The mu-opioid receptor is a molecular marker for poor prognosis in hepatocellular carcinoma and represents a potential therapeutic target

Effects of opioid drugs on immune function in cancer patients

Opioid receptor agonists are often used when cancer patients undergo surgery or analgesic treatment. As analgesics in clinical care, opioids can provide intraoperative or to chronic cancer pain relief. Immune function plays an important role in anti-cancer therapy, with cellular immunity, comprised principally of T-lymphocytes and natural killer cells, representing the primary anti-cancer immune response. However, it remains unclear whether immune function is further affected with the use of opioids in already immunocompromised cancer patients. This article provides a review of the effects of commonly used clinical opioids, including morphine, oxycodone, fentanyl and tramadol, on immune function in cancer patients. It provides a summary of current evidence regarding the immunomodulatory effects of opioids in the cancer setting and mechanisms underlying these interactions.

Opioids and Cancer: Current Understanding and Clinical Considerations

Pain is one of the most common symptoms in patients with cancer. Pain not only negatively affects the quality of life of patients with cancer, but it has also been associated with reduced survival. Pain management is therefore a critical component of cancer care. Prescription opioids remain the first-line approach for the management of moderate-to-severe pain associated with cancer. However, there has been increasing interest in understanding whether these analgesics could impact cancer progression. Furthermore, epidemiological data link a possible association between prescription opioid usage and cancer development. Until more robust evidence is available, patients with cancer with moderate-to-severe pain may receive opioids to decrease suffering. However, future studies should be conducted to evaluate the role of opioids and opioid receptors in specific cancers.

Impact of Protein Phosphatase Expressions on the Prognosis of Hepatocellular Carcinoma Patients

The study was conducted to unveil the significance of protein phosphatases in the prognosis of hepatocellular carcinoma (HCC) patients and its related molecular biological attributes as well as to discover novel potential biomarkers for therapeutic significance and diagnostic purposes that may benefit clinical practice. Analyzing a data set from 159 HCC patients using high-throughput phosphoproteomics, we examined the dysregulated expression of protein phosphatases. Employing bioinformatic and pathway analyses, we explored differentially expressed genes linked to protein phosphatases. A protein-protein interaction network was constructed using the search tool for the retrieval of interacting genes/proteins database. We quantified a total of 11,547 phosphorylation sites associated with 4043 phosphoproteins from HCC patients. Within this data set, we identified 105 identified phosphorylation sites associated with protein phosphatases; 28 genes were upregulated and 3 were downregulated in HCC. Enriched pathways using Gene Set Enrichment Analysis encompassed oocyte meiosis, proteoglycans in cancer, the oxytocin signaling pathway, the cGMP-PKG signaling pathway, the vascular smooth muscle, and the cAMP signaling pathway. The Kyoto encyclopedia of genes and genomes (KEGG) analysis highlighted pathways like mitogen-activated protein kinase, AMPK, and PI3K-Akt, indicating potential involvement in HCC progression. Notably, the PPI network identified hub genes, emphasizing their interconnections and potential roles in HCC. In our study, we found significantly upregulated levels of CDC25C, PPP1R13L, and PPP1CA, which emerge as promising avenues. This significant expression could serve as potent diagnostic and prognostic markers to enhance the effectiveness of HCC cancer treatment, offering efficiency and accuracy in patient assessment. The findings regarding protein phosphatases reveal their elevated expression in HCC, correlating with unfavorable prognosis. Moreover, the outcomes of gene ontology and KEGG pathway analyses suggest that protein phosphatases may influence liver cancer by engaging diverse targets and pathways, ultimately fostering the progression of HCC. These results underscore the substantial potential of protein phosphatases as key contributors to HCC's development and advancement. This insight holds promise for identifying therapeutic targets and charting research avenues to enhance the comprehension of the intricate molecular mechanisms underpinning HCC.

Problems with opioids - beyond misuse

The U.S. is grappling with an opioid epidemic, with millions of adults on long-term opioid therapy (LTOT). Although patients often report pain relief and improved daily function with opioids, research shows no significant differences in short-term outcomes between opioid and non-opioid users, as well as no long-term opioid benefits. This scoping review aims to identify lesser-known side effects of long-term opioid use and increase awareness of them, allowing healthcare providers and patients to better assess the risks and benefits of opioid use. Our data search from PubMed and Google Scholar used keywords related to opioids, chronic pain, hypogonadism, endocrinopathies, cancer progression, cardiovascular events, renovascular events, sleep disturbances, mood disorders and others, narrowing down to English-language full articles published from January 2018 to April 2023. This review emphasizes the probable serious adverse consequences of long-term opioid use on various body systems in patients with chronic pain. Given the lack of long-term benefits and significant adverse effects, our review underscores the critical need for healthcare providers to include these risks in discussions with patients when considering the long-term use of opioid therapy.

Tumour excisional surgery, anaesthetic-analgesic techniques, and oncologic outcomes: a narrative review

Cancer is a growing global burden; there were an estimated 18 million new cancer diagnoses worldwide in 2020. Excisional surgery remains one of the main treatments for solid organ tumours in cancer patients and is potentially curative. Cancer- and surgery-induced inflammatory processes can facilitate residual tumour cell survival, growth, and subsequent recurrence. However, it has been hypothesised that anaesthetic and analgesic techniques during surgery might influence the risk of cancer recurrence. This narrative review aims to provide an updated summary of recent observational studies and new randomised controlled clinical trials on whether certain specific anaesthetic and analgesic techniques or perioperative interventions during tumour resection surgery of curative intent materially affect long-term oncologic outcomes.

PI3K/AKT signaling pathway as a critical regulator of epithelial-mesenchymal transition in colorectal tumor cells

Colorectal cancer (CRC) is one of the most frequent gastrointestinal malignancies that are considered as a global health challenge. Despite many progresses in therapeutic methods, there is still a high rate of mortality rate among CRC patients that is associated with poor prognosis and distant metastasis. Therefore, investigating the molecular mechanisms involved in CRC metastasis can improve the prognosis. Epithelial-mesenchymal transition (EMT) process is considered as one of the main molecular mechanisms involved in CRC metastasis, which can be regulated by various signaling pathways. PI3K/AKT signaling pathway has a key role in CRC cell proliferation and migration. In the present review, we discussed the role of PI3K/AKT pathway CRC metastasis through the regulation of the EMT process. It has been shown that PI3K/AKT pathway can induce the EMT process by down regulation of epithelial markers, while up regulation of mesenchymal markers and EMT-specific transcription factors that promote CRC metastasis. This review can be an effective step toward introducing the PI3K/AKT/EMT axis to predict prognosis as well as a therapeutic target among CRC patients. Video Abstract.

No association of postoperative opioid usage with long-term surgery outcomes in patients with liver cancer: a population-based retrospective cohort study

ABSTRACT

Hepatocellular carcinoma (HCC) is a fatal cancer worldwide, and surgical resection remains the standard treatment. Postoperative opioid prescription has been believed to affect cancer recurrence through complex biological pathways. We conducted a retrospective cohort study using the Longitudinal Health Insurance Database of Taiwan to evaluate the relationship between postoperative opioid use and long-term surgical outcomes of patients with HCC. This study had a retrospective cohort design. In total, 812 patients older than 20 years who underwent hepatectomy because of HCC were included. The exposure group comprised patients who used opioids during hospitalization postoperatively. The comparison group included those who never used opioids during hospitalization postoperatively. A Cox proportional hazards model was used to evaluate the overall survival or recurrence-free survival rate between the opioid group and the nonopioid group. A total of 530 patients received opioids postoperatively and 282 patients did not. The hazard ratios of overall survival and recurrence-free survival were 1.10 (95% confidence interval [CI], 0.85-1.41) and 1.15 (95% CI, 0.91-1.46), respectively. Total postoperative opioids were converted into oral morphine milligram equivalents and then divided into 3 equal subgroups: low dose, <40 mg; medium dose, 40 to 144 mg; and high dose, ≥145 mg. The hazard ratios of overall survival were 0.88 (95% CI, 0.63-1.24) for the low-dose group, 1.27 (95% CI, 0.92-1.74) for the medium-dose group, and 1.14 (95% CI, 0.83-1.58) for the high-dose group. Postoperative opioids do not affect overall and recurrence-free survival in patients undergoing hepatectomy or liver transplantation because of HCC. Cancer recurrence should not be a clinical concern regarding postoperative opioid prescription.

Mu opioid receptor mRNA overexpression predicts poor prognosis among 18 common solid cancers: A pan-cancer analysis

Background

Opioids are widely used for patients with solid tumors during surgery and for cancer pain relief. We conducted a pan-cancer genomic analysis to investigate the prognostic features of Mu opioid receptor (MOR) mRNA expression across 18 primary solid cancers.

Methods

All the data of cancer with MOR mRNA were retrieved from cBioPortal for Cancer Genomics. Logistic regression was used to determine the associations between MOR mRNA expression and clinicopathological features. Log-rank test and Cox regression was used for survival analysis. Subgroup analysis and propensity score matching were also carried out.

Results

7,274 patients, including 1,112 patients with positive MOR mRNA expression, were included for data analyses. Positive MOR mRNA expression was associated with more advanced stage of T (adjusted Odds ratio [OR], 1.176; 95% confidence interval [CI], 1.022-1.354; P=0.024), M (adjusted OR, 1.548; 95% CI, 1.095-2.189; P=0.013) except N (adjusted OR, 1.145; 95% CI, 0.975-1.346; P=0.101), and worse prognosis for overall survival (Hazard ratio [HR] 1.347, 95% CI 1.200-1.512, P&lt;0.001), progression-free survival (HR 1.359, 95% CI 1.220-1.513, P&lt;0.001), disease-free survival (HR 1.269, 95% CI 1.016-1.585, P&lt;0.001) and disease-specific survival (HR 1.474, 95% CI 1.284-1.693, P&lt;0.001). Patients with positive MOR mRNA expression tended to be classified as tumor microenvironment immune types II, representing low PD-L1 and low CD8A expression.

Conclusion

MOR mRNA overexpression is associated with poor prognosis and poor response to PD-L1 therapy.

μ-opioid receptor agonist facilitates circulating tumor cell formation in bladder cancer via the MOR/AKT/Slug pathway: a comprehensive study including randomized controlled trial

BACKGROUND

μ-opioid receptor agonists (MORAs) are indispensable for analgesia in bladder cancer (BC) patients, both during surgery and for chronic pain treatment. Whether MORAs affect BC progression and metastasis remains largely unknown. This study focused on the effects of MORAs on the formation of circulating tumor cells (CTCs) in BC and aimed to provide potential therapeutic targets, which would retain the pain-relieving effects of MORAs in BC patients without sacrificing their long-term prognosis.

METHODS

Different preclinical models were used to identify the effects of MORAs on the progression of BC. A novel immunocapture microfluidic chip was utilized to analyze whether MORAs affected the number of CTCs in mouse models and clinical BC patients. Bioinformatic analyses, total transcriptome sequencing, and molecular biology methods were then used to investigate the underlying mechanisms in these models and in BC cell lines.

RESULTS

Mouse models of hematogenous metastasis and in situ BC demonstrated that tumor metastasis was significantly increased after MORA treatment. A significant increase in the number of mesenchymal and/or epithelial CTCs was detected after MORA treatment in both the mouse models and clinical trial patients. Mechanistically, MORAs facilitated the formation of CTCs by activating the MOR/PI3K/AKT/Slug signaling pathway, hereby promoting the epithelial-mesenchymal transition (EMT) of BC cells, as knockdown of MOR, Slug or blockade of PI3K inhibited the EMT process and CTC formation.

CONCLUSION

MORAs promoted BC metastasis by facilitating CTC formation. The EMT-CTC axis could be targeted for preventive measures during MORA treatment to inhibit the associated tumor metastasis or recurrence in BC patients.

Effect of Opioid Receptor Activation and Blockage on the Progression and Response to Treatment of Head and Neck Squamous Cell Carcinoma

Recent studies suggest that opioids have a role in the progression of HNSCC mediated by mu opioid receptors (MOR), however, the effects of their activation or blockage remains unclear. Expression of MOR-1 was explored in seven HNSCC cell lines using Western blotting (WB). XTT cell proliferation and cell migration assays were performed on four selected cell lines (Cal-33, FaDu, HSC-2, and HSC-3), treated with opiate receptor agonist (morphine), antagonist (naloxone), alone and combined with cisplatin. All four selected cell lines display an increased cell proliferation and upregulation of MOR-1 when exposed to morphine. Furthermore, morphine promotes cell migration, while naloxone inhibits it. The effects on cell signaling pathways were analyzed using WB, demonstrating morphine activation of AKT and S6, key proteins in the PI3K/AKT/mTOR axis. A significant synergistic cytotoxic effect between cisplatin and naloxone in all cell lines is observed. In vivo studies of nude mice harboring HSC3 tumor treated with naloxone demonstrate a decrease in tumor volume. The synergistic cytotoxic effect between cisplatin and naloxone is observed in the in vivo studies as well. Our findings suggest that opioids may increase HNSCC cell proliferation via the activation of the PI3K/Akt/mTOR signaling pathway. Moreover, MOR blockage may chemo-sensitize HNSCC to cisplatin.

Evaluating the expression pattern of the opioid receptor in pituitary neuroendocrine tumors (PitNET) and the role of morphine and naloxone in the regulation of pituitary cell line growth and apoptosis

PURPOSE

The expression pattern of the opioid receptor (MOR) in pituitary neuroendocrine tumors (PitNET) and the possible effect of morphine and naloxone on GH3 cell growth and apoptosis were evaluated.

METHODS

The 114 pituitary tissues including non-functioning, GH-producing and ACTH-producing PitNET and healthy cadaver pituitary tissues were included. The expression level of the MOR gene and protein was assessed using real-time PCR and Western blot. The association with patient demographic characteristics was assessed. Morphine and naloxone were applied to assess their possible pharmacological role in GH3 pituitary adenoma cell death. The cytotoxic effect, the apoptosis rate, the cell cycle distribution, the content of reactive oxygen species and the caspase 3 activity were measured.

RESULTS

MOR gene levels increased significantly in pituitary neuroendocrine tumors (PitNET) compared to the healthy pituitary samples. The increased level of MOR gene expression was prominent in invasive functional and non-functional pituitary tumors. A consistent expression pattern was demonstrated for MOR protein levels in PitNET samples. A dose- and time-dependent reduction in the rate of GH3 pituitary cells was observed after morphine treatment with an IC50 of 483 µM after 24 h of incubation. Morphine induced early apoptosis, accumulation of cells in sub-G1 phase, increase in cellular ROS levels and caspase-3 activity. The observed effects of morphine were reversed after MOR blockade using 10 and 25 µM naloxone.

CONCLUSION

The possible contributing role of the MOR in pituitary tumor cell growth and the putative pharmaceutical effect of morphine in pituitary neuroendocrine tumor cell death (PitNET) is illustrated.

Dopamine receptor D3 is related to prognosis in human hepatocellular carcinoma and inhibits tumor growth

Background

Dopamine receptors have been reported to play important roles in cancer progression. However, the role of dopamine receptor D3 (DRD3) in hepatocellular carcinoma (HCC) remains unclear.

Methods

The expression of DRD3 was detected by immunohistochemistry and real-time qPCR. The prognostic value of DRD3 in patients was investigated by analyzing selected databases, including cBioPortal and Kaplan–Meier plotter. Cell growth was tested by CCK8 assay, and Transwell assays were performed to assess cancer cell migration and invasion. The cAMP/ERK/CREB signaling pathway was evaluated by Western blot analysis and ELISA. An HCC xenograft model was established for in vivo experiments.

Results

DRD3 mRNA expression was significantly higher in nontumor tissues than in tumor tissues. Lower protein expression of DRD3 was related to poor recurrence-free survival (RFS) and overall survival (OS). Kaplan–Meier plotter analysis showed that higher expression of DRD3 mRNA was associated with better OS, RFS, disease-specific survival (DSS), and progression-free survival (PFS). cBioPortal analysis revealed that the alteration group, which harbored genetic mutations in DRD3, exhibited poor OS, RFS, DSS and PFS. According to CCK8 and Transwell assays, stable DRD3 overexpression cell line (ex-DRD3-SK-HEP-1) showed weaker proliferation, migration and invasion behaviors. PD128907, a DRD3 agonist, suppressed proliferation, migration and invasion in HCC cell lines, while U99194, a DRD3 antagonist, enhanced proliferation, migration and invasion in HCC cell lines. Western blot analysis and ELISA revealed that stable DRD3 knock-down cell line (sh-DRD3-PLC/PRF/5) and U99194 both increased the protein levels of cAMP, p-ERK and p-CREB; on the other hand, ex-DRD3-SK-HEP-1 and PD128907 decreased the protein levels of cAMP, p-ERK and p-CREB. SCH772984, an ERK antagonist, abolished the effect of U99194 on the malignant biological behaviors of HCC cells. In vivo, PD128907 suppressed tumor growth, and U99194 enhanced tumor growth.

Conclusion

Our results suggest that down-regulation of DRD3 is strongly involved in the progression of HCC, and DRD3 might be consider as an independent prognostic factor for HCC. Furthermore, DRD3 agonists may be a promising strategy for HCC therapy.

Effect of Opioids on Survival in Patients with Cancer

Opioids are commonly used for pain management in patients with cancer. They have a range of unwanted effects, including some that potentially influence cancer growth. This article reviews the data assessing the effects of opioids on survival in patients with cancer. Many studies assessing this show an association between opioids and decreased survival. This effect is present even at very low doses of opioids. These studies do not assess causality, so it is not known if it is a direct effect of opioids on survival. As the control groups are not matched to the opioid group it might be that opioids are being used to control pain and patients receiving opioids have more aggressive cancers and it is the underlying cancer which is causing the decreased survival. Furthermore, although some studies allude to different opioids having different effects on survival, often all opioids are pooled in analysis. Future work needs to try to ascertain causality and differentiate between different opioids, pain, and cancer-mediated effects on survival in specific cancer types. Until then, opioids should continue to be used in patients with cancer as part of measures to optimise comfort and quality of life.

MOR promotes epithelial-mesenchymal transition and proliferation via PI3K/AKT signaling pathway in human colorectal cancer

The mu-opioid receptor (MOR), a membrane-bound G protein-coupled receptor, is implicated in progression and long-term outcome of several types of tumors. However, the expression and clinical significance of MOR in colorectal cancer (CRC) remain unclear. In this study, a total of 180 paraffin-embedded samples of paired tumors and normal tissues from CRC patients are used to explore expression levels of MOR by immunohistochemistry (IHC). Results show that MOR is highly expressed in tumors compared with that in paired normal tissues (P<0.0001). MOR expression levels are associated with the degree of differentiation (P<0.001) and the regional lymph node metastasis (P<0.001). In addition, a significant difference is also found in the overall survival (OS) between MOR low- and high-expression groups (P=0.002), especially in patients with TNM stage III or IV CRC (P=0.007). Both univariate (P=0.002) and multivariate (P=0.013) analyses indicated that MOR is an independent risk factor associated with CRC prognosis. We further investigate the mechanism in MOR-positive CRC cell line HCT116. The results show that silencing of MOR significantly suppresses epithelial-mesenchymal transition (EMT), in addition to suppressing cell proliferation, migration, and invasion. In addition, the expression of downstream p-AKT is also significantly downregulated, and the above suppression effect could be rescued by PI3K/AKT signaling agonist. We conclude that MOR mediates EMT via PI3K/AKT signaling, facilitating lymph node metastasis and resulting in poor survival of CRC patients. Our findings suggest that MOR is a novel prognostic indicator and the application of opioid receptor antagonists may be a novel therapeutic strategy for CRC patients with high MOR expression.

Antagonists of the Mu-Opioid Receptor in the Cancer Patient: Fact or Fiction?

Purpose of Review

Antagonists of mu-opioid receptor role in cancer progression remains to be elucidated. The objective of this review was to summarize the available evidence on antagonists of mu-opioid receptor effect on tumor progression and prognosis in different types of cancers and an evaluation of the available findings on their mechanism of action.

Recent Findings

We have found studies related to methylnaltrexone (MNTX) and naltrexone (NTX) usage in cancer outcomes-related setting. We found consistent preclinical evidence of a potential action of MNTX and NTX on cancer growth and spread mediated mainly by effect on the opioid growth factor receptor (OGFr) axis, which results in depressed cell replication. However, clinical results are scarce and limited to poor-quality evidence.

Summary

Further high-quality studies are warranted to study antagonists of mu-opioid receptor role as a therapeutic option in different types of cancer, especially in patients where the classical treatment causes unacceptable side effects.

Chronic Cancer Pain: Opioids within Tumor Microenvironment Affect Neuroinflammation, Tumor and Pain Evolution

Pain can be a devastating experience for cancer patients, resulting in decreased quality of life. In the last two decades, immunological and pain research have demonstrated that pain persistence is primarily caused by neuroinflammation leading to central sensitization with brain neuroplastic alterations and changes in pain responsiveness (hyperalgesia, and pain behavior). Cancer pain is markedly affected by the tumor microenvironment (TME), a complex ecosystem consisting of different cell types (cancer cells, endothelial and stromal cells, leukocytes, fibroblasts and neurons) that release soluble mediators triggering neuroinflammation. The TME cellular components express opioid receptors (i.e., MOR) that upon engagement by endogenous or exogenous opioids such as morphine, initiate signaling events leading to neuroinflammation. MOR engagement does not only affect pain features and quality, but also influences directly and/or indirectly tumor growth and metastasis. The opioid effects on chronic cancer pain are also clinically characterized by altered opioid responsiveness (tolerance and hyperalgesia), a hallmark of the problematic long-term treatment of non-cancer pain. The significant progress made in understanding the immune-mediated development of chronic pain suggests its exploitation for novel alternative immunotherapeutic approaches.

Opioid Receptor Expression in Colorectal Cancer: A Nested Matched Case-Control Study

Background

There is growing interest in the possible effect of perioperative anesthetic management on the growth and spread of cancer. The impact of perioperative use of opioids on cancer recurrence remains controversial and an assessment cannot yet be established based on current publications. This study aimed to assess the differential expression of opioid receptors between healthy and tumor tissues in patients with stage II and III colorectal cancer undergoing elective surgery by immunohistochemistry (IHC).

Methods

Propensity-score matched case-control study nested in a retrospective cohort of patients with stage II or III colorectal. The primary endpoint was the difference in µ-opioid receptor (MOR) expression measured by IHC between tumor and healthy tissue in subject with or without recurrence. Secondary endpoints were to evaluate the differences in Opioid Growth Factor Receptor (OGFR), cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) in the matched sample and from a from samples of colorectal cancer stored in the Cancer Genome Atlas (TCGA) and Genotype Tissue Expression Project (GTEx).

Results

There was a significant difference in MOR receptor (median 3 [intequartile range IQR: 1-3] and 0 [IQR: 0-2], P<0.001) and OGFR receptor (median 6 [IQR: 5-6] and 2 [IQR: 1-2], P<0.001) in tumor and control tissue respectively. However, there were no significant differences in cAMP nor PKA expression between both types of tissues and in expression in any of the analyzed variables by recurrence status. The MOR and OGFR expression data from TCGA database were similar to our sample size data with lower expression of MOR and higher expression of OGFR in tumoural samples with a skewed distribution for MOR expression in tumor tissue both in patients with and without recurrence.

Conclusion

In patients with stage II and III colorectal cancer, overall expression of MOR and OGFR was significantly increased but was not different between previously matched patients with or without recurrence. No differences were found in the analyzed metabolic pathway of cAMP-PKA: These results were confirmed by an in silico analysis of samples from the TCGA-GTEx database.

Agonists Specific for κ-Opioid Receptor Induces Apoptosis of HCC Cells Through Enhanced Endoplasmic Reticulum Stress

Cancer pain is an important factor affecting life quality of patients especially in the advanced stage and relieving pain is one of fundamental strategies for cancer treatment. Opioids such as morphine are the most widely used in clinics. However, they have been reported to be associated with the occurrence and development of several types of cancer. Thus, search for an opioid that has analgesic effect and can retard cancer progress simultaneously is critical for cancer management. In this study, we first examined the expression of μ and κ (MOR and KOR) in cell lines and tumor tissues of hepatocellular carcinoma (HCC), a malignant tumor with high mortality, and then compared the effects of opioid receptors-specific agonists on malignant phenotypes of HCC cells in vitro and tumor growth in an HCC xenograft mouse model. KOR and MOR were found to be highly expressed in HCC cell lines and HCC tissues. The KOR-specific agonist U50488h, oxycodone (agonist for both KOR and MOR) and the MOR-specific agonist morphine inhibited HCC cell proliferation, while only U50488h and oxycodone suppressed colony formation and migration of HCC cells. U50488h and oxycodone, but not morphine, induced HCC apoptosis. Further detection of PERK, GRP78 and CHOP revealed that PERK signaling was upregulated by treatment with U50488h, while treatment with the PERK inhibitor GSK2656157 partially reversed the promotion of apoptosis and inhibition of cell proliferation by U50488h, indicating that endoplasmic reticulum stress is associated with its suppressing effect on HCC malignant phenotypes. Similar to the in vitro results, HCC growth was significantly reduced by administration of U50488h and oxycodone, but not by morphine, in the HCC xenograft mouse model. PERK and caspase-3 in the HCC tissues were up-regulated by U50488h treatment as detected by immunohistochemistry and western blotting. Taken together, our results revealed that activation of KOR by U50488h inhibited malignant phenotypes of HCC both in vitro and in vivo, while activation of MOR by morphine did not have such effect. Because of their dual roles in the relief of pain and in the suppression of malignant phenotypes, opioids such as U50488h that act on KOR should be considered as the first choice for HCC management.

Oncological drug discovery: AI meets structure-based computational research

The integration of machine learning and structure-based methods has proven valuable in the past as a way to prioritize targets and compounds in early drug discovery. In oncological research, these methods can be highly beneficial in addressing the diversity of neoplastic diseases portrayed by the different hallmarks of cancer. Here, we review six use case scenarios for integrated computational methods, namely driver prediction, computational mutagenesis, (off)-target prediction, binding site prediction, virtual screening, and allosteric modulation analysis. We address the heterogeneity of integration approaches and individual methods, while acknowledging their current limitations and highlighting their potential to bring drugs for personalized oncological therapies to the market faster.

Solid Tumor Opioid Receptor Expression and Oncologic Outcomes: Analysis of the Cancer Genome Atlas and Genotype Tissue Expression Project

Background

Opioid receptors are expressed not only by neural cells in the central nervous system, but also by many solid tumor cancer cells. Whether perioperative opioids given for analgesia after tumor resection surgery might inadvertently activate tumor cells, promoting recurrence or metastasis, remains controversial. We analysed large public gene repositories of solid tumors to investigate differences in opioid receptor expression between normal and tumor tissues and their association with long-term oncologic outcomes.

Methods

We investigated the normalized gene expression of µ, κ, δ opioid receptors (MOR, KOR, DOR), Opioid Growth Factor (OGFR), and Toll-Like 4 (TLR4) receptors in normal and tumor samples from twelve solid tumor types. We carried out mixed multivariable logistic and Cox regression analysis on whether there was an association between these receptors' gene expression and the tissue where found, i.e., tumor or normal tissue. We also evaluated the association between tumor opioid receptor gene expression and patient disease-free interval (DFI) and overall survival (OS).

Results

We retrieved 8,780 tissue samples, 5,852 from tumor and 2,928 from normal tissue, of which 2,252 were from the Genotype Tissue Expression Project (GTEx) and 672 from the Cancer Genome Atlas (TCGA) repository. The Odds Ratio (OR) [95%CI] for gene expression of the specific opioid receptors in the examined tumors varied: MOR: 0.74 [0.63-0.87], KOR: 1.27 [1.17-1.37], DOR: 1.66 [1.48-1.87], TLR4: 0.29 [0.26-0.32], OGFR: 2.39 [2.05-2.78]. After controlling all confounding variables, including age and cancer stage, there was no association between tumor opioid receptor expression and long-term oncologic outcomes.

Conclusion

Opioid receptor gene expression varies between different solid tumor types. There was no association between tumor opioid receptor expression and recurrence. Understanding the significance of opioid receptor expression on tumor cells remains elusive.

Comprehensive Analysis to Identify the Encoded Gens of Sodium Channels as a Prognostic Biomarker in Hepatocellular Carcinoma

The SCN family as the encoded gens of sodium channels has been proven to participate in development of cancers including hepatocellular carcinoma (HCC), but the prognostic value of the SCN family is unclear. The results of the UALCAN database had showed that SCN2A/4A/5A/8A mRNA were highly expressed in tumour tissues, while SCN1A/7A/11A mRNA were expressed at low levels (p < 0.05), furthermore, the expression of SCN4A and SCN7A had the similar levels in microarray analysis result. The pan-tumour analysis showed that SCN7A expression was stably lower in tumours than SCN4A expression by TIMER. Both SCN4A and SCN7A were related to tumour grade, nodal metastatic status, histological subtype, patient race, individual cancer stages and TP53 mutation status to varying degrees. The Kaplan–Meier plotter demonstrated that high SCN4A mRNA expression was correlated with better overall survival (OS), disease-specific survival (DSS) and progression-free survival (PFS) and that high expression of SCN7A mRNA was associated with better OS; however, in Asians, higher SCN4A was correlated with better OS and DSS, and higher SCN7A was well correlated with better OS, recurrence-free survival (RFS), DSS and PFS. Analysis of data from cBioPortal showed that mutation of SCN7A was related to RFS and PFS. The protein expression of SCN4A and SCN7A had been detected by Immunohistochemistry. Univariate survival analysis revealed that high SCN7A protein expression was significantly linked to better OS (p = 0.001) and RFS (p = 0.003). Moreover, SCN7A displayed as an independent prognostic factor by multivariate analysis. In addition, a lower methylation level indicated a poor outcome. Pathway and functional enrichment analysis predicted a relationship between SCN7A and the PI3K pathway. In conclusion, there are significant and stable changes in SCN4A and SCN7A expression in HCC. SCN7A expression has better prognostic value and might participate in HCC progression.

Subcutaneous Methylnaltrexone for Treatment of Opioid-Induced Constipation in Cancer versus Noncancer Patients: An Analysis of Efficacy and Safety Variables from Two Studies

Purpose

Methylnaltrexone inhibits opioid-induced constipation (OIC) by binding to peripheral µ-opioid receptors without impacting central opioid receptor mediated analgesia. This analysis compared methylnaltrexone efficacy and safety among advanced illness patients with and without active cancer and OIC.

Patients and Methods

This post hoc analysis included two multicenter, randomized, double-blind, placebo-controlled studies in adults with advanced illness and OIC who received subcutaneous methylnaltrexone. Efficacy endpoints included the proportion of patients achieving rescue-free laxation (RFL), time to RFL, weekly laxations within 24 hours after dosing, rescue laxative use, and pain scores. Adverse events were monitored for safety.

Results

After pooling, 178 patients received methylnaltrexone (n = 116 with cancer) and 185 received placebo (n = 114 with cancer). Median baseline daily opioid morphine equivalents (mg/d) were higher in cancer (methylnaltrexone: 180; placebo: 188) versus noncancer patients (methylnaltrexone: 120; placebo: 80). The proportions of patients achieving RFL within 4 hours after ≥2 of the first 4 doses were significantly greater with methylnaltrexone (cancer: 56.9%; noncancer: 58.1%) versus placebo (cancer: 5.3%; noncancer: 11.3%; P < 0.0001). The median time to laxation within 24 hours after the first methylnaltrexone dose was significantly shorter in cancer and noncancer patients versus placebo (cancer: 0.96 vs 22.53 hours, P < 0.0001; noncancer: 1.25 vs >24 hours, P = 0.0002). The mean number of weekly laxations within 24 hours after dosing by week 2 was significantly higher in methylnaltrexone- vs placebo-treated cancer and noncancer patients (cancer: 7.9 vs 4.9, P < 0.0001; noncancer: 8.4 vs 5.0, P < 0.0001). Methylnaltrexone reduced rescue laxative use without impacting pain scores. Consistent with previous data, methylnaltrexone was well tolerated in cancer and noncancer patients, and the AE profile did not suggest symptoms of opioid withdrawal.

Conclusion

Methylnaltrexone reduced RFL time in advanced-illness patients with and without active cancer, while maintaining pain control with opioid treatment despite higher baseline opioid use among cancer patients.

The influence of brain metastases on the central nervous system effects of methylnaltrexone: a post hoc analysis of 3 randomized, double-blind studies

PURPOSE

Peripherally acting μ-opioid receptor antagonists such as methylnaltrexone (MNTX, Relistor®) are indicated for the treatment of opioid-induced constipation (OIC). The structural properties unique to MNTX restrict it from traversing the blood-brain barrier (BBB); however, the BBB may become more permeable in patients with brain metastases. We investigated whether the presence of brain metastases in cancer patients compromises the central effects of opioids among patients receiving MNTX for OIC.

METHODS

This post hoc analysis of pooled data from 3 randomized, placebo-controlled trials included cancer patients with OIC who received MNTX or placebo. Endpoints included changes from baseline in pain scores, rescue-free laxation (RFL) within 4 or 24 h of the first dose, and treatment-emergent adverse events (TEAEs), including those potentially related to opioid withdrawal symptoms.

RESULTS

Among 356 cancer patients in the pooled population, 47 (MNTX n = 27; placebo n = 20) had brain metastases and 309 (MNTX n = 172; placebo n = 137) did not have brain metastases. No significant differences in current pain, worst pain, or change in pain scores from baseline were observed between patients treated with MNTX or placebo. Among patients with brain metastases, a significantly greater proportion of patients who received MNTX versus placebo achieved an RFL within 4 h after the first dose (70.4% vs 15.0%, respectively, p = 0.0002). TEAEs were similar between treatment groups and were generally gastrointestinal in nature and not related to opioid withdrawal.

CONCLUSION

Focal disruptions of the BBB caused by brain metastases did not appear to alter central nervous system penetrance of MNTX.

Xanthomicrol suppresses human hepatocellular carcinoma cells migration and invasion ability via Μu-opioid receptor

BACKGROUND

Xanthomicrol is one of the methoxylated flavones and a promising cancer chemopreventive agent, but its anti-migration and anti-invasion ability on human hepatocellular carcinoma (HCC) remains unknown.

OBJECTIVES

This study aims to explore Xanthomicrol's effects on migration and invasion ability of the human HCC Huh7 cell line.

METHODS

Viability of Huh7 cells was measured by cell counting kit-8 (CCK8) assay. Cell apoptosis was assayed with flow cytometry analysis. The ability of migration and invasion of Huh7 cells was then detected through Transwell assays. Epithelial-mesenchymal transition (EMT)-related proteins were also detected through Western blot.

KEY FINDINGS

Xanthomicrol inhibits the migration and invasion of Huh7 cells. The overexpression of Μu-opioid receptor (MOR) increases Huh7 cells' proliferation and enhances migration and invasion ability, while xanthomicrol treatment decreases the expression of MOR. Moreover, xanthomicrol can reverse migration, invasion and EMT-related protein expression by overexpressed MOR.

CONCLUSIONS

These results suggest that xanthomicrol is a potential MOR antagonist, and it possesses potent anti-migration and anti-invasion ability on Huh7 cells.

Targeting the mu-Opioid Receptor for Cancer Treatment

PURPOSE OF REVIEW

Opioids are still the most effective and widely used treatments for acute and chronic pain in cancer patients. This review focuses on the impact of opioids and mu-opioid receptors (MOR) on tumor progression and providing new ideas for targeting the MOR in cancer treatment.

RECENT FINDINGS

Studies estimated that opioids facilitate tumor progression and are related to the worse prognosis in cancer patients. As the primary receptor of opioids, MOR is involved in the regulation of malignant transformation of tumors and participating in proliferation, invasion, metastasis, and angiogenesis. MOR may be a new molecular marker of malignant tumors and thus become a new target for cancer therapy, which may be beneficial to the outcomes of cancer patients.

Morphine promotes tumorigenesis and cetuximab resistance via EGFR signaling activation in human colorectal cancer

Morphine, a mu-opioid receptor (MOR) agonist, has been extensively used to treat advanced cancer pain. In particular, in patients with cancer metastasis, both morphine and anticancer drugs are given simultaneously. However, evidence showed that morphine might be a risk factor in promoting the tumor's malignant potential. In this study, we report that treatment with morphine could activate MOR and lead to the promotion of proliferation, migration, and invasion in HCT116 and DLD1 colorectal cancer (CRC) cells with time-concentration dependence. Moreover, morphine can also contribute to cetuximab's drug resistance, a targeted drug widely used to treat advanced CRC by inducing the activation of epidermal growth factor receptor (EGFR). The cell phenotype includes proliferation, migration, invasion, and drug resistance, which may be reversed by MOR knockdown or adding nalmefene, the MOR receptor antagonist. Receptor tyrosine kinase array analysis revealed that morphine selectively induced the transactivation of EGFR. EGFR transactivation resulted in the activation of ERK1/2 and AKT. In conclusion, morphine induces the transactivation of EGFR via MOR. It activates the downstream signal pathway AKT-MTOR and RAS-MAPK, increases proliferation, migration, and invasion, and promotes resistance to EGFR inhibitors in a CRC cell line. Furthermore, we verified that EGFR inhibition by cetuximab strongly reversed the protumoral effects of morphine in vitro and in vivo. Collectively, we provide evidence that morphine-EGFR signaling might be a promising therapeutic target for CRC patients, especially for cetuximab-resistant CRC patients.

Identification and validation of a new gene signature predicting prognosis of hepatocellular carcinoma patients by network analysis of stemness indices

Background: Stem cells play an important role in hepatocellular carcinoma (HCC). However, their precise effect on HCC tumorigenesis and progression remains unclear. The present study aimed to characterize stem cell-related gene expression in HCC.Methods: The mRNA expression-based stemness index (mRNAsi) was used to analyze the clinical characteristics and prognosis of HCC patients. The weighted gene co-expression network analysis (WGCNA) was used to construct a gene co-expression network of 374 HCC patients. Finally, six genes were used to construct the prognosis signature.Results: HCC patients had a higher mRNAsi score than healthy people, suggesting poor prognosis. Two gene modules highly related to mRNAsi were identified. Multivariate Cox analysis was carried out to establish a Cox proportional risk regression model. The risk score for each patient was the sum of the product of each gene expression and its coefficient. Survival analysis suggested that the low-risk group had a significantly better prognosis.Conclusions: The established six-gene signature was able to predict patient prognosis accurately. This new signature should be verified in prospective studies in order to determine patient prognosis in clinical decision-making.

Dezocine, An Opioid Analgesic, Exerts Antitumor Effects in Triple-Negative Breast Cancer by Targeting Nicotinamide Phosphoribosyltransferase

Opioids are a potential adjuvant treatment for certain cancers; while they are primarily used to relieve chronic pain, these drugs may also affect cancer progression and recurrence. Dezocine is one opioid commonly used in China, but its effects on cancer cells are unknown. Here, we demonstrated the inhibitory effect of dezocine on triple-negative breast cancer (TNBC) cells, and determined the underlying molecular mechanism. We found that dezocine suppressed cell proliferation, migration and invasion, and induced apoptosis in TNBC cells. Xenograft models demonstrated the inhibitory effects of dezocine treatment on TNBC tumor growth in vivo. The anticancer effects of dezocine were independent of opioid receptors, which are not highly expressed by normal breast or breast cancer tissues. A pull-down assay and LC-MS/MS analysis indicated that dezocine directly targets NAMPT: computer modeling verified that the free energy of dezocine kinetically bound into the pocket of NAMPT was −17.4 kcal/mol. Consequently, dezocine treatment inhibited NAMPT enzyme activity, resulting in cellular NAD abolishment. We confirmed the dezocine-induced inhibition of cell proliferation by both NAMPT knockdown and upon treatment with the inhibitor FK866. Our results suggest that both dezocine and NAMPT might represent novel therapeutic targets for TNBC.

The kappa opioid receptor may be a potential tumor suppressor by regulating angiogenesis in breast cancer

Our hypothesis proposes that activating κ-opioid receptors (KORs) may inhibit the progression of breast cancer and improve patient prognosis. Consequently, KORs may become a promising therapeutic target for breast cancer. Activating KORs induces not only analgesic efficacy comparable to μ-opioid receptors but also shows a promising antitumor effect and with fewer opioid-induced adverse effects. Based on present studies and our bioinformatics analysis of KORs, we propose that KORs can function as a tumor suppressor by inhibiting angiogenesis in human breast cancer; therefore, analgesics that mainly activate KORs would be more suitable for breast cancer patients.

Opioids and premature biochemical recurrence of prostate cancer: a randomised prospective clinical trial

BACKGROUND

Prostate cancer is one of the most prevalent neoplasms in male patients, and surgery is the main treatment. Opioids can have immune modulating effects, but their relation to cancer recurrence is unclear. We evaluated whether opioids used during prostatectomy can affect biochemical recurrence-free survival.

METHODS

We randomised 146 patients with prostate cancer scheduled for prostatectomy into opioid-free anaesthesia or opioid-based anaesthesia groups. Baseline characteristics, perioperative data, and level of prostate-specific antigen every 6 months for 2 yr after surgery were recorded. Prostate-specific antigen >0.2 ng ml^-1 was considered biochemical recurrence. A survival analysis compared time with biochemical recurrence between the groups, and a Cox regression was modelled to evaluate which variables affect biochemical recurrence-free survival.

RESULTS

We observed 31 biochemical recurrence events: 17 in the opioid-free anaesthesia group and 14 in the opioid-based anaesthesia group. Biochemical recurrence-free survival was not statistically different between groups (P=0.54). Cox regression revealed that biochemical recurrence-free survival was shorter in cases of obesity (hazard ratio [HR] 1.63, confidence interval [CI] 0.16-3.10; p=0.03), high D'Amico risk (HR 1.58, CI 0.35-2.81; P=0.012), laparoscopic surgery (HR 1.6, CI 0.38-2.84; P=0.01), stage 3 tumour pathology (HR 1.60, CI 0.20-299) and N1 status (HR 1.34, CI 0.28-2.41), and positive surgical margins (HR 1.37, CI 0.50-2.24; P=0.002). The anaesthesia technique did not affect time to biochemical recurrence (HR -1.03, CI -2.65-0.49; P=0.18).

CONCLUSIONS

Intraoperative opioid use did not modify biochemical recurrence rates and biochemical recurrence-free survival in patients with intermediate and high D'Amico risk prostate cancer undergoing radical prostatectomy.

CLINICAL TRIAL REGISTRATION

NCT03212456.

Opioids and cancer prognosis: A summary of the clinical evidence

Pain is a common and devastating symptom among cancer patients. It can be caused by the cancer itself or by certain therapies like surgery, radiation or chemotherapy. Opioids are the first line of treatment for moderate to severe cancer-related pain. Opioids alone or in combination with non-opioid analgesics and adjuvant medications are important components for pain management during the perioperative period for cancer patients. Opioids act on the μ-opioid receptor (MOR), which is expressed in cancer cells and non-malignant cells of the tumor microenvironment. Retrospective studies suggest an association between the expression of MOR in cancers and shorter survival. In addition, recent evidence suggests that opium use and prescription opioids can influence clinical oncological outcomes. In this review, we will summarize the clinical evidence regarding the effect of opioid administration and survival in patients with cancer as well as the current evidence involving MOR expression and cancer progression.

β-endorphin at the intersection of pain and cancer progression: Preclinical evidence

We examined the association between endogenous opioid β-endorphin, cancer progression and pain in a transgenic mouse model of breast cancer, with a rat C3(1) simian virus 40 large tumor antigen fusion gene (C3TAg). C3TAg mice develop ductal epithelial atypia at 8 weeks, progression to intra-epithelial neoplasia at 12 weeks, and invasive carcinoma with palpable tumors at 16 weeks. Consistent with invasive carcinoma at 4 months of age, C3TAg mice demonstrate a significant increase in hyperalgesia compared to younger C3TAg or control FVBN mice without tumors. Our data show that the growing tumor contributes to circulating β-endorphin. As an endogenous ligand of mu opioid receptor, β-endorphin has analgesic activity. Paradoxically, we observed an increase in pain in transgenic breast cancer mice with significantly high circulating and tumor-associated β-endorphin. Increased circulating β-endorphin correlates with increasing tumor burden. β-endorphin induced the activation of mitogenic and survival-promoting signaling pathways, MAPK/ERK 1/2, STAT3 and Akt, observed by us in human MDA-MB-231 cells suggesting a role for β-endorphin in breast cancer progression and associated pain.

Identification of CDC25C as a Potential Biomarker in Hepatocellular Carcinoma Using Bioinformatics Analysis

Hepatocellular carcinoma (HCC) is the most aggressive type of gastrointestinal tumor, with a high rate of mortality. However, identifying biomarkers for the treatment of HCC remains to be developed. We aimed to determine whether cell division cycle 25C (CDC25C) could be used as a novel diagnostic and therapeutic biomarker in HCC. Expression of CDC25C in HCC was analyzed by using GEPIA (Gene Expression Profiling Interactive Analysis) and UALCAN databases. GEPIA and CBioPortal databases were applied to analyze patients’survival and CDC25C mutations, respectively. PPI (Protein-Protein Interaction) network was further built by STRING (Search Tool for the Retrieval of Interacting Genes) and Metascape Web portals. To the best of our knowledge, the novel observations identified in the present study reveal that the expression of CDC25C in HCC was significantly enhanced when compare to that in normal liver tissues (P < 0.001). A higher CDC25C expression resulted in a remarkably shorter disease free survival as well as overall survival. Moreover, the expression of CDC25C in HCC was related to HCC patients’grade and race, but not gender. The expression levels of CDC25C elevated gradually from stage 1 to 3 but decreased in stage 4. The specific gene mutations V41A, L87 H, N222 K and X309-splice of CDC25C occurred in HCC samples and these unique mutations were not detected in any other tumor tissues. Finally, PPI networks and GO enrichment analysis suggested that CDC25C might be associated with cell cycle and p53 signaling pathway. Taken together, bioinformatics analysis revealed that CDC25C might be a potential diagnostic predictor for HCC.

Increased dopamine and its receptor dopamine receptor D1 promote tumor growth in human hepatocellular carcinoma

Background

Dopamine and dopamine receptor D1 (DRD1), a member of the dopamine receptor family, have been indicated to play important roles in cancer progression, but dopamine secretion in hepatocellular carcinoma (HCC) and the effects of DRD1 on HCC remain unclear. This study was designed to explore the contribution of the dopaminergic system to HCC and determine the relationship between DRD1 and prognosis in HCC patients.

Methods

The dopamine metabolic system was monitored using enzyme‐linked immunosorbent assays (ELISAs). The expression of DRD1 was detected by microarray analysis, immunohistochemistry (IHC), and quantitative real‐time PCR (qRT‐PCR). Stable DRD1 knockout and overexpression cell lines were established for investigation. Transwell, colony formation, and Cell Counting Kit 8 (CCK8) assays were performed to assess the malignant behaviors of cancer cells. The cAMP/PI3K/AKT/ cAMP response element‐binding (CREB) signaling pathway was evaluated by Western blot. This pathway, which is agitated by DRD1 in striatal neurons, had been proven to participate in tumor progression. Xenograft HCC tumors were generated for in vivo experiments.

Results

Dopamine secretion increased locally in HCC due to an imbalance in dopamine metabolism, including the upregulation of dopa decarboxylase (DDC) and the downregulation of monoamine oxidase A (MAOA). Dopamine promoted the proliferation and metastasis of HCC. DRD1 was highly expressed in HCC tissues and positive DRD1 expression was related to a poor prognosis in HCC patients. The upregulation of DRD1 agitated malignant activities, including proliferation and metastasis in HCC by regulating the cAMP/PI3K/AKT/CREB pathway, and the downregulation of DRD1 had opposing effects. The effects of dopamine on HCC was reversed by depleting DRD1. SCH23390, a selective DRD1 antagonist, inhibited the proliferation and metastasis of HCC cells both in vitro and in vivo.

Conclusion

Dopamine secretion was locally increased in HCC and promoted HCC cell proliferation and metastasis. DRD1 was found to exert positive effects on HCC progression and play a vital role in the dopamine system, and could be a potential therapeutic target and prognostic biomarker for HCC.

Supraglottic Carcinoma in Intravenous Opioid Drug Abusers: A Distinct Disease with Improved Survival

OBJECTIVES/HYPOTHESIS

Recent evidence indicates an increased prevalence of intravenous opioid drug abusers (IVDAs) among supraglottic squamous cell carcinoma (SG-SCC) patients. This study investigates whether the clinical course of SG-SCC in IVDA differs from SG-SCC in non-IVDA.

STUDY DESIGN

A retrospective case-control study conducted in a in two tertiary referral centers.

METHODS

This case-control study compares IVDA with non-IVDA patients diagnosed and treated for SG-SCC in between 2005 and 2018. Disease-free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier estimator. Adjusted odds ratios (ORs) for mortality were calculated using multivariant analyses.

RESULTS

A total of 124 patients were included; 21% (26) were IVDA, and 79% (98) were non-IVDA. Age at diagnosis in the IVDA group versus the non-IVDA group was 53 and 66 years, respectively (P = .001). Nevertheless, the age hazard ratio for OS was calculated and found to have minimal to no effect, 1.05 (95% Cl: 1.025-1.076). Otherwise, the two groups were comparable regarding demographics, other risk factors (i.e., gender, smoking, and alcohol), and comorbidities status, as well as the comparable stage at diagnosis, histologic grading, and treatment modalities. Although the DFS was comparable in both groups, the 5-year OS was 55% in the IVDA group compared with 34% among the non-IVDA patients (P = .04). In multivariant analyses for mortality, positive IVDA history was found to be protective, adjusted OR: 0.263 (95% CI: 0.081-0.854). Similarly, within the subgroup of 100 patients with advanced-stage disease (III and IV), the adjusted OR was 0.118 (95% CI: 0.028-0.495).

CONCLUSIONS

SG-SCC in IVDA patients has a distinct clinical course, presenting at a younger age, and may have improved prognosis.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E1190-E1197, 2021.

Increased mu-opioid receptor expression is associated with reduced disease-free and overall survival in laryngeal squamous cell carcinoma

BACKGROUND

Expression of the mu-opioid receptor (MOR) is associated with poor long-term outcomes in various types of cancer. The association between MOR expression and clinical outcomes in laryngeal squamous cell carcinoma (LSCC) is not clear.

METHODS

This retrospective study included patients who underwent laryngectomy for LSCC. The expression pattern of the MOR protein and OPRM1 gene in tumours and corresponding adjacent non-carcinoma specimens was measured. Propensity score matching was used to minimise bias. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The secondary endpoints were intraoperative sufentanil consumption, grade of surgical complications according to the Clavien-Dindo classification, and hospital length of stay.

RESULTS

A total of 207 LSCC patients were enrolled. After propensity score matching, there was a significant difference in DFS between groups at 1, 3, and 5 yr (60.2% vs 81.2%, P=0.019; 39.4% vs 50.2%, P=0.026; 37.5% vs 42.5%, P=0.023, respectively) in patients with high MOR expression. The OS rates at 1, 3, and 5 yr were significantly lower in the high MOR expression group (81.2% vs 93.2%, P=0.027; 57.7% vs 78.3%, P<0.001; 42.5% vs 60.3%, P<0.001, respectively). The multivariate analysis indicated that high MOR expression was associated with worse DFS and OS (hazard ratio: 1.52, 95% confidence interval: 1.07, 2.25, P=0.034; hazard ratio: 1.42, 95% confidence interval: 1.17, 2.34, P=0.032).

CONCLUSION

High MOR expression may be associated with poor prognosis in patients with LSCC, suggesting that MOR could be used as a valuable molecular biomarker to predict prognosis of LSCC patients.

Opioids and Cancer Mortality

OPINION STATEMENT

Opioids are the gold standard for the treatment of cancer-related pain. Preclinical studies have associated opioids with cancer progression and overall survival. In mice models, opioids have been shown to possess pro-tumor activity secondary to immunosuppression, migration of tumor cells, increased activity of vascular endothelial growth factor receptors, and angiogenesis leading to tumor progression. In contrast, opioids have also been associated with having antitumor activity by activation of apoptosis and phagocytosis. However, high-quality randomized controlled trials in humans that are focused on the association between opioids and survival in cancer patients are lacking, which underscores the importance of being cautious when interpreting the results of the preclinical studies. Cancer-related pain is complex and multifactorial and may worsen as the disease progresses leading to higher opioid utilization. Moreover, cancer pain by itself has been associated with poor survival. The survival in these advanced cancer patients taking opioids may be more likely to be associated with cancer progression and not the opioid use. Adequate treatment of cancer pain has the potential to improve quality of life and performance status, highlighting the importance of continuing to use opioids to manage pain efficiently. More research is clearly needed.

Evaluation of Receptor Affinity, Analgesic Activity and Cytotoxicity of a Hybrid Peptide, AWL3020

In the present contribution we report design, synthesis and evaluation of receptor affinity, analgesic activity and cytotoxicity of a hybrid peptide, AWL3020. The peptide includes two pharmacophores, one of δ-opioid receptor (δOR) agonists and one of neurokinin-1 receptor (NK1R) antagonists. The design was motivated by the desire to obtain a compound with strong analgesic action and potential additional antiproliferative action. The compound displays high δOR affinity (IC50 = 29.5 nM). On the other hand, it has only poor affinity for the NK1R (IC50 = 70.28 μM). The substance shows good analgesic action which is however weaker than that of morphine. Regarding the effect on proliferation, the compound exhibits no pro-proliferative action in the assayed range. In higher concentrations, it has also cytotoxic activity. This effect is however not selective. The strongest effect of AWL3020 was found for melanoma MeW164 cell line (EC50 = 46.27 μM in reduction of cell numbers after a few days of incubation; EC50 = 37.78 μM in MTT assay).

Mu Opioid Receptor 1 (MOR-1) Expression in Colorectal Cancer and Oncological Long-Term Outcomes: A Five-Year Retrospective Longitudinal Cohort Study

Preclinical evidence has shown increased expression of mu opioid receptor 1 (MOR-1) in colorectal cancer although its association with disease-free and overall survival (DFS and OS) has not been investigated. We hypothesized that MOR-1 was overexpressed in tumor samples compared to normal tissue and this was associated with decreased DFS and OS. We carried out a retrospective study assessing the association of MOR-1 tumor expression with long-term outcomes by immunohistochemistry in normal and tumor samples from 174 colorectal cancer patients. The primary endpoint was five years of DFS. Secondary endpoints were five years of OS, the difference in MOR-1 expression between normal and tumor tissue and the occurrence of postoperative complications. Multivariable Cox regression showed no significant association between MOR-1 expression and DFS (HR 0.791, 95% CI 0.603–1.039, p = 0.092). MOR-1 expression was higher in tumor tissue compared to non-tumor tissue. No associations were found between MOR-1 expression and OS or postoperative complications. These findings suggest that although MOR-1 is over-expressed in colorectal cancer samples there is no association to increased risk of recurrence or mortality. Future studies are warranted to elucidate the role of cancer stage, genetic polymorphism, and quantitative assessment of MOR-1 over-expression on long-term outcomes in colorectal cancer.