a decrease of ROS level. We also observed that elevated expression of LASS2 in mouse hepatocyte cell line AML12 obviously decreased V-ATPase activity and increased ROS level by activation of p38 MAPK and ERK1/ERK2 signaling. Our findings indicate that LASS2 plays an important role in the pathogenesis of diet-induced hepatic steatosis and is a potential novel target for prevention and intervention of liver diseases.

Co-expression of LASS2 and TGF-β1 predicts poor prognosis in hepatocellular carcinoma

Longevity assurance homolog 2 of yeast LAG1 (LASS2) has been reported to act as an important tumor suppressor in the development of human cancers. However, little is known about the prognostic value of LASS2 in hepatocellular carcinoma (HCC) . In the present study, we analyzed correlation between LASS2 and TGF-β1 levels, and evaluated their prognostic values in HCC patients. We first analyzed the expression of LASS2 and TGF-β1 in two independent cohorts (test cohort: 184 HCC patients; validation cohort: 118 HCC patients) using immunohistochemistry (IHC). Kaplan-Meier survival and Cox regression analyses were executed to evaluate the prognosis of HCC. The results of IHC analysis revealed a positive correlation between the expression of LASS2 and TGF-β1. HCC Patients with low expression of LASS2 and TGF-β1 had shorter overall survival (OS) and time to recurrence (TTR) than patients with high expression of LASS2 and TGF-β1. Furthermore, combination of LASS2 and TGF-β1 was an independent and significant risk factor for OS and TTR. In conclusion, low expression of LASS2 and TGF-β1 contributes to the aggressiveness and poor prognosis of HCC, and may represent a novel prognostic biomarker for HCC patients.

The enigma of ceramide synthase regulation in mammalian cells

Ceramide synthases (CerS) are key enzymes in the lipid metabolism of eukaryotic cells. Their products, ceramides (Cer), are components of cellular membranes but also mediate signaling functions in physiological processes such as proliferation, skin barrier function and cerebellar development. In pathophysiological processes such as multiple sclerosis and tumor progression, ceramide levels are altered, which can be ascribed, partly, to dysregulation of CerS gene transcription. Most publications deal with the effects of altered ceramide levels on physiological and pathophysiological processes, but the regulation of the appropriate CerS is frequently not investigated. This is insufficient for the clarification of the role of ceramides, because most ceramide species are generated by at least two CerS. The mechanisms of CerS regulation are manifold and it seems that each CerS isoform is regulated individually. For this reason, we discuss the different CerS separately in this review. From transcriptional regulation to alteration of protein activity, the possibilities to influence CerS are diverse. Furthermore, CerS are influenced by a variety of molecules including hormones and lipids. Without claiming completeness, we provide a résumé of the regulatory mechanisms for each CerS in mammalian cells and how dysregulation of these mechanisms during physiological processes may lead to pathophysiological processes.