Dexmedetomidine expands monocytic myeloid-derived suppressor cells and promotes tumour metastasis after lung cancer surgery

Effects of dexmedetomidine and ketorolac applied for patient‑controlled analgesia on the balance of Th1/Th2 and level of VEGF in patients undergoing laparoscopic surgery for cervical cancer: A randomized controlled trial

The aim of the present study was to explore the effects of dexmedetomidine (DEX) combined with ketorolac on postoperative patient-controlled analgesia (PCA), the balance of Th1/Th2 and the level of vascular endothelial growth factor (VEGF) in patients with cervical cancer following laparoscopic radical surgery. A total of 70 women with cervical cancer undergoing laparoscopic radical hysterectomy were enrolled in the study to randomly receive postoperative dexmedetomidine combined with ketorolac analgesia (DK group) and postoperative sufentanil analgesia (SUF group). The primary outcomes were the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and VEGF, and the IFN-γ/IL-4 ratio 30 min before induction (T0), and 24 and 48 h after surgery. Secondary outcomes included numerical rating scale scores at 0 h (T0), 4 h (T1), 12 h (T2), 24 h (T3) and 48 h (T4) postoperatively, cumulative times of rescue analgesia, as well as the incidence of postoperative side effects within 48 h from surgery. Patients in the DK group reported similar analgesic effects as patients in the SUF group at T2, T3 and T4, and the incidence of postoperative nausea and vomiting was significantly lower in the DK group. In the DK group, the serum concentration of IFN-γ and IFN-γ/IL-4 ratio at 24 and 48 h after surgery were higher compared with those in the SUF group. Conversely, the serum concentrations of IL-4 at 24 h after surgery and VEGF at 24 and 48 h after surgery were significantly lower. The results indicated that the combination of DEX and ketorolac for PCA significantly improved postoperative pain and decreased the serum level of VEGF, which are associated with tumor angiogenesis. In addition, it maintained the homeostasis of postoperative immune dysfunction of patients with cervical cancer by shifting the balance between type 1 T helper cells and type 2 T helper cell (Th1/Th2 balance) to Th1 (registration no. ChiCTR1900027979; December 7, 2019).

Interactions between MDSCs and the Autonomic Nervous System: Opportunities and Challenges in Cancer Neuroscience

Myeloid-derived suppressor cells (MDSC) are a population of heterogeneous immune cells that are involved in precancerous conditions and neoplasms. The autonomic nervous system (ANS), which is composed of the sympathetic nervous system and the parasympathetic nervous system, is an important component of the tumor microenvironment that responds to changes in the internal and external environment mainly through adrenergic and cholinergic signaling. An abnormal increase of autonomic nerve density has been associated with cancer progression. As we discuss in this review, growing evidence indicates that sympathetic and parasympathetic signals directly affect the expansion, mobilization, and redistribution of MDSCs. Dysregulated autonomic signaling recruits MDSCs to form an immunosuppressive microenvironment in chronically inflamed tissues, resulting in abnormal proliferation and differentiation of adult stem cells. The two components of the ANS may also be responsible for the seemingly contradictory behaviors of MDSCs. Elucidating the underlying mechanisms has the potential to provide more insights into the complex roles of MDSCs in tumor development and lay the foundation for the development of novel MDSC-targeted anticancer strategies.

Anesthesia and cancer recurrence: a narrative review

Cancer is a leading cause of death worldwide. With the increasingly aging population, the number of emerging cancer cases is expected to increase markedly in the foreseeable future. Surgical resection with adjuvant therapy is the best available option for the potential cure of many solid tumors; thus, approximately 80% of patients with cancer undergo at least one surgical procedure during their disease. Agents used in general anesthesia can modulate cytokine release, transcription factors, and/or oncogenes. This can affect host immunity and the capability of cancer cells to survive and migrate, not only during surgery but for up to several weeks after surgery. However, it remains unknown whether exposure to anesthetic agents affects cancer recurrence or metastasis. This review explores the current literature to explain whether and how the choice of anesthetic and perioperative medication affect cancer surgery outcomes.

Trial watch: dexmedetomidine in cancer therapy

Dexmedetomidine (DEX) is a highly selective α2-adrenoceptor agonist that is widely used in intensive and anesthetic care for its sedative and anxiolytic properties. DEX has the capacity to alleviate inflammatory pain while limiting immunosuppressive glucocorticoid stress during major surgery, thus harboring therapeutic benefits for oncological procedures. Recently, the molecular mechanisms of DEX-mediated anticancer effects have been partially deciphered. Together with additional preclinical data, these mechanistic insights support the hypothesis that DEX-induced therapeutic benefits are mediated via the stimulation of adaptive anti-tumor immune responses. Similarly, published clinical trials including ancillary studies described an immunostimulatory role of DEX during the perioperative period of cancer surgery. The impact of DEX on long-term patient survival remains elusive. Nevertheless, DEX-mediated immunostimulation offers an interesting therapeutic option for onco-anesthesia. Our present review comprehensively summarizes data from preclinical and clinical studies as well as from ongoing trials with a distinct focus on the role of DEX in overcoming (tumor microenvironment (TME)-imposed) cancer therapy resistance. The objective of this update is to guide clinicians in their choice toward immunostimulatory onco-anesthetic agents that have the capacity to improve disease outcome.

Niche Roles for Dexmedetomidine in the Intensive Care Unit

OBJECTIVE

Review dexmedetomidine use in critically ill patients for niche indications including sleep, delirium, alcohol withdrawal, sepsis, and immunomodulation.

DATA SOURCES

Literature was sought using PubMed (February 2012-November 2022). Search terms included dexmedetomidine AND (hypnotics OR sedatives OR sleep OR delirium OR immunomodulation OR sepsis OR alcohol withdrawal).

STUDY SELECTION AND DATA EXTRACTION

Relevant studies conducted in humans ≥18 years published in English were included. Exclusion criteria included systematic reviews, meta-analyses, and studies evaluating oral dexmedetomidine or other alpha-2 agonists.

DATA SYNTHESIS

A total of 231 articles were retrieved. After removal of duplicates, title and abstract screening, and application of inclusion criteria, 35 articles were included. Across the clinical conditions included in this review, varying clinical outcomes were seen. Dexmedetomidine may improve morbidity outcomes in delirium, sleep, and alcohol withdrawal syndrome. Due to limited human studies and poor quality of evidence, no conclusions can be drawn regarding the role of dexmedetomidine in immunomodulation or sepsis.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review presents data for potential niche roles of dexmedetomidine aside from sedation in critically ill patients. This may serve as a guide for sedation selection in critically ill patients who may also benefit from the pleiotropic effects of dexmedetomidine due to a clinical condition discussed in this review.

CONCLUSION

While further studies are needed, dexmedetomidine may provide benefit in other indications in critically ill patients including delirium, sleep, and alcohol withdrawal. Given the poor quality of evidence of dexmedetomidine use in immunomodulation and sepsis, no conclusions can be drawn.

Association between intraoperative dexmedetomidine and all-cause mortality and recurrence after laparoscopic resection of colorectal cancer: Follow-up analysis of a previous randomized controlled trial

Background

Dexmedetomidine (DEX) has been widely applied in the anesthesia and sedation of patients with oncological diseases. However, the potential effect of DEX on tumor metastasis remains contradictory. This study follows up on patients who received intraoperative DEX during laparoscopic resection of colorectal cancer as part of a previous clinical trial, examining their outcomes 5 years later.

Methods

Between June 2015 and December 2015, 60 patients undergoing laparoscopic colorectal resection were randomly assigned to the DEX and control groups. The DEX group received an initial loading dose of 1μ/kg before surgery, followed by a continuous infusion of 0.3μg/kg/h during the operation and the Control group received an equivalent volume of saline. A 5-year follow-up analysis was conducted to evaluate the overall survival, disease-free survival, and tumor recurrence.

Results

The follow-up analysis included 55 of the 60 patients. The DEX group included 28 patients, while the control group included 27 patients. Baseline characteristics were comparable between the two groups, except for vascular and/or neural invasion of the tumor in the DEX group (9/28 vs. 0/27, p = 0.002). We did not observe a statistically significant benefit but rather a trend toward an increase in overall survival and disease-free survival in the DEX group, 1-year overall survival (96.4% vs. 88.9%, p = 0.282), 2-year overall survival (89.3% vs. 74.1%, p = 0.144), 3-year overall survival (89.3% vs. 70.4%, p = 0.08), and 5-year overall survival (78.6% vs. 59.3%, p = 0.121). The total rates of mortality and recurrence between the two groups were comparable (8/28 vs. 11/27, p = 0.343).

Conclusion

Administration of DEX during laparoscopic resection of colorectal cancer had a nonsignificant trend toward improved overall survival and disease-free survival.

Clinical Trial Registration

http://www.chictr.org.cn/, identifier ChiCTRIOR-15006518.

Dexmedetomidine provides type-specific tumour suppression without tumour-enhancing effects in syngeneic murine models

BACKGROUND

Dexmedetomidine is a widely used anaesthetic adjuvant for cancer resection surgeries. However, recent reports suggest that it may promote tumour growth or metastasis, so it is essential to clarify its tumour-related effects.

METHODS

Seven syngeneic murine tumour models were used to assess the impact of dexmedetomidine on primary tumour growth, spontaneous tumour metastasis, and surgical resection-associated metastasis. Cancer cell proliferation and apoptosis experiments, terminal deoxynucleotidyl transferase dUTP nick-end labelling assays, immune cell analysis, specific T-cell depletion experiments, and gene transcription analysis were conducted to identify the underlying mechanisms.

RESULTS

Dexmedetomidine did not affect growth of EO771 or 4T1 breast tumours, LAP0297 or LLC lung tumours, MCA205 fibrosarcoma, or their spontaneous lung metastases. It did not promote lung metastasis after breast cancer resection. Dexmedetomidine significantly suppressed MCA38 and CT26 colorectal tumour growth (P<0.01) and promoted apoptosis in MCA38 tumour tissues (P<0.05) without affecting proliferation and apoptosis of MCA38 tumour cells in vitro, suggesting indirect anti-tumour effects. Dexmedetomidine increased the proportions of intratumour CD4⁺ T (P<0.01), CD8⁺ T (P<0.001), and natural killer cells (P<0.01), and it upregulated transcription of the cytotoxicity-related genes Infg, Tnfa, and Cxcl9 (P<0.05) in MCA38 tumours. Either CD8⁺ or CD4⁺ T-cell depletion reversed the anti-tumour effects of dexmedetomidine on MCA38 tumours (P<0.05).

CONCLUSIONS

Dexmedetomidine conferred colorectal tumour-type specific suppression by modulation of tumour CD4⁺ and CD8⁺ T cells without tumour-enhancing effects.

LncRNAs has been identified as regulators of Myeloid-derived suppressor cells in lung cancer

Lung tumours are widespread pathological conditions that attract much attention due to their high incidence of death. The immune system contributes to the progression of these diseases, especially non-small cell lung cancer, resulting in the fast evolution of immune-targeted therapy. Myeloid-derived suppressor cells (MDSCs) have been suggested to promote the progression of cancer in the lungs by suppressing the immune response through various mechanisms. Herein, we summarized the clinical studies on lung cancer related to MDSCs. However, it is noteworthy to mention the discovery of long non-coding RNAs (lncRNAs) that had different phenotypes and could regulate MDSCs in lung cancer. Therefore, by reviewing the different phenotypes of lncRNAs and their regulation on MDSCs, we summarized the lncRNAs' impact on the progression of lung tumours. Data highlight LncRNAs as anti-cancer agents. Hence, we aim to discuss their possibilities to inhibit tumour growth and trigger the development of immunosuppressive factors such as MDSCs in lung cancer through the regulation of lncRNAs. The ultimate purpose is to propose novel and efficient therapy methods for curing patients with lung tumours.

Efficacy and safety evaluation of dexmedetomidine for postoperative patient controlled intravenous analgesia: A systematic review and meta-analysis

Objective: To investigate the efficacy and safety of dexmedetomidine (DEX) for postoperative patient controlled intravenous analgesia (PCIA). Measurements: Two investigators independently searched Pubmed, Embase, Scopus, Cochrane Library and CBM for randomized controlled trials of DEX for PCIA. Main results: Thirty-seven studies with a total of 5,409 patients were included in this meta-analysis. Compared with analgesics alone, DEX for PCIA reduced pain score at 24 h [mean difference (MD) = -0.70; 95% confidence interval (CI): -0.85, -0.54; p < 0.00001, I ² = 90%] and 48 h postoperatively (MD = -0.43; 95% CI: -0.52, -0.34; p < 0.00001, I ² = 96%). Moreover, DEX reduced analgesics consumption during the first 24 h [standardized mean difference (SMD) = -0.25; 95% CI: -0.34, -0.16; p < 0.00001, I ² = 91%] and the number of resuscitation analgesics administered [odds ratio (OR) = 0.54; 95% CI: 0.44, 0.66; p < 0.00001, I ² = 72%]. Furthermore, DEX improved patient satisfaction (OR = 3.55; 95% CI: 2.36, 5.35; p < 0.00001, I ² = 60%), and reduced incidence of side effects, such as postoperative nausea and vomiting (PONV) (OR = 0.47; 95% CI: 0.39, 0.57; p < 0.00001, I ² = 59%) and pruritus after surgery (OR = 0.45; 95% CI: 0.30, 0.68; p = 0.0001, I ² = 0%). Besides, DEX attenuates inflammatory cytokine levels, such as IL-6 (MD = -5.73; 95% CI: -8.34, -3.12; p < 0.00001, I ² = 91%) and TNF-α (MD = -0.63; 95% CI: -0.76, -0.50; p < 0.00001, I ² = 89%). Finally, DEX increased the risk of bradycardia (OR = 1.66; 95% CI: 1.12, 2.45; p = 0.01, I ² = 15%), but the complication of hypotension did not differ between the two groups (OR = 1.30; 95% CI: 0.84, 2.04; p = 0.25, I ² = 0%). Conclusion: DEX is used for postoperative PCIA analgesia, which can significantly improve the analgesic effect, effectively control postoperative inflammatory response, reduce the dosage and adverse reactions of analgesics, and improve postoperative patient satisfaction. Of course, the impact of the immunosuppressive effect of DEX on the prognosis of patients needs further study. Systematic review registration: CRD42022340933, https://www.crd.york.ac.uk/prospero/.

Perioperative Inflammatory Response and Cancer Recurrence in Lung Cancer Surgery: A Narrative Review

While surgical resection is the gold standard treatment for solid tumors, cancer recurrence after surgery is common. Immunosurveillance of remnant tumor cells is an important protective mechanism. Therefore, maintenance of anti-tumor cell activity and proper levels of inflammatory mediators is crucial. An increasing body of evidence suggests that surgery itself and perioperative interventions could affect these pathophysiological responses. Various factors, such as the extent of tissue injury, perioperative medications such as anesthetics and analgesics, and perioperative management including transfusions and methods of mechanical ventilation, modulate the inflammatory response in lung cancer surgery. This narrative review summarizes the pathophysiological mechanisms involved in cancer recurrence after surgery and perioperative management related to cancer recurrence after lung cancer surgery.

Application Effect of Dexmedetomidine and Dezocine in Patients Undergoing Lung Cancer Surgery under General Anesthesia and Analysis of Their Roles in Recovery Time and Cognitive Function

Objective. To explore the application influence of dexmedetomidine (DEX) and dezocine in patients undergoing lung cancer surgery under general anesthesia and analysis of their roles in recovery time and cognitive function. Methods. A total of 120 patients who accepted thoracoscopic pulmonary wedge resection in our hospital from November 2021 to April 2022 were selected and randomly divided into group A ( $n$  =60) and group B ( $n$  =60). DEX combined with dezocine-assisted anesthesia was performed to group A, and the equal dose of normal saline was administered to group B, so as to compare their inflammatory influence level, brain function, arterial blood gas index, and cognitive function. Results. Compared with group B, group A obtained significantly lower intraoperative and postoperative inflammatory factor levels ( $P<0.001$ ), better postoperative brain function and arterial blood gas index ( $P<0.001$ ), and lower Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) scores after surgery ( $P<0.001$ ). Combining DEX with dezocine-assisted general anesthesia can improve the inflammatory factors level of patients undergoing lung cancer surgery and maintain their brain function and oxygen saturation, so that they have better postoperative cognitive function. Therefore, such anesthesia modality should be promoted in practice.

Anesthesia and Oncology: Friend or Foe?

Cancer is a leading cause of death, and surgery is an important treatment modality. Laboratory research and retrospective studies have raised the suspicion that the choice of anesthetics for cancer surgery might affect the course of cancerous disease. The aim of this review is to provide a critical overview of the current state of knowledge. Inhalational anesthesia with volatiles or total intravenous anesthesia (TIVA) with propofol are the two most commonly used anesthetic techniques. Most data comparing volatile anesthetics with TIVA is from either in vitro or retrospective studies. Although conflicting, data shows a trend towards favoring propofol. Opioids are commonly used in anesthesia. Data on potential effects of opioids on growth and recurrence of cancer are scarce and conflicting. Preclinical studies have shown that opioids stimulate cancer growth through the µ-opioid receptor. Opioids also act as immunosuppressants and, therefore, have the potential to facilitate metastatic spread. However, the finding of an adverse effect of opioids on tumor growth and cancer recurrence by some retrospective studies has not been confirmed by prospective studies. Regional anesthesia has not been found to have a beneficial effect on the outcome of surgically treated cancer patients, but prospective studies are scarce. Local anesthetics might have a beneficial effect, as observed in animal and in vitro studies. However, prospective clinical studies strongly question such an effect. Blood products, which may be needed during extensive cancer surgery suppress the immune system, and data strongly suggest a negative impact on cancer recurrence. The potential effects of other commonly used anesthetic agents on the outcome of cancer patients have not been sufficiently studied for drawing valid conclusions. In conclusion, laboratory data and most retrospective studies suggest a potential advantage of TIVA over inhalational anesthesia on the outcome of surgical cancer patients, but prospective, randomized studies are missing. Given the state of weak scientific evidence, TIVA may be used as the preferred type of anesthesia unless there is an individual contraindication against it. Studies on the effects of other drugs frequently used in anesthesia are limited in number and quality, and have found conflicting results.

Anesthesia and Cancer, Friend or Foe? A Narrative Review

Cancer remains the leading cause of death worldwide with close to 10 million deaths reported annually. Due to growth of the advanced age cohort in our population, it is predicted that the number of new cancer cases diagnosed between now until 2035 is to reach potentially 24 million individuals, a staggering increase in a relatively short time period. For many solid tumors, surgical resection along with chemotherapy is the best available approach to a potential cure which leads to almost 80% of cancer patients undergoing at least one surgical procedure during the course of their disease. During surgical intervention, the exposure to general anesthesia can be lengthy, complex and often involves various modalities resulting in an important question as to the role, if any, anesthesia may play in primary recurrence or metastatic conversion. Many components of the stress and inflammatory responses exhibited in the perioperative period can contribute to cancer growth and invasion. The agents used to induce and maintain general anesthesia have variable interactions with the immune and neuroendocrine systems and can influence the stress response during surgery. Thus, debating the best type of anesthesia that would help to attenuate sympathetic and/or pro-inflammatory responses while modulating cytokine release and transcription factors/oncogenes remains at the forefront. This may affect inducible cancer cell survival and migratory abilities not only intra-operatively, but also during the immediate post-operative phase of recovery. The ultimate question becomes how and whether the choice of anesthesia may influence the outcomes of cancer surgery with two major approaches being considered, i.e., regional and general anesthesia as well as the various hypnotics, analgesics and sympatholytics commonly used. In this review, we will address the latest information as to the role that anesthesia may play during cancer surgery with specific focus on primary recurrence and metastasis.

Can Acute Postoperative Pain Management After Tumour Resection Surgery Modulate Risk of Later Recurrence or Metastasis?

Background

Cancer is a leading cause of mortality worldwide, but death is rarely from the primary tumour: Rather it is multi-organ dysfunction from metastatic disease that is responsible for up to 90% of cancer-related deaths. Surgical resection of the primary tumour is indicated in 70% of cases. The perioperative stress response, tissue hypoxia at the site of surgery, and acute pain contribute to immunosuppression and neo-angiogenesis, potentially promoting tumour survival, proliferation, and metastasis. Poorly controlled acute postoperative pain decreases Natural Killer (NK) immune cell activity, which could potentially facilitate circulating tumour cells from evading immune detection. This consequently promotes tumour growth and distal metastasis.

Methods

We conducted a comprehensive literature search for links between acute pain and cancer outcomes using multiple online databases. Relevant articles from January 1st, 2010 to September 1st, 2021 were analysed and appraised on whether postoperative pain control can modulate the risk of recurrence, metastasis, and overall cancer survival.

Results

Although experimental and retrospective clinical data suggest a plausible role for regional anaesthesia in cancer outcome modulation, this has not been supported by the single, largest prospective trial to date concerning breast cancer. While there are mixed results on anaesthesiology drug-related interventions, the most plausible data relates to total intravenous anaesthesia with propofol, and to systemic administration of lidocaine.

Conclusion

The hypothesis that anaesthetic and analgesic technique during cancer surgery could influence risk of subsequent recurrence or metastasis has been prevalent for >15 years. The first, large-scale definitive trial among women with breast cancer found robust equivalent findings between volatile anaesthesia with opioid analgesia and regional anaesthesia. Therefore, while regional anaesthesia during tumour resection does not seem to have any effect on cancer outcomes, it remains plausible that other anaesthetic techniques (e.g. total intravenous anaesthesia and systemic lidocaine infusion) might influence oncologic outcome in other major tumour resection surgery (e.g. colorectal and lung). Therefore, another large trial is needed to definitively answer these specific research questions. Until such evidence is available, perioperative analgesia for cancer surgery of curative intent should be based on patient co-morbidity and non-cancer endpoints, such as optimising analgesia and minimising postoperative complications.

Effects of Anesthesia and Anesthetic Techniques on Metastasis of Lung Cancers: A Narrative Review

Purpose

Tumor recurrence and metastasis are essential for the mortality and morbidity of cancer. Surgical resection of solid tumors is the conventional treatment approach for malignant tumors. However, even after undergoing radical surgery, certain patients develop local or distant metastasis, which may contribute to treatment failure. Anesthesia and anesthetic techniques are widely used in the perioperative period. Emerging evidence indicates that anesthetics influence tumor recurrence and metastasis. Therefore, the current review summarizes the effects of anesthesia and anesthetic techniques on tumor recurrence and lung metastasis.

Methods

Relevant literature was retrieved from the following databases: Medline/PubMed, CNKI and Wanfang. A total of 109 articles were selected and analyzed in this research.

Results

(1) A variety of intravenous anesthetics may affect metastasis or tumor growth, though the evidence is contradictory and inconsistent, and the clinical data are still inconclusive. (2) Volatile anesthetics have proinflammatory effects and may have direct and indirect effects on the survival of cancer cells. (3) Although the relevant clinical data are limited, there is strong evidence in vitro that local anesthetics have a protective effect on cancer recurrence. (4) No mode of anesthesia has been determined to be beneficial to patients with cancer, but clinical studies are currently recommended for anesthesia modality and composite use.

Conclusion

Available data suggest that anesthesia and anesthetic techniques might play an important role in tumor progression and lung metastasis, the understanding of which will help in designing more effective management of the tumor and attaining fewer side effects.

Effect of Dexmedetomidine on Biochemical Recurrence in Patients after Robot-Assisted Laparoscopic Radical Prostatectomy: A Retrospective Study

The usage of dexmedetomidine during cancer surgery in current clinical practice is debatable, largely owing to the differing reports of its efficacy based on cancer type. This study aimed to investigate the effects of dexmedetomidine on biochemical recurrence (BCR) and radiographic progression in patients with prostate cancer, who have undergone robot-assisted laparoscopic radical prostatectomy (RALP). Using follow-up data from two prospective randomized controlled studies, BCR and radiographic progression were compared between individuals who received dexmedetomidine (n = 58) and those who received saline (n = 56). Patients with complete follow-up records between July 2013 and June 2019 were enrolled in this study. There were no significant between-group differences in the number of patients who developed BCR and those who showed positive radiographic progression. Based on the Cox regression analysis, age (p = 0.015), Gleason score ≥ 8 (p < 0.001), and pathological tumor stage 3a and 3b (both p < 0.001) were shown to be significant predictors of post-RALP BCR. However, there was no impact on the dexmedetomidine or control groups. Low-dose administration of dexmedetomidine at a rate of 0.3–0.4 μg/kg/h did not significantly affect BCR incidence following RALP. In addition, no beneficial effect was noted on radiographic progression.

Dexmedetomidine upregulates the expression of miR-493-5p, inhibiting growth and inducing the apoptosis of lung adenocarcinoma cells by targeting RASL11B

Numerous studies have indicated that microRNAs (miRNAs) play critical roles in the development and progression of cancer. However, how changes to the expression levels of miRNAs in response to dexmedetomidine affects the progression of lung cancer remains poorly understood. In this study, we treated the lung adenocarcinoma cell line-A549 with dexmedetomidine and then examined the changes to the expression levels of miRNAs. We found that one of the most significantly upregulated miRNAs was miR-493-5p, which has an important role in the growth and apoptosis of lung adenocarcinoma (LUAD) cells. In addition, bioinformatics searches and luciferase reporter assays revealed that miR-493-5p targets RASL11B, which has a high degree of similarity to RAS. Finally, database searches revealed that RASL11B is associated with survival of LUAD cells. In conclusion, dexmedetomidine causes changes to the expression levels of miRNAs in LUAD, including significant upregulation of miR-493-5p. MiR-493-5p targets RASL11B, thereby inhibiting cell growth and inducing apoptosis in LUAD.

Dexmedetomidine Inhibited Proliferation and Invasion of Cervical Cancer Cells by Inhibiting the Janus Tyrosine Kinase/Signal Transducer and Activator of Transcription Signaling Pathway

The role of anesthetics in the treatment of cancer has been reported, but the role of Dexmedetomidine (Dex) in the treatment of cervical cancer (CC) has not been reported.In this study, cell viability and proliferation were determined by MTT and cloning formation assay. The expression of proliferation-related proteins ki67 and PCNA was detected by western blot. Wound healing and transwell detected cell migration and invasion, and western blot detected the expression of migration and invasion related proteins MMP4 and MMP9, and epithelial-mesenchymal transformation (ETM)-related proteins N-cadherin, Snail, Vimentin and E-cadherin. Western blot also detected the expression of pathway related proteins p-JAK2, p-STAT1, p-STAT3, JAK2, STAT1 and STAT3. It showed that Dex inhibited the cell viability and proliferation of Hela and siHa and the expression of ki67 and PCNA were also inhibited. Dex inhibited the cell migration and invasion, and inhibited the expression of MMP4 and MMP9. In addition, Dex inhibited the expression of N-cadherin, Snail and Vimentin, and promoted the expression of E-cadherin. Dex inhibited the expression of p-JAK2, p-STAT1 and p-STAT3. After the addition of JAK/STAT signaling pathway agonist IL-6, the inhibition of Dex on proliferation, migration and invasion of CC cells was reversed. And the addition of JAK/STAT signaling pathway inhibitor AG490 could counteract the excitatory effect of IL-6 on the pathway, at which time the cell proliferation, invasion and migration were significantly increased. In conclusion, our study demonstrated that Dex inhibited proliferation, migration, and invasion of cells in CC by blocking the JAK/STAT signaling pathway.

Targeting Myeloid-Derived Suppressor Cells for Premetastatic Niche Disruption After Tumor Resection

Surgical resection is a common therapeutic option for primary solid tumors. However, high cancer recurrence and metastatic rates after resection are the main cause of cancer related mortalities. This implies the existence of a "fertile soil" following surgery that facilitates colonization by circulating cancer cells. Myeloid-derived suppressor cells (MDSCs) are essential for premetastatic niche formation, and may persist in distant organs for up to 2 weeks after surgery. These postsurgical persistent lung MDSCs exhibit stronger immunosuppression compared with presurgical MDSCs, suggesting that surgery enhances MDSC function. Surgical stress and trauma trigger the secretion of systemic inflammatory cytokines, which enhance MDSC mobilization and proliferation. Additionally, damage associated molecular patterns (DAMPs) directly activate MDSCs through pattern recognition receptor-mediated signals. Surgery also increases vascular permeability, induces an increase in lysyl oxidase and extracellular matrix remodeling in lungs, that enhances MDSC mobilization. Postsurgical therapies that inhibit the induction of premetastatic niches by MDSCs promote the long-term survival of patients. Cyclooxygenase-2 inhibitors and β-blockade, or their combination, may minimize the impact of surgical stress on MDSCs. Anti-DAMPs and associated inflammatory signaling inhibitors also are potential therapies. Existing therapies under tumor-bearing conditions, such as MDSCs depletion with low-dose chemotherapy or tyrosine kinase inhibitors, MDSCs differentiation using all-trans retinoic acid, and STAT3 inhibition merit clinical evaluation during the perioperative period. In addition, combining low-dose epigenetic drugs with chemokine receptors, reversing immunosuppression through the Enhanced Recovery After Surgery protocol, repairing vascular leakage, or inhibiting extracellular matrix remodeling also may enhance the long-term survival of curative resection patients.

Exploiting a New Approach to Destroy the Barrier of Tumor Microenvironment: Nano-Architecture Delivery Systems

Recent findings suggest that tumor microenvironment (TME) plays an important regulatory role in the occurrence, proliferation, and metastasis of tumors. Different from normal tissue, the condition around tumor significantly altered, including immune infiltration, compact extracellular matrix, new vasculatures, abundant enzyme, acidic pH value, and hypoxia. Increasingly, researchers focused on targeting TME to prevent tumor development and metastasis. With the development of nanotechnology and the deep research on the tumor environment, stimulation-responsive intelligent nanostructures designed based on TME have attracted much attention in the anti-tumor drug delivery system. TME-targeted nano therapeutics can regulate the distribution of drugs in the body, specifically increase the concentration of drugs in the tumor site, so as to enhance the efficacy and reduce adverse reactions, can utilize particular conditions of TME to improve the effect of tumor therapy. This paper summarizes the major components and characteristics of TME, discusses the principles and strategies of relevant nano-architectures targeting TME for the treatment and diagnosis systematically.

Influence of anaesthetics on the production of cancer cell motogens, stromal cell-derived factor-1 and hepatocyte growth factor by fibroblasts

Anaesthetics have been implicated to influence cancer cells and progression. Similarly, crosstalk between cancer cells and stromal components within the microenvironment is also an important factor driving progression. Stromal cell-derived factor-1 (SDF-1) and hepatocyte growth factor (HGF) are key chemokines/cytokines produced by fibroblasts which have been established as influential factors in cancer progression. The present study explored the capacity of anaesthetics to influence the expression of these key molecules in fibroblasts. The anaesthetics rocuronium bromide (RB), vecuronium bromide (VB), suxamethonium chloride CRS (SCC), dexmedetomidine hydrochloride (DH) and lidocaine were used to treat MRC-5 fibroblasts over a range of concentrations. Following treatment, transcript expression of SDF-1 and HGF was quantified using quantitative PCR. Treatment of MRC-5 cells with RB brought about a reduction of SDF-1 expression which was found to be significant in the 45 µg/ml treatment group. Treatment with the other anaesthetics brought about some alterations in SDF-1 expression but these were not found to be statistically significant. Treatment with the tested anaesthetics did not have any significant effect on HGF transcript expression within MRC-5 cells, although again some alterations were observed. The results indicated that anaesthetics may have an impact on the fibroblast component of the tumour microenvironment, potentially influencing SDF-1 and HGF expression which in turn could influence tumour progression.

Activation of PI3K/Akt/HIF-1α Signaling is Involved in Lung Protection of Dexmedetomidine in Patients Undergoing Video-Assisted Thoracoscopic Surgery: A Pilot Study

Background

Lung resection and one lung ventilation (OLV) during video-assisted thoracoscopic surgery (VATS) may lead to acute lung injury. Dexmedetomidine (DEX), a highly selective α₂ adrenergic receptor agonist, improves arterial oxygenation in adult patients undergoing thoracic surgery. The aim of this pilot study was to explore possible mechanism related to lung protection of DEX in patients undergoing VATS.

Patients and Methods

Seventy-four patients scheduled for VATS were enrolled in this study. Three timepoints (before anesthesia induction (T₀), 40 min after OLV (T₁), and 10 min after two-lung ventilation (T₂)) of arterial blood gas were obtained. Meanwhile, lung histopathologic examination, immunohistochemistry analysis (occludin and ZO-1), levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in lung tissue and plasma, and activation of phosphoinositide-3-kinase (PI3K)/AKT/hypoxia-inducible factor (HIF)-1α signaling were detected. Postoperative outcomes including duration of withdrawing the pleural drainage tube, length of hospital stay, hospitalization expenses, and postoperative pulmonary complications (PPCs) were also recorded.

Results

Sixty-seven patients were randomly divided into DEX group (group D, n=33) and control group (group N, n=34). DEX improved oxygenation at T₁ and T₂ (group D vs group N; T₁: 191.8 ± 49.8 mmHg vs 159.6 ± 48.1 mmHg, P = 0.009; T₂: 406.0 mmHg [392.2–423.7] vs 374.5 mmHg [340.2–378.2], P = 0.001). DEX alleviated the alveolar capillary epithelial structure damage, increased protein expression of ZO-1 and occludin, inhibited elevation of the expression of TNF-α and IL-6 in lung tissue and plasma, and increased protein expression of p-PI3K, p-AKT and HIF-1α. Dex administered had better postoperative outcomes with less risk of PPCs and hospitalization expenses as well as shorter duration of withdrawing the pleural drainage tube and length of hospital stay.

Conclusion

Activation of PI3K/Akt/HIF-1α signaling might be involved in lung protection of DEX in patients undergoing VATS.

The outcomes of dexmedetomidine and calcitriol on flap viability

Purpose:

To evaluate protective effects of dexmedetomidine, calcitriol and their combination.

Methods:

Forty Wistar-albino rats were divided into 4 groups; group of Sham (Group Sham); group of dexmedetomidine (Group DEX); group of calcitriol (Group CAL) and group of dexmedetomidineandcalcitriol (Group DEX-CAL). Photographic analysis was used for macroscopic analysis and perfusion analyses were evaluated by scintigraphy. Additionally, tissue malondialdehyde (MDA) and total oxidant status (TOS) and total antioxidant activity (TAS) were recorded and oxidative stress index (OSI) was calculated. Each flap was assessed by histopathology.

Results:

Compared to Group Sham, the viable flap areas were higher in all treatment groups both by photographic image analyses and perfusion analyses (p<0.05). Group DEX-CAL had the highest viable flap percentage both in scintigraphic and photographic analyses; whereas Group Sham had the lowest viable flap percentage. Similarly, TAS and MDA levels were elevated and TOS levels were declined in all treatment groups compared to Group Sham (p<0.005). Histopathological analysis at flap demarcation zone confirmed neovascularization was significantly higher and edema, necrosis and inflammation were significantly lower in all treatment groups compared to Group Sham.

Conclusion:

The outcomes show that additional premedication with either dexmedetomidine or calcitriol or their combination reduces ischemia-reperfusion injury of flap area and show significant increase in the percentage of viable flap tissue.

Thymosin alpha-1 blocks the accumulation of myeloid suppressor cells in NSCLC by inhibiting VEGF production

BACKGROUND

Thymosin alpha-1 (TA) has been reported to inhibit tumor growth as an immunomodulator. However, its mechanism of action in immunosuppressive cells is unclear. The purpose of this study was to investigate whether TA can reshape the immune microenvironment by inhibiting the function of myeloid-derived suppressor cells (MDSCs) in non-small cell lung carcinoma (NSCLC).

METHODS

The effects of TA on peripheral blood monocytic MDSCs (M-MDSCs) in patients with NSCLC and on the apoptosis and migration of M-MDSCs were studied. A mouse subcutaneous xenograft tumor model was constructed, and the effect of TA on M-MDSC migration was evaluated. Quantitative real-time PCR, Western blotting, flow cytometry and immunohistochemistry were used to examine the mechanism by which TA affects M-MDSCs.

RESULTS

TA not only promoted the apoptosis of M-MDSCs by reducing the Bcl-2/BAX ratio but also and more importantly inhibited the migration of MDSCs to the tumor microenvironment by suppressing the production of vascular endothelial growth factor (VEGF) through the downregulation of hypoxia-inducible factor (HIF)-1α in tumor cells.

CONCLUSIONS

TA may have a novel antitumor effect mediated by decreasing M-MDSC accumulation in the tumor microenvironment through reduced VEGF production.

Dexmedetomidine in cancer surgeries: Present status and consequences with its use

Dexmedetomidine is a centrally acting α2 adrenoreceptor agonist used in perioperative medicine due to its sedative, analgesic and sympatholytic properties. Recently animal data has pointed towards potential role of dexmedetomidine in promoting cancer recurrence and metastasis when used perioperatively especially after breast surgeries. This is because of presence of α2 adrenoreceptors in breast cancer tissue. We reviewed existing literature in which dexmedetomidine was used in cancer surgeries and investigated its role in recurrence and metastasis.

Dexmedetomidine promotes the progression of hepatocellular carcinoma through hepatic stellate cell activation

Dexmedetomidine (DEX) is an anesthetic that is widely used in the clinic, and it has been reported to exhibit paradoxical effects in the progression of multiple solid tumors. In this study, we sought to explore the mechanism by which DEX regulates hepatocellular carcinoma (HCC) progression underlying liver fibrosis. We determined the effects of DEX on tumor progression in an orthotopic HCC mouse model of fibrotic liver. A coculture system and a subcutaneous xenograft model involving coimplantation of mouse hepatoma cells (H22) and primary activated hepatic stellate cells (aHSCs) were used to study the effects of DEX on HCC progression. We found that in the preclinical mouse model of liver fibrosis, DEX treatment significantly shortened median survival time and promoted tumor growth, intrahepatic metastasis and pulmonary metastasis. The DEX receptor (ADRA2A) was mainly expressed in aHSCs but was barely detected in HCC cells. DEX dramatically reinforced HCC malignant behaviors in the presence of aHSCs in both the coculture system and the coimplantation mouse model, but DEX alone exerted no significant effects on the malignancy of HCC. Mechanistically, DEX induced IL-6 secretion from aHSCs and promoted HCC progression via STAT3 activation. Our findings provide evidence that the clinical application of DEX may cause undesirable side effects in HCC patients with liver fibrosis.

Protective effects of dexmedetomidine on the survival of random flaps

BACKGROUND

Random flaps can be used to repair wounds and improve shape and functional reconstruction, but inflammation and necrosis limit their application. Modified McFarlane flap models were constructed on the backs of rats. We hypothesized that dexmedetomidine (DEX) could improve the survival rate of ischemic random flaps.

METHODS

Sixty rats were randomly divided into three groups: a low-dose DEX group (DEX-L group, 10 μg/kg/D), a high-dose DEX group (DEX-H group, 20 μg/kg/D) and a control group (0.9 % saline equivalent). On day 7 after flap construction, the survival percentage of the flap model was calculated. Hematoxylin and eosin staining (H&E) was used to evaluate the histopathological status of the flaps and microvessel density (MVD). Lead oxide/gelatin angiography was used to detect angiogenesis, and laser Doppler flow imaging (LDF) was used to detect blood perfusion. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in the middle areas of the flaps were measured to show the level of oxidative stress. The expressions of Toll-like receptor (TLR4), nuclear factor-kappa B (NF-κB), interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were detected by immunohistochemistry.

RESULTS

DEX significantly increased the average survival percentage of the flaps and reduced ischemia and necrosis of the distal end of the flaps. SOD activity significantly increased, while MDA significantly decreased, indicating that DEX reduces oxidative damage. The expression of inflammatory immunoregulatory proteins (TLR4, NF-κB) was downregulated, and the levels of inflammatory factors (IL-1β, IL-6 and TNF-α) were lower. In addition, DEX upregulated VEGF expression, promoted angiogenesis, and increased blood perfusion.

CONCLUSION

In random flap transplantation, a high dose of DEX is beneficial to flap survival.