Fatty Acid Synthase and Acetyl-CoA Carboxylase Are Expressed in Nodal Metastatic Melanoma But Not in Benign Intracapsular Nodal Nevi

Fatty Acid Metabolism-Related lncRNAs are Potential Biomarkers for Predicting Prognoses and Immune Responses in Patients with Skin Cutaneous Melanoma

Introduction

Skin cutaneous melanoma is becoming more dangerous since it has a poor prognosis and is resistant to treatment. Previous research has shown that lncRNAs and fatty acid metabolism are essential for numerous biological activities. There are no studies on the relationship between fatty acid metabolism-Related lncRNAs and skin cutaneous melanoma.

Methods and Results

In order to better understand the prognosis and survival of SKCM patients, we investigated the significance of lncRNAs related to fatty acid metabolism. In this work, we looked at the fatty acid metabolism genes and lncRNAs expression patterns. On the basis of lncRNAs associated with fatty acid metabolism, a nomogram and a prognosis prediction model were created. Based on the profile of lncRNAs associated with fatty acid metabolism, functional and pharmacological sensitivity investigations were also carried out. We also looked at the connection between immunotherapy and the immune response. The findings demonstrated that a risk score model based on 11 essential lncRNAs for fatty acid metabolism may discriminate between the clinical condition of SKCM and more accurately predict prognosis and survival. We conducted quantitative reverse transcription polymerase-chain reaction (RT-PCR) to verify the model.

Conclusion

These important lncRNAs further showed a strong association with the tumor immune system, and these important lncRNAs also showed a connection between SKCM and chemotherapeutic treatment sensitivity. Our research strives to provide fresh viewpoints and innovative approaches to the treatment and administration of SKCM.

Biological Role and Mechanism of Lipid Metabolism Reprogramming Related Gene ECHS1 in Cancer

Cancer is a major threat to human health today. Although the existing anticancer treatments have effectively improved the prognosis of some patients, there are still other patients who cannot benefit from these well-established strategies. Reprogramming of lipid metabolism is one of the typical features of cancers. Recent studies have revealed that key enzymes involved in lipid metabolism may be effective anticancer therapeutic targets, but the development of therapeutic lipid metabolism targets is still insufficient. ECHS1 (enoyl-CoA hydratase, short chain 1) is a key enzyme mediating the hydration process of mitochondrial fatty acid β-oxidation and has been observed to be abnormally expressed in a variety of cancers. Therefore, with ECHS1 and cancer as the main keywords, we searched the relevant studies of ECHS1 in the field of cancer in Pubmed, summarized the research status and functions of ECHS1 in different cancer contexts, and explored its potential regulatory mechanisms, with a view to finding new therapeutic targets for anti-metabolic therapy. By reviewing and summarizing the retrieved literatures, we found that ECHS1 regulates malignant biological behaviors such as cell proliferation, metastasis, apoptosis, autophagy, and drug resistance by remodeling lipid metabolism and regulating intercellular oncogenic signaling pathways. Not only that, ECHS1 exhibits early diagnostic and prognostic value in clear cell renal cell carcinoma, and small-molecule inhibitors that regulate ECHS1 also show therapeutic significance in preclinical studies. Taken together, we propose that ECHS1 has the potential to serve as a therapeutic target of lipid metabolism.

Proteomics and metabolomics approach in adult and pediatric glioma diagnostics

The diagnosis of glioma is mainly based on imaging methods that do not distinguish between stage and subtype prior to histopathological analysis. Patients with gliomas are generally diagnosed in the symptomatic stage of the disease. Additionally, healing scar tissue may be mistakenly identified based on magnetic resonance imaging (MRI) as a false positive tumor recurrence in postoperative patients. Current knowledge of molecular alterations underlying gliomagenesis and identification of tumoral biomarkers allow for their use as discriminators of the state of the organism. Moreover, a multiomics approach provides the greatest spectrum and the ability to track physiological changes and can serve as a minimally invasive method for diagnosing asymptomatic gliomas, preceding surgery and allowing for the initiation of prophylactic treatment. It is important to create a vast biomarker library for adults and pediatric patients due to their metabolic differences. This review focuses on the most promising proteomic, metabolomic and lipidomic glioma biomarkers, their pathways, the interactions, and correlations that can be considered characteristic of tumor grade or specific subtype.

Genomic and Transcriptomic Underpinnings of Melanoma Genesis, Progression, and Metastasis

Melanoma is a deadly skin cancer with rapidly increasing incidence worldwide. The discovery of the genetic drivers of melanomagenesis in the last decade has led the World Health Organization to reclassify melanoma subtypes by their molecular pathways rather than traditional clinical and histopathologic features. Despite this significant advance, the genomic and transcriptomic drivers of metastatic progression are less well characterized. This review describes the known molecular pathways of cutaneous and uveal melanoma progression, highlights recently identified pathways and mediators of metastasis, and touches on the influence of the tumor microenvironment on metastatic progression and treatment resistance. While targeted therapies and immune checkpoint blockade have significantly aided in the treatment of advanced disease, acquired drug resistance remains an unfortunately common problem, and there is still a great need to identify potential prognostic markers and novel therapeutic targets to aid in such cases.

Signal pathways of melanoma and targeted therapy

Melanoma is the most lethal skin cancer that originates from the malignant transformation of melanocytes. Although melanoma has long been regarded as a cancerous malignancy with few therapeutic options, increased biological understanding and unprecedented innovations in therapies targeting mutated driver genes and immune checkpoints have substantially improved the prognosis of patients. However, the low response rate and inevitable occurrence of resistance to currently available targeted therapies have posed the obstacle in the path of melanoma management to obtain further amelioration. Therefore, it is necessary to understand the mechanisms underlying melanoma pathogenesis more comprehensively, which might lead to more substantial progress in therapeutic approaches and expand clinical options for melanoma therapy. In this review, we firstly make a brief introduction to melanoma epidemiology, clinical subtypes, risk factors, and current therapies. Then, the signal pathways orchestrating melanoma pathogenesis, including genetic mutations, key transcriptional regulators, epigenetic dysregulations, metabolic reprogramming, crucial metastasis-related signals, tumor-promoting inflammatory pathways, and pro-angiogenic factors, have been systemically reviewed and discussed. Subsequently, we outline current progresses in therapies targeting mutated driver genes and immune checkpoints, as well as the mechanisms underlying the treatment resistance. Finally, the prospects and challenges in the development of melanoma therapy, especially immunotherapy and related ongoing clinical trials, are summarized and discussed.

Current concepts of ectopic nodal inclusions with special emphasis on nodal nevi

Nodal inclusions of ectopic tissue within lymph nodes are seen comparatively often in dermatopathology and general pathology. Glandular and nonglandular epithelium, as well as melanocytic nevi can be observed within lymph nodes and represent mostly incidental findings without any relevance. The main challenge in reporting these morphologic features is to differentiate such benign inclusions from metastatic settlements of distinct organ tumors. As sentinel node biopsy and lymph node dissection have become standard procedure in clinical oncology and have an immense clinical impact, the correct evaluation of these nodal inclusions is indispensable to avoid undertreatment or overtreatment of patients. In addition, the genesis of these inclusions has not yet been satisfactorily clarified. Two concepts have been laid out: the theory of benign metastases and the migration arrest theory. However, neither theory has so far been able to answer the following questions: Why do we find more nodal nevi in patients with melanoma who had a sentinel node biopsy than in patients without melanoma, and why do we not find nodal nevi in deep visceral lymph nodes? We present a comprehensive review of the current knowledge on nodal inclusions, proposing a concept for the pathogenesis of nodal nevi, to answer these questions.

Synthesis and biological evaluation of 4-phenoxy-phenyl isoxazoles as novel acetyl-CoA carboxylase inhibitors

Acetyl-CoA carboxylase (ACC) is a crucial enzyme in fatty acid metabolism, which plays a major role in the occurrence and development of certain tumours. Herein, one potential ACC inhibitor (6a) was identified through high-throughput virtual screening (HTVS), and a series of 4-phenoxy-phenyl isoxazoles were synthesised for structure-activity relationship (SAR) studies. Among these compounds, 6g exhibited the most potent ACC inhibitory activity (IC₅₀=99.8 nM), which was comparable to that of CP-640186. Moreover, the antiproliferation assay revealed that compound 6l exhibited the strongest cytotoxicity, with IC₅₀ values of 0.22 µM (A549), 0.26 µM (HepG2), and 0.21 µM (MDA-MB-231), respectively. The preliminary mechanistic studies on 6g and 6l suggested that the compounds decreased the malonyl-CoA levels, arrested the cell cycle at the G0/G1 phase, and induced apoptosis in MDA-MB-231 cells. Overall, these results indicated that the 4-phenoxy-phenyl isoxazoles are potential for further study in cancer therapeutics as ACC inhibitors.

Synthesis and in vitro evaluation of novel spiroketopyrazoles as acetyl-CoA carboxylase inhibitors and potential antitumor agents

Acetyl-CoA carboxylase (ACC) is a rate-limiting enzyme in de novo fatty acid synthesis, which plays a critical role in the growth and survival of cancer cells. In this study, a series of spiroketopyrazole derivatives bearing quinoline moieties were synthesized, and in vitro anticancer activities of these compounds as ACC inhibitors were evaluated. The biological evaluation showed that compound 7j exhibited the strongest enzyme inhibitory activity (IC₅₀ = 1.29 nM), while compound 7m displayed the most potent anti-proliferative activity against A549, HepG2, and MDA-MB-231 cells with corresponding IC₅₀ values of 0.55, 0.38, and 1.65 μM, respectively. The preliminary pharmacological studies confirmed that compound 7m reduced the intracellular malonyl-CoA and TG levels in a dose-dependent manner. Moreover, it could down-regulate cyclin D1 and CDK4 to disturb the cell cycle and up-regulate Bax, caspase-3, and PARP along with the suppression of Bcl-2 to induce apoptosis. Notably, the combination of 7m with doxorubicin synergistically decreased the HepG2 cell viability. These results indicated that compound 7m as a single agent, or in combination with other antitumor drugs, might be a promising therapeutic agent for the treatment of hepatocellular carcinoma.

The diagnostic utility of PRAME and p16 in distinguishing nodal nevi from nodal metastatic melanoma

The status of the sentinel lymph node is the strongest predictor of recurrence in patients with malignant melanoma, making accurate distinction between nodal metastases and nodal nevi of paramount importance. We explored the utility of p16 and PRAME in differentiating nodal nevi from metastatic melanoma by immunohistochemistry. We searched our institutional database for cases of nodal nevi and nodal metastatic melanoma. p16 and PRAME expression were assessed with immunolabeling quantified by extent of nuclear positivity (0-25 %, >25 %-50 %, >50 %-75 % and >75 %). Sensitivities and specificities were calculated, and discrimination assessed using the area under the receiver operating characteristic curve (AUC). Forty-nine cases out of 51 nevi and 56/56 melanoma cases had lesional tissue present for p16, while 44/51 nevi and 54/56 melanoma cases had lesional tissue present for PRAME. 43 nodal nevi (88 %) had >50 % nuclear staining for p16, while none had >50 % staining for PRAME. More than half (55 %) of melanoma cases had complete loss of nuclear staining for p16, while majority (94 %) had >50 % nuclear staining for PRAME. Using a cut-off value of 50 %, higher PRAME expression had a sensitivity and specificity of 94 % and 100 %, respectively, while lower p16 expression had a sensitivity and specificity of 66 % and 88 %, respectively, for detecting metastatic melanoma. PRAME showed significantly better discrimination (AUC = 0.97, 95 % CI 0.94-1.00) than p16 (AUC = 0.77, 95 % CI 0.68-0.86) for differentiating nodal nevi from nodal melanoma (P < 0.001). Our findings suggest that PRAME is more accurate than p16 in discriminating between the two entities, with excellent sensitivity and specificity.

Lipids in the tumor microenvironment: From cancer progression to treatment

Over the past decade, the study of metabolic abnormalities in cancer cells has risen dramatically. Cancer cells can thrive in challenging environments, be it the hypoxic and nutrient-deplete tumor microenvironment or a distant tissue following metastasis. The ways in which cancer cells utilize lipids are often influenced by the complex interactions within the tumor microenvironment and adjacent stroma. Adipocytes can be activated by cancer cells to lipolyze their triglyceride stores, delivering secreted fatty acids to cancer cells for uptake through numerous fatty acid transporters. Cancer-associated fibroblasts are also implicated in lipid secretion for cancer cell catabolism and lipid signaling leading to activation of mitogenic and migratory pathways. As these cancer-stromal interactions are exacerbated during tumor progression, fatty acids secreted into the microenvironment can impact infiltrating immune cell function and phenotype. Lipid metabolic abnormalities such as increased fatty acid oxidation and de novo lipid synthesis can provide survival advantages for the tumor to resist chemotherapeutic and radiation treatments and alleviate cellular stresses involved in the metastatic cascade. In this review, we highlight recent literature that demonstrates how lipids can shape each part of the cancer lifecycle and show that there is significant potential for therapeutic intervention surrounding lipid metabolic and signaling pathways.

Immunohistochemistry for PRAME in the Distinction of Nodal Nevi From Metastatic Melanoma

The distinction of metastatic melanoma from melanocytic nevi in lymph nodes can on occasion be difficult. As diffuse immunohistochemical (IHC) PRAME (PReferentially expressed Antigen in MElanoma) expression is detected in the majority of primary and metastatic melanomas, but rarely in nevi, we reasoned that PRAME could be a useful adjunct marker for the diagnosis of melanocytes in lymph nodes. In this study, we examined 45 nodal melanocytic deposits comprising 30 nodal nevi and 15 melanoma metastases. The latter were diagnostically not straightforward because they either coexisted with nodal nevi or were present in perinodal fibrous tissue. All nodal nevi (30/30) were negative for PRAME, whereas all melanoma metastases (15/15) were diffusely positive for PRAME IHC. We additionally report the novel use of a PRAME/Melan A dual-label immunostain. Our results show that PRAME IHC may be useful in the assessment of diagnostically challenging nodal melanocytic deposits, such as intraparenchymal nodal nevi, metastases confined to the capsular fibrous tissue, or in the setting of small metastases coexisting with a nodal nevus in the same lymph node.

Clinical significance of SLN benign capsular nevi in patients with melanoma

BACKGROUND

Benign capsular nevi (BCN) are not infrequent in sentinel lymph nodes (SLN) of patients with melanoma. Their prognostic significance is unknown and the literature is limited. This study evaluated the clinical significance of incidentally found BCN in these patients.

METHODS

A multi-institutional retrospective review of patients undergoing SLN biopsy for cutaneous melanoma between 2000 and 2016. Patients were divided into the following groups: (a) negative SLN and no BCN, (b) negative SLN and presence of BCN, (c) positive SLN seen only on immunohistochemistry (IHC), and (d) positive SLN via hematoxylin and eosin (H&E). Outcomes measured were overall survival and any recurrence.

RESULTS

A total of 1253 patients were identified (group 1 = 978, group 2 = 56, group 3 = 32, and group 4 = 187). Fifty-seven percent were male and the mean age was 59.3 years. BCN was identified in 77 patients (6.2%), of which the majority was in the node-negative group (72%). Multivariable analysis showed that BCN was associated with lower recurrence rates, though not statistically significant (hazard ratio [HR] = 0.5; P = .06). IHC- and H&E-positive SLNs were associated with a higher risk of recurrence (HR = 2.4; P = .02 and 2.0, P < .0001, respectively).

CONCLUSION

Patients with BCN and negative SLN had lower recurrence rates than patients with negative SLN and no BCN. Our data suggest a possible protective effect against recurrence.

Targeting Long Chain Acyl-CoA Synthetases for Cancer Therapy

The deregulation of cancer cell metabolic networks is now recognized as one of the hallmarks of cancer. Abnormal lipid synthesis and extracellular lipid uptake are advantageous modifications fueling the needs of uncontrolled cancer cell proliferation. Fatty acids are placed at the crossroads of anabolic and catabolic pathways, as they are implicated in the synthesis of phospholipids and triacylglycerols, or they can undergo β-oxidation. Key players to these decisions are the long-chain acyl-CoA synthetases, which are enzymes that catalyze the activation of long-chain fatty acids of 12-22 carbons. Importantly, the long-chain acyl-CoA synthetases are deregulated in many types of tumors, providing a rationale for anti-tumor therapeutic opportunities. The purpose of this review is to summarize the last up-to-date findings regarding their role in cancer, and to discuss the related emerging tumor targeting opportunities.

The role of acetyl-coA carboxylase2 in head and neck squamous cell carcinoma

Background

Acetyl-CoA carboxylase (ACC) plays an important role in the metabolism of various cancer cells, but its role in head and neck squamous cell carcinoma (HNSCC) is uncertain. Therefore, in the present study, we explored the role of ACC2 in HNSCC.

Methods

Western blot and immunohistochemistry assays were used to determine ACC2 protein expression levels in laryngocarcinoma and adjacent normal tissues derived from patients with laryngocarcinoma. ACC2 expression was knocked down in the hypopharyngeal cancer cell line FaDu to determine its effect on apoptosis. Lipid oil red staining was used to test the change of intracellular lipid.

Results

The results showed that the ACC2 protein was highly expressed in laryngocarcinoma and that the ACC2 expression level was positively associated with the clinical cancer stage and negatively associated with the degree of laryngocarcinoma cell differentiation. Kaplan-Meier analyses indicated that compared with patients having low levels of ACC2, those with high ACC2 levels had a decreased 5-year survival rate. The results of western blot and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays showed that knockdown of ACC2 accelerated apoptosis in FaDu cells. Furthermore, knockdown of ACC2 significantly reduced the intracellular lipid levels in FaDu cells.

Conclusion

These findings suggest that ACC2 may be an important prognostic marker for patients with HNSCC and that ACC2 may be a potential target in the treatment of HNSCC.

Metabolic strategies of melanoma cells: Mechanisms, interactions with the tumor microenvironment, and therapeutic implications

Melanomas are metabolically heterogeneous, and they are able to adapt in order to utilize a variety of fuels that facilitate tumor progression and metastasis. The significance of metabolism in melanoma is supported by growing evidence of impact on the efficacy of contemporary therapies for this disease. There are also data to support that the metabolic phenotypes of melanoma cells depend upon contributions from both intrinsic oncogenic pathways and extrinsic factors in the tumor microenvironment. This review summarizes current understanding of the metabolic processes that promote cutaneous melanoma tumorigenesis and progression, the regulation of cancer cell metabolism by the tumor microenvironment, and the impact of metabolic pathways on targeted and immune therapies.