FABP5 promotes lymph node metastasis in cervical cancer by reprogramming fatty acid metabolism

The differential expression of AFF3 in cervical cancer and its correlation with clinicopathological features and prognosis

BACKGROUND

Cervical cancer (CC) is the second most common malignancy in women, and identifying biomarkers of CC is crucial for prognosis prediction. Here, we investigated the expression of AF4/FMR2 Family Member 3 (AFF3) in CC and its association with clinicopathological features and prognosis.

METHODS

Tumour and adjacent tissues, along with clinicopathological features and follow-up information, were collected from 78 patients. AFF3 expression was assessed using quantitative real-time polymerase chain reaction and Western blotting. The correlation between AFF3 expression and CC symptoms was using chi-square test. The 5-year overall survival (OS) was analysed using the Kaplan-Meier method. The Univariate analysis of prognostic risk factors was conducted using the COX proportional hazards model, followed by multivariate COX regression analysis including variables with p < 0.01.

RESULTS

AFF3 expression was downregulated in CC, and its levels were correlated with lymph node metastasis (LNM) and International Federation of Gynaecology and Obstetrics (FIGO) stage. Patients with low AFF3 expression had a lower 5-year OS rate (52.78%, 19/36). Postoperative survival was reduced in patients with histological grade 3 (G3), myometrial invasion (depth ≥ 1/2), lymphovascular space invasion, LNM, and advanced FIGO stage. Low expression of AFF3 (HR: 2.848, 95% CI: 1.144-7.090) and histological grade G3 (HR: 4.393, 95% CI: 1.663-11.607) were identified as independent prognostic risk factors in CC patients.

CONCLUSION

Low expression of AFF3 and histological G3 are independent predictors of poor prognosis in CC patients, suggesting that AFF3 could serve as a potential biomarker for prognostic assessment in CC.

Mitochondria targeted drug delivery system overcoming drug resistance in intrahepatic cholangiocarcinoma by reprogramming lipid metabolism

The challenge of drug resistance in intrahepatic cholangiocarcinoma (ICC) is intricately linked with lipid metabolism reprogramming. The hepatic lipase (HL) and the membrane receptor CD36 are overexpressed in BGJ398-resistant ICC cells, while they are essential for lipid uptake, further enhancing lipid utilization in ICC. Herein, a metal-organic framework-based drug delivery system (OB@D-pMOF/CaP-AC, DDS), has been developed. The specifically designed DDS exhibits a successive targeting property, enabling it to precisely target ICC cells and their mitochondria. By specifically targeting the mitochondria, DDS produces reactive oxygen species (ROS) through its sonodynamic therapy effect, achieving a more potent reduction in ATP levels compared to non-targeted approaches, through the impairment of mitochondrial function. Additionally, the DDS strategically minimizes lipid uptake through the incorporation of the anti-HL drug, Orlistat, and anti-CD36 monoclonal antibody, reducing lipid-derived energy production. This dual-action strategy on both mitochondria and lipids can hinder energy utilization to restore drug sensitivity to BGJ398 in ICC. Moreover, an orthotopic mice model of drug-resistant ICC was developed, which serves as an exacting platform for evaluating the multifunction of designed DDS. Upon in vivo experiments with this model, the DDS demonstrated exceptional capabilities in suppressing tumor growth, reprogramming lipid metabolism and improving immune response, thereby overcoming drug resistance. These findings underscore the mitochondria-targeted DDS as a promising and innovative solution in ICC drug resistance.

Association between body mass index and lymph node metastasis among women with cervical cancer: a systematic review and network meta-analysis

PURPOSE

Lymph node status is a determinant of survival in patients with early-stage cervical cancer. However, the relationship between obesity and lymph node status remains unclear. Therefore, this systematic review aims to evaluate the correlation between body mass index (BMI) and lymph node metastasis in cervical cancer.

METHODS

Cohort studies through six databases were reviewed until December 2021. Odds ratios (ORs) for lymphatic metastasis were estimated using random-effects models and network meta-analysis. BMI groups for lymph node metastasis were ranked. Heterogeneities were assessed using I2. Subgroup analyses were performed to determine possible sources of heterogeneity.

RESULTS

No significant difference was found between obese (BMI ≥ 25) and non-obese patients (BMI < 25) (OR = 1.01; 95% CI 0.69-1.47; P = 0.97). In subgroup analyses, obesity was associated with higher risk among the Americans and advanced-stage patients. The grouping analysis based on BMI and the rankogram values revealed that the '35 ≤ BMI' group had the highest risk of lymph node metastasis.

CONCLUSION

Although there were no significant differences in lymph node metastasis between obese and non-obese cervical cancer patients in overall analysis, patients with BMI ≥ 35 were at significantly higher risk of lymph node metastasis.

Identification of a metabolism-linked genomic signature for prognosis and immunotherapeutic efficiency in metastatic skin cutaneous melanoma

Metastatic skin cutaneous melanoma (MSCM) is the most rapidly progressing/invasive skin-based malignancy, with median survival rates of about 12 months. It appears that metabolic disorders accelerate disease progression. However, correlations between metabolism-linked genes (MRGs) and prognosis in MSCM are unclear, and potential mechanisms explaining the correlation are unknown. The Cancer Genome Atlas (TCGA) was utilized as a training set to develop a genomic signature based on the differentially expressed MRGs (DE-MRGs) between primary skin cutaneous melanoma (PSCM) and MSCM. The Gene Expression Omnibus (GEO) was utilized as a validation set to verify the effectiveness of genomic signature. In addition, a nomogram was established to predict overall survival based on genomic signature and other clinic-based characteristics. Moreover, this study investigated the correlations between genomic signature and tumor micro-environment (TME). This study established a genomic signature consisting of 3 genes (CD38, DHRS3, and TYRP1) and classified MSCM patients into low and high-risk cohorts based on the median risk scores of MSCM cases. It was discovered that cases in the high-risk cohort had significantly lower survival than cases in the low-risk cohort across all sets. Furthermore, a nomogram containing this genomic signature and clinic-based parameters was developed and demonstrated high efficiency in predicting MSCM case survival times. Interestingly, Gene Set Variation Analysis results indicated that the genomic signature was involved in immune-related physiological processes. In addition, this study discovered that risk scoring was negatively correlated with immune-based cellular infiltrations in the TME and critical immune-based checkpoint expression profiles, indicating that favorable prognosis may be influenced in part by immunologically protective micro-environments. A novel 3-genomic signature was found to be reliable for predicting MSCM outcomes and may facilitate personalized immunotherapy.

Fatty Acid Oxidation Supports Lymph Node Metastasis of Cervical Cancer via Acetyl-CoA-Mediated Stemness

Accumulating evidence indicates that metabolic reprogramming of cancer cells supports the energy and metabolic demands during tumor metastasis. However, the metabolic alterations underlying lymph node metastasis (LNM) of cervical cancer (CCa) have not been well recognized. In the present study, it is found that lymphatic metastatic CCa cells have reduced dependency on glucose and glycolysis but increased fatty acid oxidation (FAO). Inhibition of carnitine palmitoyl transferase 1A (CPT1A) significantly compromises palmitate-induced cell stemness. Mechanistically, FAO-derived acetyl-CoA enhances H3K27 acetylation (H3K27Ac) modification level in the promoter of stemness genes, increasing stemness and nodal metastasis in the lipid-rich nodal environment. Genetic and pharmacological loss of CPT1A function markedly suppresses the metastatic colonization of CCa cells in tumor-draining lymph nodes. Together, these findings propose an effective method of cancer therapy by targeting FAO in patients with CCa and lymph node metastasis.

Resveratrol, a novel inhibitor of fatty acid binding protein 5, inhibits cervical cancer metastasis by suppressing fatty acid transport into nucleus and downstream pathways

BACKGROUND AND PURPOSE

Because of cervical cancer (CC) metastasis, the prognosis of diagnosed patients is poor. However, the molecular mechanisms and therapeutic approach for metastatic CC remain elusive.

EXPERIMENTAL APPROACH

In this study, we first evaluated the effect of resveratrol (RSV) on CC cell migration and metastasis. Via an activity-based protein profiling (ABPP) approach, a photoaffinity probe of RSV (RSV-P) was synthesized, and the protein targets of RSV in HeLa cells were identified. Based on target information and subsequent in vivo and in vitro validation experiments, we finally elucidated the mechanism of RSV corresponding to its antimetastatic activity.

KEY RESULTS

The results showed that RSV concentration-dependently suppressed CC cell migration and metastasis. A list of proteins was identified as the targets of RSV, through the ABPP approach with RSV-P, among which fatty acid binding protein 5 (FABP5) attracted our attention based on The Cancer Genome Atlas (TCGA) database analysis. Subsequent knockout and overexpression experiments confirmed that RSV directly interacted with FABP5 to inhibit fatty acid transport into the nucleus, thereby suppressing downstream matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) expression, thus inhibiting CC metastasis.

CONCLUSIONS AND IMPLICATIONS

Our study confirmed the key role of FABP5 in CC metastasis and provided important target information for the design of therapeutic lead compounds for metastatic CC.

Modulation of Epithelial-Mesenchymal Transition Is a Possible Underlying Mechanism for Inducing Chemoresistance in MIA PaCa-2 Cells against Gemcitabine and Paclitaxel

To elucidate the currently unknown molecular mechanisms responsible for the similarity and difference during the acquirement of resistance against gemcitabine (GEM) and paclitaxel (PTX) in patients with pancreatic carcinoma, we examined two-dimensional (2D) and three-dimensional (3D) cultures of parent MIA PaCa-2 cells (MIA PaCa-2-PA) and their GEM resistance cell line (MIA PaCa-2-GR) and PTX resistance (MIA PaCa-2-PR). Using these cells, we examined 3D spheroid configurations and cellular metabolism, including mitochondrial and glycolytic functions, with a Seahorse bio-analyzer and RNA sequencing analysis. Compared to the MIA PaCa-2-PA, (1) the formation of the 3D spheroids of MIA PaCa-2-GR or -PR was much slower, and (2) their mitochondrial and glycolytic functions were greatly modulated in MIA PaCa-2-GR or -PR, and such metabolic changes were also different between their 2D and 3D culture conditions. RNA sequencing and bioinformatic analyses of the differentially expressed genes (DEGs) using an ingenuity pathway analysis (IPA) suggested that various modulatory factors related to epithelial -mesenchymal transition (EMT) including STAT3, GLI1, ZNF367, NKX3-2, ZIC2, IFIT2, HEY1 and FBLX, may be the possible upstream regulators and/or causal network master regulators responsible for the acquirement of drug resistance in MIA PaCa-2-GR and -PR. In addition, among the prominently altered DEGs (Log2 fold changes more than 6 or less than -6), FABP5, IQSEC3, and GASK1B were identified as unique genes associated with their antisense RNA or pseudogenes, and among these, FABP5 and GASK1B are known to function as modulators of cancerous EMT. Therefore, the observations reported herein suggest that modulations of cancerous EMT may be key molecular mechanisms that are responsible for inducing chemoresistance against GEM or PTX in MIA PaCa-2 cells.

TM7SF2-induced lipid reprogramming promotes cell proliferation and migration via CPT1A/Wnt/β-Catenin axis in cervical cancer cells

Cervical cancer poses a serious threat to women's health globally. Our previous studies found that upregulation of TM7SF2, which works as an enzyme involved in the process of cholesterol biosynthesis expression, was highly correlated with cervical cancer. However, the mechanistic basis of TM7SF2 promoting cervical cancer progression via lipid metabolism remains poorly understood. Therefore, quantification of fatty acids and lipid droplets were performed in vitro and in vivo. The protein-protein interaction was verified by Co-IP technique. The mechanism and underlying signaling pathway of TM7SF2 via CPT1A associated lipid metabolism in cervical cancer development were explored using Western blotting, IHC, colony formation, transwell assay, and wound healing assay. This study reported that overexpression of TM7SF2 increased fatty acids content and lipid droplets both in vivo and in vitro experiments. While knockout of TM7SF2 obviously attenuated this process. Moreover, TM7SF2 directly bonded with CPT1A, a key enzyme in fatty acid oxidation, and regulated CPT1A protein expression in cervical cancer cells. Notably, the proliferation and metastasis of cervical cancer cells were elevated when their CPT1A expression was upregulated. Then, rescue assay identified that CPT1A overexpressed could enhance the cell viability and migration in TM7SF2-knockout cells. Furthermore, depletion of TM7SF2 significantly inhibited WNT and β-catenin proteins expression, which was enhanced by CPT1A-overexpressed. The proliferation and migration of cervical cancer cells were reversed in CPT1A-overexpressed cells with the treatment of MSAB, an inhibitor of Wnt/β-Catenin pathway. This study put forward an idea that TM7SF2-induced lipid reprogramming promotes proliferation and migration via CPT1A/Wnt/β-Catenin axis in cervical cancer, underlying the progression of cervical cancer.

Genetic analysis of cervical cancer with lymph node metastasis

OBJECTIVE

To find out the differences in gene characteristics between cervical cancer patients with and without lymph node metastasis, and to provide reference for therapy.

METHODS

From January 2018 to June 2022, recurrent cervical cancer patients 39 cases with lymph node metastasis and 73 cases without lymph node metastasis underwent testing of 1,021 cancer-related genes by next-generation sequencing. Maftools software was used to analyze somatic single nucleotide/insertion-deletion variation mutation, co-occurring mutation, cosmic mutation characteristics, oncogenic signaling pathways.

RESULTS

EP300 and FBXW7 were significantly enriched in lymph node-positive patients. Lymph node-positive patients with EP300 or FBXW7 mutations had lower overall survival (OS) after recurrence. Both lymph node-positive and -negative patients had plenty of co-occurring mutations but few mutually exclusive mutations. Lymph node-positive co-occurring mutation number ≥6 had lower OS, while lymph node-negative co-occurring mutation number ≥3 had lower OS after recurrence. The etiology of SBS3 was defects in DNA double strand break repair by homologous recombination, which exclusively exist in lymph node-positive patients. There was no difference in median tumor mutation burden (TMB) between positive and negative lymph nodes, but TMB was significantly associated with PIK3CA mutation.

CONCLUSION

The somatic SNV/Indels of EP300 and FBXW7, SBS3 homologous recombination-mediated DNA repair defect were enriched in lymph node-positive patients. For lymph node-positive patients, EP300 or FBXW7 mutations predicted poor prognosis. No matter lymph node-positive or negative, more co-occurring mutation number predicted poor prognosis. PIK3CA mutation may account for the higher TMB and help identify patients who benefit from immunotherapy.

Genetic or pharmacologic blockade of mPGES-2 attenuates renal lipotoxicity and diabetic kidney disease by targeting Rev-Erbα/FABP5 signaling

Diabetic kidney disease (DKD) is one of the most common complications of diabetes, and no specific drugs are clinically available. We have previously demonstrated that inhibiting microsomal prostaglandin E synthase-2 (mPGES-2) alleviated type 2 diabetes by enhancing β cell function and promoting insulin production. However, the involvement of mPGES-2 in DKD remains unclear. Here, we aimed to analyze the association of enhanced mPGES-2 expression with impaired metabolic homeostasis of renal lipids and subsequent renal damage. Notably, global knockout or pharmacological blockage of mPGES-2 attenuated diabetic podocyte injury and tubulointerstitial fibrosis, thereby ameliorating lipid accumulation and lipotoxicity. These findings were further confirmed in podocyte- or tubule-specific mPGES-2-deficient mice. Mechanistically, mPGES-2 and Rev-Erbα competed for heme binding to regulate fatty acid binding protein 5 expression and lipid metabolism in the diabetic kidney. Our findings suggest a potential strategy for treating DKD via mPGES-2 inhibition.

The role of NF-κB in carcinogenesis of cervical cancer: opportunities and challenges

The nuclear factor-κB (NF-κB) family, consisting of several transcription factors, has been implicated in the regulation of cell proliferation and invasion, as well as inflammatory reactions and tumor development. Cervical cancer (CC) results from long-term interactions of multiple factors, among which persistent high-risk human papillomavirus (hrHPV) infection is necessary. During different stages from early to late after HPV infection, the activity of NF-κB varies and plays various roles in carcinogenesis and progress of CC. As the center of the cell signaling transduction network, NF-κB can be activated through classical and non-classical pathways, and regulate the expression of downstream target genes involved in regulating the tumor microenvironment and acquiring hallmark traits of CC cells. Targeting NF-κB may help treat CC and overcome the resistance to radiation and chemotherapy. Even though NF-κB inhibitors have not been applied in clinical treatment as yet, due to limitations such as dose-restrictive toxicity and poor tumor-specificity, it is still considered to have significant therapeutic potential and application prospects. In this review, we focus on the role of NF-κB in the process of CC occurrence and hallmark capabilities acquisition. Finally, we summarize relevant NF-κB-targeted treatments, providing ideas for the prevention and treatment of CC.

Lipid droplets' functional protein caveolin-2 is associated with lipid metabolism-related molecule FABP5 and EMT marker E-cadherin in oral epithelial dysplasia

AIMS

To explore the accumulation of lipid droplets (LDs) and its relationship with lipid metabolism, and epithelial-mesenchymal transition (EMT) in the carcinogenesis processes in the oral cavity.

METHODS

LDs were stained by oil red O. Forty-eight oral squamous cell carcinomas (OSCC), 78 oral potentially malignant disorders (OPMDs) and 25 normal tissue sections were included to explore the LDs surface protein caveolin-2 and perilipin-3, lipid metabolism-related molecule FABP5 and EMT biomarker E-cadherin expression by immunohistochemical staining.

RESULTS

The accumulation of LDs was observed in OPMDs and OSCCs compared with normal tissues (p<0.05). In general, an increasing trend of caveolin-2, perilipin-3 and FABP5 expression was detected from the normal to OPMDs to OSCC groups (p<0.05). Additionally, caveolin-2, perilipin-3 and FABP5 expression were positively correlated with epithelial dysplasia in OPMDs, whereas E-cadherin positivity was negatively correlated with histopathological grade in both OPMDs and OSCC, respectively. A negative correlation of caveolin-2 (p<0.01, r =-0.1739), and FABP5 (p<0.01, r =-0.1880) with E-cadherin expression was detected. The caveolin-2 (p<0.0001, r=0.2641) and perilipin-3 (p<0.05, r=0.1408) staining was positively correlated with FABP5. Increased caveolin-2 expression was related to local recurrence and worse disease-free survival (p<0.05).

CONCLUSION

In the oral epithelial carcinogenesis process, LDs begin to accumulate early in the precancerous stage. LDs may be the regulator of FABP5-associated lipid metabolism and may closely related to the process of EMT; caveolin-2 could be the main functional protein.

ACOT7 promotes retinoblastoma resistance to vincristine by regulating fatty acid metabolism reprogramming

The rate of vincristine (VCR) resistance in the treatment of retinoblastoma (RB) is relatively high, and the exact role and mechanism of autophagy and fatty acid (FA) metabolism in RB are still unknown. The aim of this study was to elucidate the molecular mechanism by which acyl-CoA thioesterase 7 (ACOT7) regulates FA metabolism and autophagy, which may lead to potential therapeutic strategies for RB. In the present study, the relationship between FA metabolism and cellular drug sensitivity was evaluated through ACOT7 overexpression or inhibition tests in RB-resistant cells. The lipase inhibitor orlistat and the autophagy inhibitor CQ were used to determine the effects of ACOT7 on FA metabolism, autophagy, and cellular drug sensitivity, as well as the therapeutic value of ACOT7 targeting. The results showed that ACOT7 was upregulated in VCR-resistant RB cells, significantly enhancing cell resistance and indicating that ACOT7 may serve as a biomarker for VCR resistance in RB cells. Knockdown of ACOT7 inhibited FA metabolism and reduced cell viability in VCR-resistant RB cells. The effect of ACOT7 overexpression was opposite to that of ACOT7 knockdown, and ACOT7 overexpression promoted autophagy in VCR-resistant RB cells. After treatment with orlistat or CQ, FA metabolism in VCR-resistant RB cells decreased, cell viability and autophagy were inhibited, EMT was inhibited, and the sensitivity of RB cells to VCR was increased. In conclusion, ACOT7 knockdown can mediate FA metabolism to inhibit autophagy and the migration of RB cells, thereby improving the sensitivity of RB cells to VCR.

DHCR7 promotes lymph node metastasis in cervical cancer through cholesterol reprogramming-mediated activation of the KANK4/PI3K/AKT axis and VEGF-C secretion

Cervical cancer (CC) patients with lymph node metastasis (LNM) have a poor prognosis. However, the molecular mechanism of LNM in CC is unclear, and there is no effective clinical treatment. Here, we found that 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the last step of cholesterol synthesis, was upregulated in CC and closely related to LNM. Gain-of-function and loss-of-function experiments proved that DHCR7 promoted the invasion ability of CC cells and lymphangiogenesis in vitro and induced LNM in vivo. The LNM-promoting effect of DHCR7 was partly mediated by upregulating KN motif and ankyrin repeat domains 4 (KANK4) expression and subsequently activating the PI3K/AKT signaling pathway. Alternatively, DHCR7 promoted the secretion of vascular endothelial growth factor-C (VEGF-C), and thereby lymphangiogenesis. Interestingly, cholesterol reprogramming was needed for the DHCR7-mediated promotion of activation of the KANK4/PI3K/AKT axis, VEGF-C secretion, and subsequent LNM. Importantly, treatment with the DHCR7 inhibitors AY9944 and tamoxifen (TAM) significantly inhibited LNM of CC, suggesting the clinical application potential of DHCR7 inhibitors in CC. Collectively, our results uncover a novel molecular mechanism of LNM in CC and identify DHCR7 as a new potential therapeutic target.

PBX1 as a novel master regulator in cancer: Its regulation, molecular biology, and therapeutic applications

PBX1 is a critical transcription factor at the top of various cell fate-determining pathways. In cancer, PBX1 stands at the crossroads of multiple oncogenic signaling pathways and mediates responses by recruiting a broad repertoire of downstream targets. Research thus far has corroborated the involvement of PBX1 in cancer proliferation, resisting apoptosis, tumor-associated neoangiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, immune evasion, genome instability, and dysregulating cellular metabolism. Recently, our understanding of the functional regulation of the PBX1 protein has advanced, as increasing evidence has depicted a regulatory network consisting of transcriptional, post-transcriptional, and post-translational levels of control mechanisms. Furthermore, accumulating studies have supported the clinical utilization of PBX1 as a prognostic or therapeutic target in cancer. Preliminary results showed that PBX1 entails vast potential as a targetable master regulator in the treatment of cancer, particularly in those with high-risk features and resistance to other therapeutic strategies. In this review, we will explore the regulation, protein-protein interactions, molecular pathways, clinical application, and future challenges of PBX1.

Plasma free fatty acid levels in cervical cancer: concurrent chemoradiotherapy improves abnormal profile

Background: Epidemiology has demonstrated that plasma free fatty acids (FFAs) can prevent the development of cancer. Our study sought to evaluate the relationship between plasma (FFA) levels and cervical cancer. Methods: In recent years, metabolomics-based approaches have been recognized as an emerging tool, so we examined the plasma FFA profiles of 114 patients with cervical cancer and 151 healthy people using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Results: The data results were analyzed by multifactorial binary logistic regression analysis, and it was found that palmitic acid, docosahexaenoic acid (DHA), and total ω-3 fatty acids were negatively correlated with the risk of cervical cancer; whereas tetracosanoic acid was positively correlated with the risk of cervical cancer (OR, 1.026; 95% CI, 1.013-1.040; p < 0.001). Dynamic follow-up of 40 cervical cancer patients who successfully completed CCRT revealed that most fatty acid levels tended to increase after the end of treatment, except for palmitic and stearic acid levels, which were lower than before treatment. Conclusion: Plasma FFA profiles were altered in cervical cancer patients, which may be related to abnormal fatty acid metabolism in cervical cancer. The described changes in fatty acid profiles during CCRT may be related to the good functioning of CCRT. Further studies on plasma FFA composition and its changes due to CCRT in patients with cervical cancer are warranted.

High levels of fatty acid-binding protein 5 excessively enhances fatty acid synthesis and proliferation of granulosa cells in polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most complex endocrine disorders in women of reproductive age. Abnormal proliferation of granulosa cells (GCs) is an important cause of PCOS. This study aimed to explore the role of fatty acid-binding protein 5 (FABP5) in granulosa cell (GC) proliferation in polycystic ovary syndrome (PCOS) patients.

METHODS

The FABP5 gene, which is related to lipid metabolism, was identified through data analysis of the gene expression profiles of GSE138518 from the Gene Expression Omnibus (GEO) database. The expression levels of FABP5 were measured by quantitative real-time PCR (qRT‒PCR) and western blotting. Cell proliferation was evaluated with a cell counting kit-8 (CCK-8) assay. Western blotting was used to assess the expression of the proliferation marker PCNA, and immunofluorescence microscopy was used to detect Ki67 expression. Moreover, lipid droplet formation was detected with Nile red staining, and qRT‒PCR was used to analyze fatty acid storage-related gene expression.

RESULTS

We found that FABP5 was upregulated in ovarian GCs obtained from PCOS patients and PCOS mice. FABP5 knockdown suppressed lipid droplet formation and proliferation in a human granulosa-like tumor cell line (KGN), whereas FABP5 overexpression significantly enhanced lipid droplet formation and KGN cell proliferation. Moreover, we determined that FABP5 knockdown inhibited PI3K-AKT signaling by suppressing AKT phosphorylation and that FABP5 overexpression activated PI3K-AKT signaling by facilitating AKT phosphorylation. Finally, we used the PI3K-AKT signaling pathway inhibitor LY294002 and found that the facilitation of KGN cell proliferation and lipid droplet formation induced by FABP5 overexpression was inhibited. In contrast, the PI3K-AKT signaling pathway agonist SC79 significantly rescued the suppression of KGN cell proliferation and lipid droplet formation caused by FABP5 knockdown.

CONCLUSIONS

FABP5 promotes active fatty acid synthesis and excessive proliferation of GCs by activating PI3K-AKT signaling, suggesting that abnormally high expression of FABP5 in GCs may be a novel biomarker or a research target for PCOS treatment.

IGF2BP3 enhances lipid metabolism in cervical cancer by upregulating the expression of SCD

Cervical cancer (CC) is the most common gynecologic malignancy, which seriously threatens the health of women. Lipid metabolism is necessary for tumor proliferation and metastasis. However, the molecular mechanism of the relationship between CC and lipid metabolism remains poorly defined. We revealed the expression of IGF2BP3 in CC exceeded adjacent tissues, and was positively associated with tumor stage using human CC tissue microarrays. The Cell Counting Kit-8, colony formation assay, 5-ethynyl-2'-deoxyuridine assay, transwell assays, wound-healing assays, and flow cytometry assessed the role of IGF2BP3 in proliferation and metastasis of CC cells. Besides, exploring the molecular mechanism participating in IGF2BP3-driven lipid metabolism used RNA-seq, which determined SCD as the target of IGF2BP3. Further, lipid droplets, cellular triglyceride (TG) contents, and fatty acids were accessed to discover that IGF2BP3 can enhance lipid metabolism in CC. Moreover, RIP assay and methylated RNA immunoprecipitation experiments seeked the aimed-gene-binding specificity. Lastly, the IGF2BP3 knockdown restrained CC growth and lipid metabolism, after which SCD overexpression rescued the influence in vitro and in vivo using nude mouse tumor-bearing model. Mechanistically, IGF2BP3 regulated SCD mRNA m6A modifications via IGF2BP3-METTL14 complex, thereby enhanced CC proliferation, metastasis, and lipid metabolism. Our study highlights IGF2BP3 plays a crucial role in CC progression and represents a therapeutic latent strategy. It is a potential tactic that blocks the metabolic pathway relevant to IGF2BP3 with the purpose of treating CC.

CircMAST1 inhibits cervical cancer progression by hindering the N4-acetylcytidine modification of YAP mRNA

BACKGROUND

Cervical cancer (CCa) is the fourth most common cancer among females, with high incidence and mortality rates. Circular RNAs (circRNAs) are key regulators of various biological processes in cancer. However, the biological role of circRNAs in cervical cancer (CCa) remains largely unknown. This study aimed to elucidate the role of circMAST1 in CCa.

METHODS

CircRNAs related to CCa progression were identified via a circRNA microarray. The relationship between circMAST1 levels and clinicopathological features of CCa was evaluated using the clinical specimens and data of 131 patients with CCa. In vivo and in vitro experiments, including xenograft animal models, cell proliferation assay, transwell assay, RNA pull-down assay, whole-transcriptome sequencing, RIP assay, and RNA-FISH, were performed to investigate the effects of circMAST1 on the malignant behavior of CCa.

RESULTS

CircMAST1 was significantly downregulated in CCa tissues, and low expression of CircMAST1 was correlated with a poor prognosis. Moreover, our results demonstrated that circMAST1 inhibited tumor growth and lymph node metastasis of CCa. Mechanistically, circMAST1 competitively sequestered N-acetyltransferase 10 (NAT10) and hindered Yes-associated protein (YAP) mRNA ac4C modification to promote its degradation and inhibit tumor progression in CCa.

CONCLUSIONS

CircMAST1 plays a major suppressive role in the tumor growth and metastasis of CCa. In particular, circMAST1 can serve as a potential biomarker and novel target for CCa.

FABP6 serves as a new therapeutic target in esophageal tumor

BACKGROUND

Esophageal cancer is one of the most common malignant tumors with high incidence and mortality rates. Despite the continuous development of treatment options, the prognosis for esophageal cancer patients remains poor. Therefore, there is an urgent need for new diagnostic and therapeutic targets in clinical practice to improve the survival of patients with esophageal cancer.

METHODS

In this study, we conducted a comprehensive scRNA-seq analysis of the tumor microenvironment in primary esophageal tumors to elucidate cell composition and heterogeneity. Using Seurat, we identified eight clusters, encompassing non-immune cells (fibroblasts, myofibroblasts, endothelial cells, and epithelial cells) and immunocytes (myeloid-derived cells, T cells, B cells, and plasma cells). Compared to normal tissues, tumors exhibited an increased proportion of epithelial cells and alterations in immune cell infiltration. Analysis of epithelial cells revealed a cluster (cluster 0) with a high differentiation score and early distribution, suggesting its importance as a precursor cell.

RESULTS

Cluster 0 was characterized by high expression of FABP6, indicating a potential role in fatty acid metabolism and tumor growth. T cell analysis revealed shifts in the balance between Treg and CD8+ effector T cells in tumor tissues. Cellular communication analysis identified increased interactions between FABP6+ tumor cells and T cells, with the involvement of the MIF-related pathway and the CD74-CD44 interaction. This study provides insights into the cellular landscape and immune interactions within esophageal tumors, contributing to a better understanding of tumor heterogeneity and potential therapeutic targets.

Lymphatic vessel: origin, heterogeneity, biological functions, and therapeutic targets

Lymphatic vessels, comprising the secondary circulatory system in human body, play a multifaceted role in maintaining homeostasis among various tissues and organs. They are tasked with a serious of responsibilities, including the regulation of lymph absorption and transport, the orchestration of immune surveillance and responses. Lymphatic vessel development undergoes a series of sophisticated regulatory signaling pathways governing heterogeneous-origin cell populations stepwise to assemble into the highly specialized lymphatic vessel networks. Lymphangiogenesis, as defined by new lymphatic vessels sprouting from preexisting lymphatic vessels/embryonic veins, is the main developmental mechanism underlying the formation and expansion of lymphatic vessel networks in an embryo. However, abnormal lymphangiogenesis could be observed in many pathological conditions and has a close relationship with the development and progression of various diseases. Mechanistic studies have revealed a set of lymphangiogenic factors and cascades that may serve as the potential targets for regulating abnormal lymphangiogenesis, to further modulate the progression of diseases. Actually, an increasing number of clinical trials have demonstrated the promising interventions and showed the feasibility of currently available treatments for future clinical translation. Targeting lymphangiogenic promoters or inhibitors not only directly regulates abnormal lymphangiogenesis, but improves the efficacy of diverse treatments. In conclusion, we present a comprehensive overview of lymphatic vessel development and physiological functions, and describe the critical involvement of abnormal lymphangiogenesis in multiple diseases. Moreover, we summarize the targeting therapeutic values of abnormal lymphangiogenesis, providing novel perspectives for treatment strategy of multiple human diseases.

An m1A/m6A/m5C-associated long non-coding RNA signature: Prognostic and immunotherapeutic insights into cervical cancer

BACKGROUND

Cervical cancer (CC) remains a significant clinical challenge, even though its fatality rate has been declining in recent years. Particularly in developing countries, the prognosis for CC patients continues to be suboptimal despite numerous therapeutic advances.

METHODS

Using The Cancer Genome Atlas database, we extracted CC-related data. From this, 52 methylation-related genes (MRGs) were identified, leading to the selection of a 10 long non-coding RNA (lncRNA) signature co-expressed with these MRGs. R programming was employed to filter out the methylation-associated lncRNAs. Through univariate, least absolute shrinkage and selection operator (i.e. LASSO) and multivariate Cox regression analysis, an MRG-associated lncRNA model was constructed. The established risk model was further assessed via the Kaplan-Meier method, principal component analysis, functional enrichment annotation and a nomogram. Furthermore, we explored the potential of this model with respect to guiding immune therapeutic interventions and predicting drug sensitivities.

RESULTS

The derived 10-lncRNA signature, linked with MRGs, emerged as an independent prognostic factor. Segmenting patients based on their immunotherapy responses allowed for enhanced differentiation between patient subsets. Lastly, we highlighted potential compounds for distinguishing CC subtypes.

CONCLUSIONS

The risk model, associated with MRG-linked lncRNA, holds promise in forecasting clinical outcomes and gauging the efficacy of immunotherapies for CC patients.

IRF2BP2 drives lymphatic metastasis in OSCC cells by elevating mitochondrial fission-dependent fatty acid oxidation

Lymph node metastasis (LNM) is a major determinant for the poor outcome of oral squamous cell carcinoma (OSCC). Interferon regulatory factor 2 binding protein 2 (IRF2BP2) has been reported to modulate the development and progression of several types of cancers, while its role in OSCC with LNM has not been reported yet. The expression of IRF2BP2 and its association with LNM were evaluated by immunohistochemistry and qualitative reverse transcription polymerase chain reaction in clinically collected OSCC tissues. Then, loss-of-function and rescue assays were conducted to identify the role of IRF2BP2-mediated fatty acid oxidation (FAO) in the invasion, lymphoinvasion, and epithelial-mesenchymal transition (EMT) in OSCC cells. Importantly, confocal microscope, transmission electron microscope, immunofluorescence, and Western blot were applied to identify the involvement of mitochondrial fission in IRF2BP2-regulated FAO. Lastly, the in vivo models were established to evaluate the role of IRF2BP2 in OSCC. IRF2BP2 overexpression has been associated with LNM in OSCC, whose knockdown inhibited invasion, lymphoinvasion, and EMT of OSCC cells, as well as retarded FAO rate with CPT1A downregulation. And CPT1A overexpression rescued invasion, lymphoinvasion, and induced EMT in IRF2BP2-silenced OSCC cells. Mechanically, IRF2BP2 accelerated mitochondrial fission by contributing to Drp1 S616 phosphorylation and mitochondrial localization, resulting in the upregulation of CPT1A. In addition, IRF2BP2 knockdown significantly inhibited tumor growth and LNM in vivo. The highly expressed IRF2BP2 may induce the phosphorylation and mitochondrial translocation of Drp1 to activate mitochondrial fission, which upregulated CPT1A expression and FAO rate, resulting in LNM in OSCC. This highlighted a potential therapeutic vulnerability for the treatment of LNM+ OSCC via targeting IRF2BP2-FAO.

Identification and validation of novel prognostic fatty acid metabolic gene signatures in colon adenocarcinoma through systematic approaches

Background

Colorectal cancer (CRC) belongs to the class of significantly malignant tumors found in humans. Recently, dysregulated fatty acid metabolism (FAM) has been a topic of attention due to its modulation in cancer, specifically CRC. However, the regulatory FAM pathways in CRC require comprehensive elucidation.

Methods

The clinical and gene expression data of 175 fatty acid metabolic genes (FAMGs) linked with colon adenocarcinoma (COAD) and normal cornerstone genes were gathered through The Cancer Genome Atlas (TCGA)-COAD corroborating with the Molecular Signature Database v7.2 (MSigDB). Initially, crucial prognostic genes were selected by uni- and multi-variate Cox proportional regression analyses; then, depending upon these identified signature genes and clinical variables, a nomogram was generated. Lastly, to assess tumor immune characteristics, concomitant evaluation of tumor immune evasion/risk scoring were elucidated.

Results

A 8-gene signature, including ACBD4, ACOX1, CD36, CPT2, ELOVL3, ELOVL6, ENO3, and SUCLG2, was generated, and depending upon this, CRC patients were categorized within high-risk (H-R) and low-risk (L-R) cohorts. Furthermore, risk and age-based nomograms indicated moderate discrimination and good calibration. The data confirmed that the 8-gene model efficiently predicted CRC patients' prognosis. Moreover, according to the conjoint analysis of tumor immune evasion and the risk scorings, the H-R cohort had an immunosuppressive tumor microenvironment, which caused a substandard prognosis.

Conclusion

This investigation established a FAMGs-based prognostic model with substantially high predictive value, providing the possibility for improved individualized treatment for CRC individuals.

Transcriptome-wide N6-methyladenosine methylation profile of atherosclerosis in mice

BACKGROUND

Atherosclerosis (AS) is a critical pathological event during the progression of cardiovascular diseases. It exhibits fibrofatty lesions on the arterial wall and lacks effective treatment. N6-methyladenosine (m6A) is the most common modification of eukaryotic RNA and plays an important role in regulating the development and progression of cardiovascular diseases. However, the role of m6A modification in AS remains largely unknown. Therefore, in this study, we explored the transcriptome distribution of m6A modification in AS and its potential mechanism.

METHODS

Methylation Quantification Kit was used to detect the global m6A levels in the aorta of AS mice. Western blot was used to analyze the protein level of methyltransferases. Methylated RNA immunoprecipitation with next-generation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were used to obtain the first transcriptome range analysis of the m6A methylene map in the aorta of AS mice, followed by bioinformatics analysis. qRT-PCR and MeRIP-qRT-PCR were used to measure the mRNA and m6A levels in target genes.

RESULTS

The global m6A and protein levels of methyltransferase METTL3 were significantly increased in the aorta of AS mice. However, the protein level of demethylase ALKBH5 was significantly decreased. Through MeRIP-seq, we obtained m6A methylation maps in AS and control mice. In total, 26,918 m6A peaks associated with 13,744 genes were detected in AS group, whereas 26,157 m6A peaks associated with 13,283 genes were detected in the control group. Peaks mainly appeared in the coding sequence (CDS) regions close to the stop codon with the RRACH motif. Moreover, functional enrichment analysis demonstrated that m6A-containing genes were significantly enriched in AS-relevant pathways. Interestingly, a negative correlation between m6A methylation abundance and gene expression level was found through the integrated analysis of MeRIP-seq and RNA-seq data. Among the m6A-modified genes, a hypo-methylated but up-regulated (hypo-up) gene Fabp5 may be a potential biomarker of AS.

CONCLUSIONS

Our study provides transcriptome-wide m6A methylation for the first time to determine the association between m6A modification and AS progression. Our study lays a foundation for further exploring the pathogenesis of AS and provides a new direction for the treatment of AS.

Interleukin-10 increases macrophage-mediated chemotherapy resistance via FABP5 signaling in multiple myeloma

Macrophages (MΦs) protect multiple myeloma (MM) cells from chemotherapy-induced apoptosis, and interleukin-10 (IL-10) is frequently elevated in the MM microenvironment. However, the role of IL-10 in MΦ-induced tumor chemotherapy resistance has not yet been clarified. In the present study, bone marrow-derived MΦs were treated with IL-10 (IL10-MΦs), and IL10-MΦ-induced MM chemotherapy resistance was evaluated. IL-10 promoted MΦ-mediated resistance to MM chemotherapy. In addition, IL-10 treatment increased lipid accumulation and fatty acid β-oxidation in MΦs. Mechanistically, IL-10 increased fatty acid binding protein 5 (FABP5) expression in MΦs, and targeting FABP5 decreased MM chemotherapy resistance induced by IL10-MΦs in vitro and enhanced chemotherapeutic efficacy in vivo. Inhibition of FABP5 decreased the expression of Carnitine Palmitoyltransferase 1A (CPT1A) in IL10-MΦs. In addition, inhibition of CPT1A in IL10-MΦs decreased IL10-MΦ-mediated MM chemotherapy resistance. Peroxisome proliferator-activated receptor γ (PPARγ) is upstream of FABP5 signaling. Inhibition of PPARγ in IL10-MΦs decreased IL10-MΦ-mediated MM chemotherapy resistance in vitro. Collectively, our work indicates that IL-10 enhances MΦ-mediated MM chemotherapy resistance via FABP5 signaling and targeting FABP5 has potentially important clinical implications.

Multidimensional outlook on the pathophysiology of cervical cancer invasion and metastasis

Cervical cancer being one of the primary causes of high mortality rates among women is an area of concern, especially with ineffective treatment strategies. Extensive studies are carried out to understand various aspects of cervical cancer initiation, development and progression; however, invasive cervical squamous cell carcinoma has poor outcomes. Moreover, the advanced stages of cervical cancer may involve lymphatic circulation with a high risk of tumor recurrence at distant metastatic sites. Dysregulation of the cervical microbiome by human papillomavirus (HPV) together with immune response modulation and the occurrence of novel mutations that trigger genomic instability causes malignant transformation at the cervix. In this review, we focus on the major risk factors as well as the functionally altered signaling pathways promoting the transformation of cervical intraepithelial neoplasia into invasive squamous cell carcinoma. We further elucidate genetic and epigenetic variations to highlight the complexity of causal factors of cervical cancer as well as the metastatic potential due to the changes in immune response, epigenetic regulation, DNA repair capacity, and cell cycle progression. Our bioinformatics analysis on metastatic and non-metastatic cervical cancer datasets identified various significantly and differentially expressed genes as well as the downregulation of potential tumor suppressor microRNA miR-28-5p. Thus, a comprehensive understanding of the genomic landscape in invasive and metastatic cervical cancer will help in stratifying the patient groups and designing potential therapeutic strategies.

Liquid-liquid phase separation-related gene in gliomas: FABP5 is a potential prognostic marker

BACKGROUND

The glioma is the most malignant human brain tumor. Early glioma detection and treatment are still difficult. New biomarkers are desperately required to aid in the evaluation of diagnosis and prognosis.

METHODS

The single cell sequencing dataset scRNA-6148 for glioblastoma was obtained from the Chinese Glioma Genome Atlas database. Data were gathered for the transcriptome sequencing project. Genes involved in liquid-liquid phase separation (LLPS) were taken out of the DrLLPS database. To find the modules connected to LLPS, the weighted co-expression network was analyzed. Differential expression analysis was used to identify the differentially expressed genes (DEGs) in gliomas. Pseudo-time series analysis, gene set enrichment analysis (GSEA) and immune cell infiltration analysis were used to investigate the role of important genes in the immunological microenvironment. We examined the function of key glioma genes using polymerase chain reaction (PCR) testing, CCK-8 assays, clone generation assays, transwell assays and wound healing assays.

RESULTS

FABP5 was identified as a key gene in glioblastoma by multiomics research. Pseudo-time series analysis showed that FABP5 was highly linked with the differentiation of many different types of cells. GSEA revealed that FABP5 was strongly linked to several hallmark pathways in glioblastoma. We looked at immune cell infiltration and discovered a significant link between FABP5, macrophages and T cell follicular helpers. The PCR experiment results demonstrated that FABP5 expression was elevated in glioma samples. Cell experiments showed that FABP5 knockdown dramatically decreased the viability, proliferation, invasion and migration of the LN229 and U87 glioma cell lines.

CONCLUSIONS

Our study provides a new biomarker, FABP5, for glioma diagnosis and treatment.

Whole genome methylation sequencing reveals epigenetic landscape and abnormal expression of FABP5 in extramammary Paget's disease

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare cutaneous malignant tumor with a high recurrence rate after surgery. However, the genetic and epigenetic alterations underlying its pathogenesis remain unknown. DNA methylation is an important epigenetic modification involved in many biological processes.

METHODS

In this study, enzymatic methyl-sequencing (EM-seq) technique was used to investigate the landscape of genome-wide DNA methylation from three pairs of tumor tissues and adjacent tissues of patients with EMPD. Additionally, we conducted histopathological examinations to assess the expression of fatty acid-binding protein 5 (FABP5) in another three paired samples from EMPD patients.

RESULTS

The cluster analysis showed the good quality of the samples. A differential methylation region (DMR) heat map was used to quantitatively characterize genome-wide methylation differences between tumors and controls. Global DNA methylation level is lower in EMPD tissue compared to matched controls, indicating that DNA methylation discriminates between tumor and normal skin. And the top hypomethylation gene on the promoter region in tumor tissues was FABP5 on chromosome 8 with 38.44% decreased median methylation. We next identified the expression of FABP5 in paired tumors and adjacent tissues in three additional patients with EMPD. Immunofluorescence results showed FABP5 highly expressed in tumor tissues and co-located with CK7, CK20 and EMA. GO and KEGG enrichment analysis showed DMR genes on promoter are mainly enriched in the calcium ion transport, GTPase mediated signal transduction, Rap1 signaling pathway and GnRH signaling pathway.

CONCLUSION

Taken together, our findings provide the first description of the whole genome methylation map of EMPD and identify FABP5 as a pathogenic target of EMPD.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

GPX8 regulates pan-apoptosis in gliomas to promote microglial migration and mediate immunotherapy responses

Introduction

Gliomas have emerged as the predominant brain tumor type in recent decades, yet the exploration of non-apoptotic cell death regulated by the pan-optosome complex, known as pan-apoptosis, remains largely unexplored in this context. This study aims to illuminate the molecular properties of pan-apoptosis-related genes in glioma patients, classifying them and developing a signature using machine learning techniques.

Methods

The prognostic significance, mutation features, immunological characteristics, and pharmaceutical prediction performance of this signature were comprehensively investigated. Furthermore, GPX8, a gene of interest, was extensively examined for its prognostic value, immunological characteristics, medication prediction performance, and immunotherapy prediction potential.

Results

Experimental techniques such as CCK-8, Transwell, and EdU investigations revealed that GPX8 acts as a tumor accelerator in gliomas. At the single-cell RNA sequencing level, GPX8 appeared to facilitate cell contact between tumor cells and macrophages, potentially enhancing microglial migration.

Conclusions

The incorporation of pan-apoptosis-related features shows promising potential for clinical applications in predicting tumor progression and advancing immunotherapeutic strategies. However, further in vitro and in vivo investigations are necessary to validate the tumorigenic and immunogenic processes associated with GPX8 in gliomas.

Lipid metabolic reprogramming in tumor microenvironment: from mechanisms to therapeutics

Lipid metabolic reprogramming is an emerging hallmark of cancer. In order to sustain uncontrolled proliferation and survive in unfavorable environments that lack oxygen and nutrients, tumor cells undergo metabolic transformations to exploit various ways of acquiring lipid and increasing lipid oxidation. In addition, stromal cells and immune cells in the tumor microenvironment also undergo lipid metabolic reprogramming, which further affects tumor functional phenotypes and immune responses. Given that lipid metabolism plays a critical role in supporting cancer progression and remodeling the tumor microenvironment, targeting the lipid metabolism pathway could provide a novel approach to cancer treatment. This review seeks to: (1) clarify the overall landscape and mechanisms of lipid metabolic reprogramming in cancer, (2) summarize the lipid metabolic landscapes within stromal cells and immune cells in the tumor microenvironment, and clarify their roles in tumor progression, and (3) summarize potential therapeutic targets for lipid metabolism, and highlight the potential for combining such approaches with other anti-tumor therapies to provide new therapeutic opportunities for cancer patients.

New mechanisms and biomarkers of lymph node metastasis in cervical cancer: reflections from plasma proteomics

OBJECTIVE

Lymph node metastasis (LNM) and lymphatic vasculature space infiltration (LVSI) in cervical cancer patients indicate a poor prognosis, but satisfactory methods for diagnosing these phenotypes are lacking. This study aimed to find new effective plasma biomarkers of LNM and LVSI as well as possible mechanisms underlying LNM and LVSI through data-independent acquisition (DIA) proteome sequencing.

METHODS

A total of 20 cervical cancer plasma samples, including 7 LNM-/LVSI-(NC), 4 LNM-/LVSI + (LVSI) and 9 LNM + /LVSI + (LNM) samples from a cohort, were subjected to DIA to identify differentially expressed proteins (DEPs) for LVSI and LNM. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed for DEP functional annotation. Protein-protein interaction (PPI) and weighted gene coexpression network analysis (WGCNA) were used to detect new effective plasma biomarkers and possible mechanisms.

RESULTS

A total of 79 DEPs were identified in the cohort. GO and KEGG analyses showed that DEPs were mainly enriched in the complement and coagulation pathway, lipid and atherosclerosis pathway, HIF-1 signal transduction pathway and phagosome and autophagy. WGCNA showed that the enrichment of the green module differed greatly between groups. Six interesting core DEPs (SPARC, HPX, VCAM1, TFRC, ERN1 and APMAP) were confirmed to be potential plasma diagnostic markers for LVSI and LNM in cervical cancer patients.

CONCLUSION

Proteomic signatures developed in this study reflected the potential plasma diagnostic markers and new possible pathogenesis mechanisms in the LVSI and LNM of cervical cancer.

FABP5 regulates lipid metabolism to facilitate pancreatic neuroendocrine neoplasms progression via FASN mediated Wnt/β-catenin pathway

Pancreatic neuroendocrine neoplasms (pNENs) are among the most frequently occurring neuroendocrine neoplasms (NENs) and require targeted therapy. High levels of fatty acid binding protein 5 (FABP5) are involved in tumor progression, but its role in pNENs remains unclear. We investigated the mRNA and protein levels of FABP5 in pNEN tissues and cell lines and found them to be upregulated. We evaluated changes in cell proliferation using CCK-8, colony formation, and 5-ethynyl-2'-deoxyuridine assays and examined the effects on cell migration and invasion using transwell assays. We found that knockdown of FABP5 suppressed the proliferation, migration, and invasion of pNEN cell lines, while overexpression of FABP5 had the opposite effect. Co-immunoprecipitation experiments were performed to clarify the interaction between FABP5 and fatty acid synthase (FASN). We further showed that FABP5 regulates the expression of FASN via the ubiquitin proteasome pathway and both proteins facilitate the progression of pNENs. Our study demonstrated that FABP5 acts as an oncogene by promoting lipid droplet deposition and activating the WNT/β-catenin signaling pathway. Moreover, the carcinogenic effects of FABP5 can be reversed by orlistat, providing a novel therapeutic intervention option.

Exosomal ACADM sensitizes gemcitabine-resistance through modulating fatty acid metabolism and ferroptosis in pancreatic cancer

This study aimed to evaluate the potential of exosomes from cancer cells to predict chemoresistance in pancreatic cancer (PC) and explore the molecular mechanisms through RNA-sequencing and mass spectrometry. We sought to understand the connection between the exosomal Medium-chain acyl-CoA dehydrogenase (ACADM) level and the reaction to gemcitabine in vivo and in patients with PC. We employed loss-of-function, gain-of-function, metabolome mass spectrometry, and xenograft models to investigate the effect of exosomal ACADM in chemoresistance in PC. Our results showed that the molecules involved in lipid metabolism in exosomes vary between PC cells with different gemcitabine sensitivity. Exosomal ACADM (Exo-ACADM) was strongly correlated with gemcitabine sensitivity in vivo, which can be used as a predictor for postoperative gemcitabine chemosensitivity in pancreatic patients. Moreover, ACADM was found to regulate the gemcitabine response by affecting ferroptosis through Glutathione peroxidase 4 (GPX4) and mevalonate pathways. It was also observed that ACADM increased the consumption of unsaturated fatty acids and decreased intracellular lipid peroxides and reactive oxygen species (ROS) levels. In conclusion, this research suggests that Exo-ACADM may be a viable biomarker for predicting the responsiveness of patients to chemotherapy.

Doxorubicin resistance in breast cancer is mediated via the activation of FABP5/PPARγ and CaMKII signaling pathway

Breast cancer is the most prevalent malignancy among women. Doxorubicin (Dox) resistance was one of the major obstacles to improving the clinical outcome of breast cancer patients. The purpose of this study was to investigate the relationship between the FABP signaling pathway and Dox resistance in breast cancer. The resistance property of MCF-7/ADR cells was evaluated employing CCK-8, Western blot (WB), and confocal microscopy techniques. The glycolipid metabolic properties of MCF-7 and MCF-7/ADR cells were identified using transmission electron microscopy, PAS, and Oil Red O staining. FABP5 and CaMKII expression levels were assessed through GEO and WB approaches. The intracellular calcium level was determined by flow cytometry. Clinical breast cancer patient's tumor tissues were evaluated by immunohistochemistry to determine FABP5 and p-CaMKII protein expression. In the presence or absence of FABP5 siRNA or the FABP5-specific inhibitor SBFI-26, Dox resistance was investigated utilizing CCK-8, WB, and colony formation methods, and intracellular calcium level was examined. The binding ability of Dox was explored by molecular docking analysis. The results indicated that the MCF-7/ADR cells we employed were Dox-resistant MCF-7 cells. FABP5 expression was considerably elevated in MCF-7/ADR cells compared to parent MCF-7 cells. FABP5 and p-CaMKII expression were increased in resistant patients than in sensitive individuals. Inhibition of the protein expression of FABP5 by siRNA or inhibitor increased Dox sensitivity in MCF-7/ADR cells and lowered intracellular calcium, PPARγ, and autophagy. Molecular docking results showed that FABP5 binds more powerfully to Dox than the known drug resistance-associated protein P-GP. In summary, the PPARγ and CaMKII axis mediated by FABP5 plays a crucial role in breast cancer chemoresistance. FABP5 is a potentially targetable protein and therapeutic biomarker for the treatment of Dox resistance in breast cancer.

Delineation of fatty acid metabolism in gastric cancer: Therapeutic implications

BACKGROUND

The prognosis of gastric cancer is extremely poor. Metabolic reprogramming involving lipids has been associated with cancer occurrence and progression.

AIM

To illustrate fatty acid metabolic mechanisms in gastric cancer, detect core genes, develop a prognostic model, and provide treatment options.

METHODS

Raw data from The Cancer Genome Atlas and Gene Expression Omnibus databases were collected and analyzed. Differentially expressed fatty acid metabolism genes were identified and incorporated into a risk model based on least absolute shrinkage and selection operator regression analysis. Then, patients from The Cancer Genome Atlas were assigned to high- and low-risk cohorts according to the mean value of the risk score as the threshold, which was verified in the Gene Expression Omnibus database. Relationships between chemotherapeutic sensitivity and tumor microenvironment features were assessed.

RESULTS

An integrated evaluation was performed in this study. Fatty acid metabolism-related genes were used to construct the risk model. Patients classified into the high-risk cohort were considered to be resistant to chemotherapy based on results of the "pRRophetic" R package. Patients in the high-risk cohort were associated with type I/II interferon activation, increased inflammation level, immune cell infiltration, and tumor immune dysfunction based on the exclusion algorithm, indicating the potential benefit of immunotherapy in these patients.

CONCLUSION

We constructed a fatty acid-related risk score model to assess the comprehensive fatty acid features in gastric cancer and validated its vital role in prognosis, chemotherapy sensitivity, and immunotherapy.

Delineation of fatty acid metabolism in gastric cancer: Therapeutic implications

BACKGROUND

The prognosis of gastric cancer is extremely poor. Metabolic reprogramming involving lipids has been associated with cancer occurrence and progression.

AIM

To illustrate fatty acid metabolic mechanisms in gastric cancer, detect core genes, develop a prognostic model, and provide treatment options.

METHODS

Raw data from The Cancer Genome Atlas and Gene Expression Omnibus databases were collected and analyzed. Differentially expressed fatty acid metabolism genes were identified and incorporated into a risk model based on least absolute shrinkage and selection operator regression analysis. Then, patients from The Cancer Genome Atlas were assigned to high- and low-risk cohorts according to the mean value of the risk score as the threshold, which was verified in the Gene Expression Omnibus database. Relationships between chemotherapeutic sensitivity and tumor microenvironment features were assessed.

RESULTS

An integrated evaluation was performed in this study. Fatty acid metabolism-related genes were used to construct the risk model. Patients classified into the high-risk cohort were considered to be resistant to chemotherapy based on results of the “pRRophetic” R package. Patients in the high-risk cohort were associated with type I/II interferon activation, increased inflammation level, immune cell infiltration, and tumor immune dysfunction based on the exclusion algorithm, indicating the potential benefit of immunotherapy in these patients.

CONCLUSION

We constructed a fatty acid-related risk score model to assess the comprehensive fatty acid features in gastric cancer and validated its vital role in prognosis, chemotherapy sensitivity, and immunotherapy.

FAM201A encodes small protein NBASP to inhibit neuroblastoma progression via inactivating MAPK pathway mediated by FABP5

Increasing evidence indicates that long non-coding RNA (lncRNA) is one of the most important RNA regulators in the pathogenesis of neuroblastoma (NB). Here, we found that FAM201A was low expressed in NB and a variety of gain and loss of function studies elucidated the anti-tumor effects of FAM201A on the regulation of proliferation, migration and invasion of NB cells. Intriguingly, we identified the ability of FAM201A to encode the tumor-suppressing protein, NBASP, which interacted with FABP5 and negatively regulated its expression. In vivo assays also revealed NBASP repressed NB growth via inactivating MAPK pathway mediated by FABP5. In conclusion, our findings demonstrated that NBASP encoded by FAM201A played a tumor-suppressor role in NB carcinogenesis via down-regulating FABP5 to inactivate the MAPK pathway. These results extended our understanding of the relationship of lncRNA-encoded functional peptides and plasticity of tumor progression.

Aberrant DNA methylation-mediated NF-κB/fatty acid-binding protein 5 (FABP5) feed-forward loop promotes malignancy of colorectal cancer cells

Fatty acid-binding proteins (FABPs) are intracellular lipid-binding proteins that play roles in fatty acid transport and the regulation of gene expression. Dysregulated FABP expression and/or activity have been associated with cancer pathogenesis; in particular, epidermal-type FABP (FABP5) is upregulated in many types of cancer. However, the mechanisms regulating FABP5 expression and its involvement in cancer remain largely unknown. Here, we examined the regulation of FABP5 gene expression in non-metastatic and metastatic human colorectal cancer (CRC) cells. We found that FABP5 expression was upregulated in metastatic compared with non-metastatic CRC cells as well as in human CRC tissues compared with adjacent normal tissue. Analysis of the DNA methylation status of the FABP5 promoter showed that hypomethylation correlated with the malignant potential of the CRC cell lines. Moreover, FABP5 promoter hypomethylation also correlated with the expression pattern of splice variants of the DNA methyltransferase DNMT3B. ChIP assays and luciferase reporter assays demonstrated that the transcription factor nuclear factor-kappa B (NF-κB) was involved in regulating FABP5 expression. FABP5 expression could be upregulated in metastatic CRC cells by sequential promotion of DNA demethylation followed by activation of NF-κB. We also found that upregulated FABP5 in turn controlled NF-κB activity through IL-8 production. Collectively, these findings suggest the existence of a DNA methylation-dependent NF-κB /FABP5 positive feed-forward loop that may lead to constitutive activation of NF-κB signaling pathway and play a crucial role in CRC progression.

FABP5 suppresses colorectal cancer progression via mTOR-mediated autophagy by decreasing FASN expression

Lipid metabolism plays an important role in the occurrence and development of cancer, in particular, digestive system tumors such as colon cancer. Here, we investigated the role of the fatty acid-binding protein 5 (FABP5) in colorectal cancer (CRC). We observed marked down-regulation of FABP5 in CRC. Data from functional assays revealed inhibitory effects of FABP5 on cell proliferation, colony formation, migration, invasion as well as tumor growth in vivo. In terms of mechanistic insights, FABP5 interacted with fatty acid synthase (FASN) and activated the ubiquitin proteasome pathway, leading to a decrease in FASN expression and lipid accumulation, moreover, suppressing mTOR signaling and facilitating cell autophagy. Orlistat, a FASN inhibitor, exerted anti-cancer effects both in vivo and in vitro. Furthermore, the upstream RNA demethylase ALKBH5 positively regulated FABP5 expression via an m⁶A-independent mechanism. Overall, our collective findings offer valuable insights into the critical role of the ALKBH5/FABP5/FASN/mTOR axis in tumor progression and uncover a potential mechanism linking lipid metabolism to development of CRC, providing novel therapeutic targets for future interventions.

The emerging role of fatty acid binding protein 5 (FABP5) in cancers

Fatty acid binding protein 5 (FABP5, or epidermal FABP) is an intracellular chaperone of fatty acid molecules that regulates lipid metabolism and cell growth. In patient-derived tumours, FABP5 expression is increased up to tenfold, often co-expressed with other cancer-related proteins. High tumoral FABP5 expression is associated with poor prognosis. FABP5 activates transcription factors (TFs) leading to increased expression of proteins involved in tumorigenesis. Genetic and pharmacological preclinical studies show that inhibiting FABP5 reduces protumoral markers, whereas elevation of FABP5 promotes tumour growth and spread. Thus, FABP5 might be a valid target for novel therapeutics. The evidence base is currently strongest for liver, prostate, breast, and brain cancers, and squamous cell carcinoma (SCC), which could represent relevant patient populations for any drug discovery programme. Teaser: This review presents the growing evidence that upregulated fatty acid binding protein 5 (FABP5) plays a role in the progression of multiple cancer types, and may represent a novel therapeutic target.

Tumor microenvironment promotes lymphatic metastasis of cervical cancer: its mechanisms and clinical implications

Although previous studies have shed light on the etiology of cervical cancer, metastasis of advanced cervical cancer remains the main reason for the poor outcome and high cancer-related mortality rate. Cervical cancer cells closely communicate with immune cells recruited to the tumor microenvironment (TME), such as lymphocytes, tumor-associated macrophages, and myeloid-derived suppressor cells. The crosstalk between tumors and immune cells has been clearly shown to foster metastatic dissemination. Therefore, unraveling the mechanisms of tumor metastasis is crucial to develop more effective therapies. In this review, we interpret several characteristics of the TME that promote the lymphatic metastasis of cervical cancer, such as immune suppression and premetastatic niche formation. Furthermore, we summarize the complex interactions between tumor cells and immune cells within the TME, as well as potential therapeutic strategies to target the TME.

Identification and validation of fatty acid metabolism-related lncRNA signatures as a novel prognostic model for clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a main subtype of renal cancer, and advanced ccRCC frequently has poor prognosis. Many studies have found that lipid metabolism influences tumor development and treatment. This study was to examine the prognostic and functional significance of genes associated with lipid metabolism in individuals with ccRCC. Using the database TCGA, differentially expressed genes (DEGs) associated with fatty acid metabolism (FAM) were identified. Prognostic risk score models for genes related to FAM were created using univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses. Our findings demonstrate that the prognosis of patients with ccRCC correlate highly with the profiles of FAM-related lncRNAs (AC009166.1, LINC00605, LINC01615, HOXA-AS2, AC103706.1, AC009686.2, AL590094.1, AC093278.2). The prognostic signature can serve as an independent predictive predictor for patients with ccRCC. The predictive signature's diagnostic effectiveness was superior to individual clinicopathological factors. Between the low- and high-risk groups, immunity research revealed a startling difference in terms of cells, function, and checkpoint scores. Chemotherapeutic medications such lapatinib, AZD8055, and WIKI4 had better outcomes for patients in the high-risk group. Overall, the predictive signature can help with clinical selection of immunotherapeutic regimens and chemotherapeutic drugs, improving prognosis prediction for ccRCC patients.

A novel Alzheimer's disease prognostic signature: identification and analysis of glutamine metabolism genes in immunogenicity and immunotherapy efficacy

Alzheimer's disease (AD) is characterized as a distinct onset and progression of cognitive and functional decline associated with age, as well as a specific neuropathology. It has been discovered that glutamine (Gln) metabolism plays a crucial role in cancer. However, a full investigation of its role in Alzheimer's disease is still missing. This study intended to find and confirm potential Gln-related genes associated with AD using bioinformatics analysis. The discovery of GlnMgs was made possible by the intersection of the WGCNA test and 26 Gln-metabolism genes (GlnMgs). GlnMgs' putative biological functions and pathways were identified using GSVA. The LASSO method was then used to identify the hub genes as well as the diagnostic efficiency of the four GlnMgs in identifying AD. The association between hub GlnMgs and clinical characteristics was also studied. Finally, the GSE63060 was utilized to confirm the levels of expression of the four GlnMgs. Four GlnMgs were discovered (ATP5H, NDUFAB1, PFN2, and SPHKAP). For biological function analysis, cell fate specification, atrioventricular canal development, and neuron fate specification were emphasized. The diagnostic ability of the four GlnMgs in differentiating AD exhibited a good value. This study discovered four GlnMgs that are linked to AD. They shed light on potential new biomarkers for AD and tracking its progression.

Specific regulation of BACH1 by the hotspot mutant p53R175H reveals a distinct gain-of-function mechanism

Although the gain of function (GOF) of p53 mutants is well recognized, it remains unclear whether different p53 mutants share the same cofactors to induce GOFs. In a proteomic screen, we identified BACH1 as a cellular factor that recognizes the p53 DNA-binding domain depending on its mutation status. BACH1 strongly interacts with p53R175H but fails to effectively bind wild-type p53 or other hotspot mutants in vivo for functional regulation. Notably, p53R175H acts as a repressor for ferroptosis by abrogating BACH1-mediated downregulation of SLC7A11 to enhance tumor growth; conversely, p53R175H promotes BACH1-dependent tumor metastasis by upregulating expression of pro-metastatic targets. Mechanistically, p53R175H-mediated bidirectional regulation of BACH1 function is dependent on its ability to recruit the histone demethylase LSD2 to target promoters and differentially modulate transcription. These data demonstrate that BACH1 acts as a unique partner for p53R175H in executing its specific GOFs and suggest that different p53 mutants induce their GOFs through distinct mechanisms.

Fatty Acid Binding Protein 5 (FABP5) Promotes Aggressiveness of Gastric Cancer Through Modulation of Tumor Immunity

PURPOSE

Gastric cancer (GC) is the second most lethal cancer globally and is associated with poor prognosis. Fatty acid-binding proteins (FABPs) can regulate biological properties of carcinoma cells. FABP5 is overexpressed in many types of cancers; however, the role and mechanisms of action of FABP5 in GC remain unclear. In this study, we aimed to evaluate the clinical and biological functions of FABP5 in GC.

MATERIALS AND METHODS

We assessed FABP5 expression using immunohistochemical analysis in 79 patients with GC and evaluated its biological functions following in vitro and in vivo ectopic expression. FABP5 targets relevant to GC progression were determined using RNA sequencing (RNA-seq).

RESULTS

Elevated FABP5 expression was closely associated with poor outcomes, and ectopic expression of FABP5 promoted proliferation, invasion, migration, and carcinogenicity of GC cells, thus suggesting its potential tumor-promoting role in GC. Additionally, RNA-seq analysis indicated that FABP5 activates immune-related pathways, including cytokine-cytokine receptor interaction pathways, interleukin-17 signaling, and tumor necrosis factor signaling, suggesting an important rationale for the possible development of therapies that combine FABP5-targeted drugs with immunotherapeutics.

CONCLUSIONS

These findings highlight the biological mechanisms and clinical implications of FABP5 in GC and suggest its potential as an adverse prognostic factor and/or therapeutic target.

Fatty acid metabolism: A new therapeutic target for cervical cancer

Cervical cancer (CC) is one of the most common malignancies in women. Cancer cells can use metabolic reprogramming to produce macromolecules and ATP needed to sustain cell growth, division and survival. Recent evidence suggests that fatty acid metabolism and its related lipid metabolic pathways are closely related to the malignant progression of CC. In particular, it involves the synthesis, uptake, activation, oxidation, and transport of fatty acids. Similarly, more and more attention has been paid to the effects of intracellular lipolysis, transcriptional regulatory factors, other lipid metabolic pathways and diet on CC. This study reviews the latest evidence of the link between fatty acid metabolism and CC; it not only reveals its core mechanism but also discusses promising targeted drugs for fatty acid metabolism. This study on the complex relationship between carcinogenic signals and fatty acid metabolism suggests that fatty acid metabolism will become a new therapeutic target in CC.

Lycorine induces apoptosis of acute myeloid leukemia cells and inhibits triglyceride production via binding and targeting FABP5

Acute myeloid leukemia (AML) is the most common hematopoietic malignancy with abnormal lipid metabolism. However, currently available information on the involvement of the alterations in lipid metabolism in AML development is limited. In this study, we demonstrate that FABP5 expression facilitates AML cell viability, protects AML cells from apoptosis, and maintains triglyceride production. Our bioinformatics analysis revealed that FABP5 expression was upregulated and correlated with unfavorable overall survival of AML patients. FABP5 expression may be used to distinguish normal and AML with high accuracy. FABP5-based risk score was an independent risk factor for AML patients. AML patients with highly expressed FABP5 predicted resistance to drugs. In vitro study showed that FABP5 expression was remarkably elevated in primary AML blasts and an AML cell line. Silencing FABP5 expression attenuated AML cell viability, reduced triglyceride production and lipid droplet accumulation, and induced apoptosis. We utilized AutoDock online tool to identify lycorine as an FABP5 inhibitor by binding FABP5 at amino acid residues Ile54, Thr56, Thr63, and Arg109. Lycorine treatment downregulated the expression levels of FABP5 and its target PPARγ, impaired AML cell viability, triggered apoptosis, and reduced triglyceride production in AML cells. These results demonstrate that FABP5 is critical for AML cell survival and highlight a novel metabolic vulnerability for AML.

Oncogenic role and potential regulatory mechanism of fatty acid binding protein 5 based on a pan-cancer analysis

As one member of fatty acid binding proteins (FABPs), FABP5 makes a contribution in the occurrence and development of several tumor types, but existing analysis about FABP5 and FABP5-related molecular mechanism remains limited. Meanwhile, some tumor patients showed limited response rates to current immunotherapy, and more potential targets need to be explored for the improvement of immunotherapy. In this study, we made a pan-cancer analysis of FABP5 based on the clinical data from The Cancer Genome Atlas database for the first time. FABP5 overexpression was observed in many tumor types, and was statistically associated with poor prognosis of several tumor types. Additionally, we further explored FABP5-related miRNAs and corresponding lncRNAs. Then, miR-577-FABP5 regulatory network in kidney renal clear cell carcinoma as well as CD27-AS1/GUSBP11/SNHG16/TTC28-AS1-miR-22-3p-FABP5 competing endogenous RNA regulatory network in liver hepatocellular carcinoma were constructed. Meanwhile, Western Blot and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis were used to verify miR-22-3p-FABP5 relationship in LIHC cell lines. Moreover, the potential relationships of FABP5 with immune infiltration and six immune checkpoints (CD274, CTLA4, HAVCR2, LAG3, PDCD1 and TIGIT) were discovered. Our work not only deepens the understanding of FABP5's functions in multiple tumors and supplements existing FABP5-related mechanisms, but also provides more possibilities for immunotherapy.