Lidocaine inhibits glioma cell proliferation, migration and invasion by modulating the circEZH2/miR-181b-5p pathway

The role of lidocaine in cancer progression and patient survival

Since its development in 1943, lidocaine has been one of the most commonly used local anesthesia agents for surgical procedures. Lidocaine alters neuronal signal transmission by prolonging the inactivation of fast voltage-gated sodium channels in the cell membrane of neurons, which are responsible for action potential propagation. Recently, it has attracted attention due to emerging evidence suggesting its potential antitumor properties, particularly in the in vitro setting. Further, local administration of lidocaine around the tumor immediately prior to surgical removal has been shown to improve overall survival in breast cancer patients. However, the exact mechanisms driving these antitumor effects remain largely unclear. In this article, we will review the existing literature on the mechanism of lidocaine as a local anesthetic, its effects on the cancer cells and the tumor microenvironment, involved pathways, and cancer progression. Additionally, we will explore recent reports highlighting its impact on clinical outcomes in cancer patients. Taken together, there remains significant ambiguity surrounding lidocaine's functions and roles in cancer biology, particularly in perioperative setting.

Lidocaine attenuates TMZ resistance and inhibits cell migration by modulating the MET pathway in glioblastoma cells

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumor. Currently, the predominant clinical treatment is the combination of surgical resection with concurrent radiotherapy and chemotherapy, using temozolomide (TMZ) as the primary chemotherapy drug. Lidocaine, a widely used amide‑based local anesthetic, has been found to have a significant anticancer effect. It has been reported that aberrant hepatocyte growth factor (HGF)/mesenchymal‑epithelial transition factor (MET) signaling plays a role in the progression of brain tumors. However, it remains unclear whether lidocaine can regulate the MET pathway in GBM. In the present study, the clinical importance of the HGF/MET pathway was analyzed using bioinformatics. By establishing TMZ‑resistant cell lines, the impact of combined treatment with lidocaine and TMZ was investigated. Additionally, the effects of lidocaine on cellular function were also examined and confirmed using knockdown techniques. The current findings revealed that the HGF/MET pathway played a key role in brain cancer, and its activation in GBM was associated with increased malignancy and poorer patient outcomes. Elevated HGF levels and activation of its receptor were found to be associated with TMZ resistance in GBM cells. Lidocaine effectively suppressed the HGF/MET pathway, thereby restoring TMZ sensitivity in TMZ‑resistant cells. Furthermore, lidocaine also inhibited cell migration. Overall, these results indicated that inhibiting the HGF/MET pathway using lidocaine can enhance the sensitivity of GBM cells to TMZ and reduce cell migration, providing a potential basis for developing novel therapeutic strategies for GBM.

Trial watch: local anesthetics in cancer therapy

Preclinical evidence indicates potent antitumor properties of local anesthetics. Numerous underlying mechanisms explaining such anticancer effects have been identified, suggesting direct cytotoxic as well as indirect immunemediated effects that together reduce the proliferative, invasive and migratory potential of malignant cells. Although some retrospective and correlative studies support these findings, prospective randomized controlled trials have not yet fully confirmed the antineoplastic activity of local anesthetics, likely due to the intricate methodology required for mitigating confounding factors. This trial watch aims at compiling all published preclinical and clinical research, along with completed and ongoing trials, that explore the potential antitumor effects of local anesthetics.

circEZH2E2 /E3 is a dual suppressor of miR363/miR708 to promote EZH2 expression and prostate cancer progression

The histone methyltransferase enhancer of zeste homolog 2 (EZH2) is overexpressed in a variety of malignancies including prostate cancer (PCa) and may play important roles in tumor progression. Gene copy number gains, enhanced transcription, and a few circRNAs have been reported to upregulate EZH2. It was not known whether EZH2 itself generates circRNAs that promote its own expression. We here report the identification of circEZH2^E2/E3 that is derived from exons 2 and 3 of the EZH2 gene and overexpressed in PCa. We show that circEZH2^E2/E3 functions as a dual inhibitor for both miR363 and miR708 that target the EZH2 3'UTR and CDS, respectively, resulting in the upregulation of EZH2 expression and hence the downregulation of EZH2-repressed genes (e.g., CDH1 and DAB2IP), and enhancement of PCa cell proliferation, migration, invasion, and xenograft PCa growth. Overexpression of circEZH2^E2/E3 is significantly correlated with higher tumor grade, tumor progression, and unfavorable progression-free and disease-specific survival in PCa patients. These findings show a novel autoenhancing EZH2-circEZH2^E2/E3 -miR363/miR708-EZH2 regulatory loop, by which circEZH2^E2/E3 plays important roles in PCa tumorigenesis and progression by upregulating EZH2, and may have potential diagnostic, prognostic, and therapeutic uses in PCa management.

Impact of local anesthetics on epigenetics in cancer

Defective silencing of tumor suppressor genes through epigenetic alterations contributes to oncogenesis by perturbing cell cycle regulation, DNA repair or cell death mechanisms. Reversal of such epigenetic changes including DNA hypermethylation provides a promising anticancer strategy. Until now, the nucleoside derivatives 5-azacytidine and decitabine are the sole DNA methyltransferase (DNMT) inhibitors approved by the FDA for the treatment of specific hematological cancers. Nevertheless, due to their nucleoside structure, these inhibitors directly incorporate into DNA, which leads to severe side effects and compromises genomic stability. Much emphasis has been placed on the development of less toxic epigenetic modifiers. Recently, several preclinical studies demonstrated the potent epigenetic effects of local anesthetics, which are routinely used during primary tumor resection to relief surgical pain. These non-nucleoside molecules inhibit DNMT activity, affect the expression of micro-RNAs and repress histone acetylation, thus exerting cytotoxic effects on malignant cells. The in-depth mechanistic comprehension of these epigenetic effects might promote the use of local anesthetics as anticancer drugs.

Lidocaine represses the malignant behavior of lung carcinoma cells via the circ_PDZD8/miR-516b-5p/GOLT1A axis

Lung carcinoma is the most prevalent malignancy in adults. Lidocaine (Lido) has been confirmed to exert an anti-tumor role in many human cancers. However, the role and underlying mechanism of Lido in lung carcinoma remain poorly understood. Cell proliferation ability, migration, invasion, and apoptosis were measured by Colony formation, 5-ethynyl-2'-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), transwell, and flow cytometry assays. Circ_PDZD8, microRNA-516b-5p (miR-516b-5p), and Golgi transport 1A (GOLT1A) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Protein levels of proliferating cell nuclear antigen (PCNA) and GOLT1A were examined by western blot assay. The binding relationship between miR-516b-5p and circ_PDZD8 or GOLT1A was predicted by circular RNA Interactome or Starbase 3.0 and then verified by a dual-luciferase reporter assay. The biological roles of circ_PDZD8 and Lido on lung carcinoma cell growth were examined by the xenograft tumor model in vivo. Lido suppressed proliferation, migration, invasion, and induced apoptosis in lung carcinoma cells. Circ_PDZD8 and GOLT1A were increased, miR-516b-5p was decreased in lung carcinoma tissues and cell lines. Their expression presented the opposite trend in Lido-triggered lung carcinoma cells. Circ_PDZD8 might overturn the repression of Lido on cell growth ability and metastasis in this tumor. Mechanically, circ_PDZD8 might regulate GOLT1A expression by sponging miR-516b-5p. Circ_PDZD8 weakened the anti-lung carcinoma effect of Lido in vivo. Circ_PDZD8 might mitigate the inhibitory effect of Lido on tumor cell malignancy by modulating the miR-516b-5p/GOLT1A axis, providing a novel insight for lung carcinoma treatment.

Lidocaine represses proliferation and cisplatin resistance in cutaneous squamous cell carcinoma via miR-30c/SIRT1 regulation

This study aimed to determine the effects of lidocaine on cell proliferation and cisplatin resistance in A431 human cutaneous squamous cell carcinoma (cSCC) cells and elucidate the underlying mechanism. Cell proliferation, colony numbers, and cisplatin resistance were determined in A431 or cisplatin-resistant A431 (A431-R) cells that were first transfected with miR-30c-inhibitor or miR-30c-mimic, respectively, and then treated with different concentrations of lidocaine, cisplatin, or both. The expression levels of miR-30c and Sirtuin 1 (SIRT1) in A431 and A431-R cells were determined by quantitative real-time polymerase chain reaction and Western blotting. Lidocaine suppressed A431 cell proliferation and cisplatin resistance in a dose- and time-dependent manner via the miR-30c/SIRT1 pathway. MiR-30c overexpression also suppressed cell proliferation and cisplatin resistance in A431 cells by directly targeting and downregulating SIRT1, thus enhancing the protective effects of lidocaine. Conversely, SIRT1 upregulation or miR-30c inhibition antagonized the inhibitory effects of lidocaine. Our results suggest that lidocaine may suppress the progression of cSCC by activating the miR-30c/SIRT1 pathway, indicating its promising potential as a treatment strategy for cSCC.

Research Progress on Circular RNA in Glioma

The discovery of circular RNA (circRNA) greatly complements the traditional gene expression theory. CircRNA is a class of non-coding RNA with a stable cyclic structure. They are highly expressed, spatiotemporal-specific and conservative across species. Importantly, circRNA participates in the occurrence of many kinds of tumors and regulates the tumor development. Glioma is featured by limited therapy and grim prognosis. Cancer-associated circRNA compromises original function or creates new effects in glioma, thus contributing to oncogenesis. Therefore, this article reviews the biogenesis, metabolism, functions and properties of circRNA as a novel potential biomarker for gliomas. We elaborate the expression characteristics, interaction between circRNA and other molecules, aiming to identify new targets for early diagnosis and treatment of gliomas.

Targeting miRNAs with anesthetics in cancer: Current understanding and future perspectives

Anesthetics are extensively used during cancer surgeries. The progression of cancer can be influenced by perioperative events such as exposure to general or local anesthesia. However, whether they inhibit cancer or act as a causative factor for metastasis and exert deleterious effects on cancer growth differs based on the type of cancer and the therapy administration. Recent experimental data suggested that many of the most commonly used anesthetics in surgical oncology, whether general or local agents, can alter gene expression and cause epigenetic changes via modulating miRNAs. miRNAs are single-stranded non-coding RNAs that regulate gene expression at various levels, and their dysregulation contributes to the pathogenesis of cancers. However, anesthetics via regulating miRNAs can concurrently target several effectors of cellular signaling pathways involved in cell differentiation, proliferation, and viability. This review summarized the current research about the effects of different anesthetics in regulating cancer, with a particular emphasis on the role of miRNAs. A significant number of studies conducted in this area of research illuminate the effects of anesthetics on the regulation of miRNA expression; therefore, we hope that a thorough understanding of the underlying mechanisms involved in the regulation of miRNA in the context of anesthesia-induced cancer regulation could help to define optimal anesthetic regimens and provide better perspectives for further studies.

Perioperative pain, analgesics and cancer-related outcomes: where do we stand?

Cancer-related pain is one of the most common and debilitating symptoms among cancer patients. Undertreated cancer-related pain interferes with daily activities and increases morbidity and mortality. While opioids continue to play an essential role in treating moderate to severe cancer-related pain, they are associated with many adverse effects including misuse. While preclinical and retrospective studies have shown a negative association between opioid use and cancer outcomes, randomized control trials demonstrate that opioid use does not influence cancer recurrence. Additionally, analgesics and adjuvants used for perioperatively or chronic pain control are unlikely to improve oncological outcomes. This article focuses on the pharmacological management of cancer-related pain and offers an overview regarding the use of these medications perioperatively and the cancer outcomes.