Involvement of substance P and the NK-1 receptor in pancreatic cancer

Neurokinin-1 receptor antagonist aprepitant regulates autophagy and apoptosis via ROS/JNK in intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) has a poor prognosis and limited treatment options. Aprepitant, a selective NK-1R antagonist, can inhibit the growth of various tumours in vitro and in vivo. However, it remains unclear whether aprepitant has cytotoxic effects on iCCA.

METHODS

We measured the expression of SP/NK-1R in clinical samples of iCCA by immunohistochemistry. Then, we detected the cytotoxic effects of aprepitant on iCCA cells via MTT, EdU and colony formation assay. We constructed a subcutaneous xenograft model of BALB/c nude mice by using HCCC-9810 and RBE cell lines to explore the effects of aprepitant in vivo. To elucidate the potential mechanisms, we explored the pro-apoptotic effect of aprepitant by flow cytometric, western blotting, ROS detection and JC-1 staining. Furthermore, we detected the autophagic level of HCCC-9810 and RBE by western blotting, mRFP-eGFP-LC3 adenovirus transfection and electron microscope.

RESULTS

SP/NK-1R is significantly expressed in iCCA. Aprepitant inhibited human iCCA xenograft growth and dose-dependently decreased the viability of RBE and HCCC-9810 cells. Aprepitant-induced mitochondria-dependent apoptosis through ROS/JNK pathway. Additionally, pretreatment with z-VAD-fmk partly reversed the effect of aprepitant on cell viability, while NAC completely attenuated the cytotoxic effects of aprepitant in vitro. Furthermore, we observed the dynamic changes of autophagosome in RBE and HCCC-9810 cells treated with aprepitant.

CONCLUSION

SP/NK-1R signalling is significantly activated in iCCA and promotes the proliferation of iCCA cells. By contrast, aprepitant can induce autophagy and apoptosis in iCCA cells via ROS accumulation and subsequent activation of JNK.

Important Cells and Factors from Tumor Microenvironment Participated in Perineural Invasion

Perineural invasion (PNI) as the fourth way for solid tumors metastasis and invasion has attracted a lot of attention, recent research reported a new point that PNI starts to include axon growth and possible nerve "invasion" to tumors as the component. More and more tumor-nerve crosstalk has been explored to explain the internal mechanism for tumor microenvironment (TME) of some types of tumors tends to observe nerve infiltration. As is well known, the interaction of tumor cells, peripheral blood vessels, extracellular matrix, other non-malignant cells, and signal molecules in TME plays a key role in the occurrence, development, and metastasis of cancer, as to the occurrence and development of PNI. We aim to summarize the current theories on the molecular mediators and pathogenesis of PNI, add the latest scientific research progress, and explore the use of single-cell spatial transcriptomics in this invasion way. A better understanding of PNI may help to understand tumor metastasis and recurrence and will be beneficial for improving staging strategies, new treatment methods, and even paradigm shifts in our treatment of patients.

Expression of substance P, neurokinin 1 receptor, Ki-67 and pyruvate kinase M2 in hormone receptor negative breast cancer and evaluation of impact on overall survival

BACKGROUND

Chronic inflammation is a hallmark of cancer, and it can be stimulated by many factors. Substance P (SP), through binding to neurokinin 1 receptor (NK1R), and pyruvate kinase M2 (PKM2) play critical roles in cancer development and progression via modulating the tumor microenvironment. This study aimed to investigate the prognostic significance of SP and PKM2 in combination with NK1R and Ki-67 in hormone receptor negative (HR-ve) breast cancer.

METHODS

Immunohistochemical expression levels of SP, NK1R, PKM2, and Ki-67 were measured in 144 paraffin-embedded breast cancer tissues (77 h -ve and 67 h + ve). SP, NK1R, and PKM2 were scored semiquantitatively, while Ki-67 was obtained by the percentage of total number of tumor cells with nuclear staining. The optimal cutoff value for SP, NK1R, PKM2, and Ki-67 were assessed by Cutoff Finder.

RESULTS

High SP expression in HR -ve breast cancer was associated with TNM stage (p = 0.020), pT stage (p = 0.035), pN stage (p = 0.002), axillary lymph node metastasis (p = 0.003), and NK1R expression level (p = 0.010). In HR + ve breast cancer, SP expression was associated with HER2 status (p = 0.001) and PKM2 expression level (p = 0.012). Regarding PKM2 expression level, it significantly associated with HER2 status (p = 0.001) and history of DCIS (p = 0.046) in HR-ve tumors, and with HER2 status (p < 0.001) and SP expression level (p = 0.012) in HR + ve tumors. Survival analysis revealed that high SP level negatively impacted overall survival in HR-ve tumors that had low NK1R level (p = 0.021). Moreover, high SP negatively impacted overall survival in HR-ve tumors that had low Ki-67 level (p = 0.005). High PKM2 negatively impacted overall survival in HR-ve cases with low SP (p = 0.047).

CONCLUSION

Combined expression levels of SP with NK1R or Ki-67, and PKM2 with SP could be used to predict survival in breast cancer patients with HR-ve tumors. Our findings suggest a role of SP/NK1R pathway and PKM2 in HR-ve breast cancer pathogenesis which should be further investigated to unveil the underlying molecular mechanisms.

Transcriptome analysis revealed the role of mTOR and MAPK signaling pathways in the white strain of Hypsizygus marmoreus extracts-induced cell death of human hepatoma Hep3B cells

The aim of this study was to investigate the anticancer mechanisms of white genius mushroom (WGM). WGM is a popular edible mushroom in Taiwan and has been demonstrated to mediate potent antiproliferation effects against human Hep3B liver cancer cells in our previous study. According to next generation sequencing technology and KEGG pathway enrichment analysis, mTOR and MAPK signaling pathways were markedly changed during treatment with WGM extracts in Hep3B cells. Therefore, this study examined the effects of WGM extracts on the expression of mTOR and MAPK signaling pathway-related proteins, such as PI3K, Akt, mTOR, Ras, Raf, MEK, ERK, p38 and JNK in Hep3B cells. According to the results of immunoblotting, we demonstrated that the protein expression of the members of PI3K/Akt/mTOR and MAPK signaling pathways were involved in WGM extracts-induced cell death. Furthermore, the inhibitors of PI3K/Akt/mTOR and MAPK signaling pathways such as rapamycin, MK2206, LY3214996 and SB202190, blocked the induction of cell death and vacuoles formation induced by WGM extracts. This study also demonstrated that WGM extracts is able to inhibit Hep3B cell migration and colony formation in a dose-dependent manner. In addition to being a very popular food, WGM should be a pharmacologically safe natural agent for cancer treatment. Therefore, WGM might be designed to develop into a dietary chemopreventive agent for the cancer treatment.

Perineural invasion-associated biomarkers for tumor development

Perineural invasion (PNI) is the process of neoplastic invasion of peripheral nerves and is considered to be the fifth mode of cancer metastasis. PNI has been detected in head and neck tumors and pancreatic, prostate, bile duct, gastric, and colorectal cancers. It leads to poor prognostic outcomes and high local recurrence rates. Despite the increasing number of studies on PNI, targeted therapeutic modalities have not been proposed. The identification of PNI-related biomarkers would facilitate the non-invasive and early diagnosis of cancers, the establishment of prognostic panels, and the development of targeted therapeutic approaches. In this review, we compile information on the molecular mediators involved in PNI-associated cancers. The expression and prognostic significance of molecular mediators and their receptors in PNI-associated cancers are analyzed, and the possible mechanisms of action of these mediators in PNI are explored, as well as the association of cells in the microenvironment where PNI occurs.

Identification of Key Pathways Involved in White Strain of Hypsizygus marmoreus Extracts-Induced Cell Death of Human Hepatoma Hep3B Cells by Next Generation Sequencing

White strain of Hypsizygus marmoreus is named as white genius mushroom (WGM) and is a popular food in Taiwan. We have confirmed the cytotoxicity of WGM extracts on human Hep3B liver cancer cells. A total of 8711 significantly differential genes were identified through large-scale transcriptome sequencing. According to the KEGG pathway enrichment analysis, autophagy, mitophagy and apoptosis pathways were identified as significant in WGM extracts-treated cells. WGM extracts induced a dose-dependent generation of reactive oxygen species (ROS) and membrane-enclosed vacuoles in Hep3B cells. The inhibition of ROS by the ROS scavengers blocked the induction of cell death and vacuoles formation. We suggested that the cell death and membrane-enclosed vacuoles induced by WGM extracts are dependent on ROS production in Hep3B cells. (2E,6E)-3,7,11,15,19,23,27,31,35-Nonamethylhexatriaconta-2,6,34-triene-1,11,15,19,23,27,31-heptol and (18:2) lysophosphatidylcholine were identified in WGM extracts. In addition to being a very popular edible mushrooms, WGM may be developed into a dietary supplement or dietary chemopreventive agent for the cancer treatment.

A Substance P (SP)/Neurokinin-1 Receptor Axis Promotes Perineural Invasion of Pancreatic Cancer and Is Affected by lncRNA LOC389641

Perineural invasion (PNI) is considered to be a main reason for the poor prognosis of pancreatic cancer. In the present study, we analyzed the roles of substance P (SP)/neurokinin-1 receptor (NK-1R) and lncRNA LOC389641 in pancreatic cancer PNI. Pancreatic cancer cell lines BxPC-3 and MIAPaCa-2 were cocultured with SH-SY5Y cells and then stimulated with SP to simulate the in vivo influence of ganglia on pancreatic cancer. The BxPC-3 and MIAPaCa-2 cells were transfected with a neurokinin-1 receptor (NK-1R) overexpression vector, NK-1R silencing vector, LOC389641 overexpression vector, or LOC389641 silencing vector, respectively. The proliferative abilities of BxPC-3 and MIAPaCa-2 cells were assessed using the cell counting kit-8 and 5-ethynyl-2'-deoxyuridine (EdU) assays. Wound-healing and Transwell assays were performed to determine the migration and invasion abilities of the cells. When SP was added to the coculture system, it positively regulated cancer cell proliferation, migration, and PNI and significantly activated the NK-1R/Akt/NF-κB signaling pathway. Incubation with 100 nmol/L SP for 24 h was selected as the optimal condition for treatment. The activated NK-1R positively regulated the proliferation, migration, and invasion of pancreatic cancer cells. However, the levels of lncRNA LOC389641 and tumor necrosis factor receptor SF10A (TNFRSF10A) mRNA in BxPC-3 and MIAPaCa-2 cells were not affected by SP treatment. Overexpression or silencing of LOC389641 changed the effect of SP stimulation on pancreatic cancer PNI. When taken together, these results revealed that SP/NK-1R and LOC389641 promoted the progression of pancreatic cancer PNI. Moreover, we found that pancreatic cancer PNI promoted by the SP/NK-1R axis could be blocked by the TNFRSF10A/NF-κB pathway mediated by LOC389641.

The Prognostic Potential of Neurokinin 1 Receptor in Breast Cancer and Its Relationship with Ki-67 Index

Background

Neurokinin 1 receptor (NK1R) is a promising biomarker and therapeutic target in breast cancer. This study was aimed at investigating the expression level of NK1R in breast cancer tissues and its relationship with proliferation index as measured by Ki-67, clinicopathological characteristics of patients, and overall survival rate.

Methods

Immunohistochemical expression of NK1R and Ki-67 was measured in 164 paraffin-embedded breast cancer tissues of four molecular subtypes (42 HER2-enriched, 40 luminal A, 42 luminal B, and 40 triple negative). NK1R was scored semiquantitatively, while Ki-67 was obtained by the percentage of total number of tumor cells with nuclear staining. The optimal cutoff values for NK1R and Ki-67 were assessed by Cutoff Finder. Pearson's Chi-square (χ²) and Fisher's exact tests were used to compare the staining scores between groups. The Kaplan-Meier method with log-rank test was used for survival analysis. ANOVA and Student's t-test were used to compare group means.

Results

A total of 164 patients were included in the study which represented females with invasive ductal carcinoma. NK1R was expressed at high levels in about 34% of investigated cases. The mean Ki-67 level was about 27% and 41.5% of sample had high Ki-67 (expression level > 22%). NK1R expression levels were associated with higher tumor grade (p = 0.021) and high Ki-67 (p = 0.012). NK1R expression negatively impacted overall survival in grade II tumors (p = 0.027).

Conclusion

NK1R contributes to cellular proliferation and is associated with negative prognosis in breast cancer. These findings suggest the potential role of NK1R as a therapeutic target in breast cancer.

Tachykinins amplify the action of capsaicin on central histaminergic neurons

Substance P (SP), a product of the tachykinin 1 (Tac1) gene, is expressed in many hypothalamic neurons. Its wake-promoting potential could be mediated through histaminergic (HA) neurons of the tuberomamillary nucleus (TMN), where functional expression of neurokinin receptors (NKRs) waits to be characterized. As in the process of nociception in the peripheral nervous system (PNS) capsaicin-receptor (transient potential vanilloid 1: TRPV1) signalling is amplified by local release of histamine and SP, we tested the involvement of tachykinins in the capsaicin-induced long-lasting enhancement (LLEcaps) of HA neurons firing by investigating selective neurokinin receptor ligands in the hypothalamic mouse brain slice preparation using patch-clamp recordings in cell-attached mode combined with single-cell RT-PCR. We report that the majority of HA neurons respond to SP (EC50 3 nM), express the SP precursor tachykinin 1 (Tac1) gene and at least one of the neurokinin receptors. Responses to selective agonists of three known neurokinin receptors were sensitive to corresponding antagonists. LLEcaps was significantly impaired by the neurokinin receptor antagonists, indicating that in hypothalamus, as in the PNS, release of tachykinins downstream to TRPV1 activation is able to boost the release of histamine. The excitatory action of SP on histaminergic neurons adds another pathway to the noradrenergic and orexinergic ones to synergistically enhance cortical arousal. We show NK1R to play a prominent role on HA neurons and thus the control of wakefulness.

Substance P and Neurokinin 1 Receptor in Chronic Inflammation and Cancer of the Head and Neck: A Review of the Literature

Head and neck cancer is a growing worldwide public health problem, accounting for approximately 1,500,000 new cases and 500,000 deaths annually. Substance P (SP) is a peptide of the tachykinin family, which has roles related to a large number of physiological mechanisms in humans. The implications of SP in carcinogenesis have recently been reported through the stimulation of the neurokinin 1 receptor (NK1R), or directly, through the effects derived from the constitutive activation of NK1R. Consequently, SP/NK1R seems to play relevant roles in cancer, upregulating cell proliferation, cell migration and chronic inflammation, among other oncogenic actions. Furthermore, there is growing evidence pointing to a central role for SP in tumour progression, singularly so in laryngeal and oral squamous cell carcinomas. The current narrative review of the literature focuses on the relationship between the SP/NK1R system and chronic inflammation and cancer in the head-and-neck region. We described a role for SP/NK1R in the transition from chronic inflammation of the head and neck mucosa, to preneoplastic and neoplastic transformation and progression.

Potential in vitro therapeutic effects of targeting SP/NK1R system in cervical cancer

BACKGROUND

Cervical cancer, an aggressive gynecological cancer, seriously threatens women's health worldwide. It is recently reported that neuropeptide substance P (SP) regulates many tumor-associated processes through neurokinin-1 receptor (NK1R). Therefore, we used cervical cancer cell line (HeLa) to investigate the functional relevance of the SP/NK1R system in cervical cancer pathogenesis.

METHODS

Cellular proliferation and cytotoxicity were analyzed by colorimetric MTT assay. Quantitative real-time PCR (qRT-PCR) was used to measure mRNA expression levels of desired genes. Cell cycle distribution and apoptosis were evaluated by flow cytometry. A wound-healing assay was employed to assess migration ability.

RESULTS

We found that the truncated isoform of NK1R(NK1R-Tr) is the dominantly expressed form of the receptor in Hela cells. We also indicated that that SP increased HeLa cell proliferation while treatment with NK1R antagonist, aprepitant, inhibited HeLa cell viability in a dose and time-dependent manner. SP also alters the levels of cell cycle regulators (up-regulation of cyclin B1 along with downregulation of p21) and apoptosis-related genes (up-regulation of Bcl-2 along with downregulation of Bax) while aprepitant reversed these effects. Aprepitant also induced arrest within the G2 phase of the cell cycle and subsequent apoptosis. Furthermore, SP promoted the migrative phenotype of HeLa cells and increased MMP-2 and MMP-9 expression while aprepitant exposure significantly reversed these effects.

CONCLUSION

Collectively, our results indicate the importance of the SP / NK1R system in promoting both proliferative and migrative phenotypes of cervical cancer cells and suggest that aprepitant may be developed as a novel treatment for combating cervical cancer.

Shedding Light on the Role of Neurotransmitters in the Microenvironment of Pancreatic Cancer

Pancreatic cancer (PC) is a highly lethal malignancy with a 5-year survival rate of less than 8%. The fate of PC is determined not only by the malignant behavior of the cancer cells, but also by the surrounding tumor microenvironment (TME), consisting of various cellular (cancer cells, immune cells, stromal cells, endothelial cells, and neurons) and non-cellular (cytokines, neurotransmitters, and extracellular matrix) components. The pancreatic TME has the unique characteristic of exhibiting increased neural density and altered microenvironmental concentration of neurotransmitters. The neurotransmitters, produced by both neuron and non-neuronal cells, can directly regulate the biological behavior of PC cells via binding to their corresponding receptors on tumor cells and activating the intracellular downstream signals. On the other hand, the neurotransmitters can also communicate with other cellular components such as the immune cells in the TME to promote cancer growth. In this review, we will summarize the pleiotropic effects of neurotransmitters on the initiation and progression of PC, and particularly discuss the emerging mechanisms of how neurotransmitters influence the innate and adaptive immune responses in the TME in an autocrine or paracrine manner. A better understanding of the interplay between neurotransmitters and the immune cells in the TME might facilitate the development of new effective therapies for PC.

The substance P and neurokinin-1 receptor system in human thyroid cancer: an immunohistochemical study

To develop a new therapeutic strategy against thyroid cancer (TC), the expression of both substance P (SP) and neurokinin-1 receptor (NK-1R) must be demonstrated in TC cells. This study aims to examine by immunohistochemistry, the localization of SP and the NK-1R in human TC samples (papillary, follicular, medullary, anaplastic), in metastasis and in healthy thyroid samples. SP and the NK-1R were expressed in all normal and TC samples. In healthy glands, SP was located in follicular cells (nucleus) and colloid and NK-1R in follicular cells (cytoplasm) and stroma. In TC samples, SP was visualized in follicular cells (nucleus and cytoplasm), stroma and colloid and NK-1R in follicular cells (cytoplasm), stroma and colloid. A semiquantitative scoring system (Allred Unit Scoring System) was applied. The expression (Allred total score) of SP and NK-1R was weaker in normal thyroid glands than in TC. In comparison with TC samples, a lower intensity/proportion of SP (nucleus and cytoplasm of follicular cells; stroma) was observed in normal samples. By contrast, in the colloid of TC samples the presence of SP was lower than in normal samples. In comparison with TC samples, the presence of the NK-1R in the cytoplasm of follicular cells and colloid was lower in normal thyroid samples, whereas the expression of this receptor in the stroma was higher. The results reported in this study suggest that the NK-1R could be a new target for the treatment of TC and use of the NK-1R antagonists could serve as a new anti-TC therapeutic strategy.

miR-206 Promotes Cancer Progression by Targeting Full-Length Neurokinin-1 Receptor in Breast Cancer

Substance P plays a pivotal role in human cancer development and progression by binding to its receptor, neurokinin-1. Neurokinin-1 has 2 isoforms: full-length neurokinin-1 and truncated neurokinin-1, the latter lacking the cytoplasmic terminal 96-amino acid residues of the full-length protein. We have identified 3 candidate miR-206 target sites within the 3′-untranslated region of the full-length neurokinin-1 gene from bioinformatics database searches. In the present study, real-time quantitative polymerase chain reaction was performed to quantify the expression of miR-206, and the expression of neurokinin-1 and full-length neurokinin-1 was detected by immunohistochemistry in 82 clinical cases of breast cancer and paired adjacent normal tissues. The miR-206 target gene was demonstrated by using a dual-luciferase reporter assay, quantitative real-time polymerase chain reaction, and Western blotting. Transwell migration and invasion, colony formation, and proliferation assays were performed to evaluate the effects of miR-206 expression on various aspects of breast cancer cell behavior in vitro. We showed that miR-206 expression is upregulated in breast cancer cell lines and breast cancer tissues when compared to that in adjacent normal tissues, and full-length neurokinin-1 expression inversely correlates with Tumor Lymph Node Metastasis (TNM) stage and lymph node metastasis. Western blotting, quantitative real-time polymerase chain reaction, and dual-luciferase reporter assays demonstrated that miR-206 binds the 3′-untranslated region of full-length neurokinin-1 messenger RNA, regulating protein expression. We showed that the overexpression of miR-206 promotes breast cancer cell invasion, migration, proliferation, and colony formation in vitro. The present study furthers the current understanding of the mechanisms underlying breast cancer pathogenesis and may be useful for the development of novel targeted therapies.

Neurokinin-1 receptor is an effective target for treating leukemia by inducing oxidative stress through mitochondrial calcium overload

Substance P (SP) regulates multiple biological processes through its high-affinity neurokinin-1 receptor (NK-1R). While the SP/NK-1R signaling axis is involved in the pathogenesis of solid cancer, the role of this signaling pathway in hematological malignancy remains unknown. Here, we demonstrate that NK-1R expression is markedly elevated in the white blood cells from acute myeloid leukemia patients and a panel of human leukemia cell lines. Blocking NK-1R induces apoptosis in vitro and in vivo via increase of mitochondrial reactive oxygen species. This oxidative stress was triggered by rapid calcium flux from the endoplasmic reticulum into mitochondria and, consequently, impairment of mitochondrial function, a mechanism underlying the cytotoxicity of NK-1R antagonists. Besides anticancer activity, blocking NK-1R produces a potent antinociceptive effect in myeloid leukemia-induced bone pain by alleviating inflammation and inducing apoptosis. These findings thus raise the exciting possibility that the NK-1R antagonists, drugs currently used in the clinic for preventing chemotherapy-induced nausea and vomiting, may provide a therapeutic option for treating human myeloid leukemia.

Nerves and Pancreatic Cancer: New Insights into a Dangerous Relationship

Perineural invasion (PNI) is defined as the presence of neoplastic cells along nerves and/or within the different layers of nervous fibers: epineural, perineural and endoneural spaces. In pancreatic cancer-particularly in pancreatic ductal adenocarcinoma (PDAC)-PNI has a prevalence between 70 and 100%, surpassing any other solid tumor. PNI has been detected in the early stages of pancreatic cancer and has been associated with pain, increased tumor recurrence and diminished overall survival. Such an early, invasive and recurrent phenomenon is probably crucial for tumor growth and metastasis. PNI is a still not a uniformly characterized event; usually it is described only dichotomously ("present" or "absent"). Recently, a more detailed scoring system for PNI has been proposed, though not specific for pancreatic cancer. Previous studies have implicated several molecules and pathways in PNI, among which are secreted neurotrophins, chemokines and inflammatory cells. However, the mechanisms underlying PNI are poorly understood and several aspects are actively being investigated. In this review, we will discuss the main molecules and signaling pathways implicated in PNI and their roles in the PDAC.

The role of sensory innervation in cornea-lens regeneration

BACKGROUND

Numerous sensory nerves in the cornea contribute to normal tissue homeostasis. Interestingly, cells within the basal corneal epithelium can regenerate new lenses in the frog, Xenopus. In this study, we investigated whether cornea sensory nerves or their neuropeptides are important for supporting cornea-lens regeneration.

RESULTS

Attempts to sever the trigeminal nerve trunk, which provides sensory nerve branches to the cornea, did not inhibit lens regeneration. However, using this approach we found that it was not possible to completely disrupt sensory innervation, as these nerves are able to quickly regenerate back to the cornea. On the other hand, attenuation of neuropeptide levels with capsaicin was found to significantly inhibit lens regeneration, as visualized by a reduction of Substance P. These treatments also led to a reduction of cornea sensory innervation. Interestingly, inhibition of the Substance P-preferred receptor NK-1 with Spantide II did not affect lens-regeneration rates.

CONCLUSIONS

This study provides evidence that cornea nerves support cornea-lens regeneration, which could occur through the release of various neurotrophic factors. Substance P, however, does not appear to be the critical component of this signaling pathway. Further studies are needed to investigate what role other known neurotrophic factors may play in this process.

Innervation of cervical carcinoma is mediated by cancer-derived exosomes

OBJECTIVE

Recently, our laboratory identified sensory innervation within head and neck squamous cell carcinomas (HNSCCs) and subsequently defined a mechanism whereby HNSCCs promote their own innervation via the release of exosomes that stimulate neurite outgrowth. Interestingly, we noted that exosomes from human papillomavirus (HPV)-positive cell lines were more effective at promoting neurite outgrowth than those from HPV-negative cell lines. As nearly all cervical tumors are HPV-positive, we hypothesized that these findings would extend to cervical cancer.

METHODS

We use an in vitro assay with PC12 cells to quantify the axonogenic potential of cervical cancer exosomes. PC12 cells are treated with cancer-derived exosomes, stained with the pan-neuronal marker (β-III tubulin) and the number of neurites quantified. To assess innervation in cervical cancer, we immunohistochemically stained cervical cancer patient samples for β-III tubulin and TRPV1 (sensory marker) and compared the staining to normal cervix.

RESULTS

Here, we show the presence of sensory nerves within human cervical tumors. Additionally, we show that exosomes derived from HPV-positive cervical cancer cell lines effectively stimulate neurite outgrowth.

CONCLUSIONS

These data identify sensory nerves as components of the cervical cancer microenvironment and suggest that tumor- derived exosomes promote their recruitment.

SP/NK-1R promotes gallbladder cancer cell proliferation and migration

Aberrant substance P/neurokinin‐1 receptor (SP/NK‐1R) system activation plays a critical role in various disorders, however, little is known about the expression and the detailed molecular mechanism of the SP and NK‐1R in gallbladder cancer (GBC). In this study, we firstly analyzed the expression and clinical significance of them in patients with GBC. Then, cellular assays were performed to clarify their biological role in GBC cells. Moreover, we investigated the molecular mechanisms regulated by SP/NK‐1R. Meanwhile, mice xenografted with human GBC cells were analyzed regarding the effects of SP/NK1R complex in vivo. Finally, patient samples were utilized to investigate the effect of SP/NK‐1R. The results showed that SP and NK‐1R were highly expressed in GBC. We found that SP strongly induced GBC cell proliferation, clone formation, migration and invasion, whereas antagonizing NK‐1R resulted in the opposite effects. Moreover, SP significantly enhanced the expression of NF‐κB p65 and the tumor‐associated cytokines, while, Akt inhibitor could reverse these effects. Further studies indicated that decreasing activation of NF‐κB or Akt diminished GBC cell proliferation and migration. In consistent with results, immunohistochemical staining showed high levels of Akt, NF‐κB and cytokines in tumor tissues. Most importantly, the similar conclusion was obtained in xenograft mouse model. Our findings demonstrate that NK‐1R, after binding with the endogenous agonist SP, could induce GBC cell migration and spreading via modulation of Akt/NF‐κB pathway.

Evaluation of serum level of substance P and tissue distribution of NK-1 receptor in breast cancer

Breast cancer is the second leading cause of cancer death in women with increasing incidence. Hence, finding a diagnostic factor and/or potential drug target could lead to an earlier diagnosis or a more effective therapeutic protocol. It is shown that substance P (SP) through its receptor neurokinin-1 (NK1R) could initiate tumor cell proliferation, angiogenesis, and migration. This was a case-control study on 41 women with breast cancer and 34 healthy controls. Serum level of SP was measured using an ELISA method, and immunohistochemistry staining was performed to study NK1R expression in different cell compartments. Assessing serum SP values of patients showed significantly higher levels than those of healthy individuals. However, no significant correlation was found between SP levels and tumor criteria, but between SP and HER-2. Moreover, the percentage, intensity of staining as well as tissue distribution of NK1R were significantly higher in tumor tissues as compared with controls. Increased serum SP levels and NK1R tissue distribution were observed in patients with breast cancer as compared with their controls, highlighting the involvement of SP/NK1R complex in breast cancer incidence. NK1R profound expression in tumor cell cytoplasm and its significant correlation with the majority of cancer features can be of importance to be taken into consideration as a possible potential therapeutic target in future targeted therapeutic strategies. Furthermore, cytoplasmic expression of NK1R can be suggested as a potent prognostic factor as it has shown significant correlation with TNM and tumor grade.

Neuropeptide-induced modulation of carcinogenesis in a metastatic breast cancer cell line (MDA-MB-231LUC+)

Background

Metastatic cancer to bone is well-known to produce extreme pain. It has been suggested that the magnitude of this perceived pain is associated with disease progression and poor prognosis. These data suggest a potential cross-talk between cancer cells and nociceptors that contribute not only to pain, but also to cancer aggressiveness although the underlying mechanisms are yet to be stablished.

Methods

The in vitro dose dependent effect of neuropeptides (NPs) (substance P [SP], calcitonin gene-related peptide and neurokinin A [NKA]) and/or its combination, on the migration and invasion of MDA-MB-231^LUC+ were assessed by wound healing and collagen-based cell invasion assays, respectively. The effect of NPs on the expression of its receptors (SP [NK1] and neurokinin A receptors [NK2], CALCRL and RAMP1) and kininogen (high-molecular-weight kininogen) release to the cell culture supernatant of MDA-MB-231^LUC+, were measured using western-blot analysis and an ELISA assay, respectively. Statistical significance was tested using one-way ANOVA, repeated measures ANOVA, or the paired t-test. Post-hoc testing was performed with correction for multiple comparisons as appropriate.

Results

Our data show that NPs strongly modify the chemokinetic capabilities of a cellular line commonly used as a model of metastatic cancer to bone (MDA-MB-231^LUC+) and increased the expression of their receptors (NK1R, NK2R, RAMP1, and CALCRL) on these cells. Finally, we demonstrate that NPs also trigger the acute release of HMWK (Bradykinin precursor) by MDA-MB-231^LUC+, a molecule with both tumorigenic and pro-nociceptive activity.

Conclusions

Based on these observations we conclude that NPs exposure modulates this breast cancer cellular line aggressiveness by increasing its ability to migrate and invade new tissues. Furthermore, these results also support the pro nociceptive and cancer promoter role of the peripheral nervous system, during the initial stages of the disease.

Utilizing Peptide Ligand GPCRs to Image and Treat Pancreatic Cancer

It is estimated that early detection of pancreatic ductal adenocarcinoma (PDAC) could increase long-term patient survival by as much as 30% to 40% (Seufferlein, T. et al., Nat. Rev. Gastroenterol. Hepatol.2016, 13, 74–75). There is an unmet need for reagents that can reliably identify early cancerous or precancerous lesions through various imaging modalities or could be employed to deliver anticancer treatments specifically to tumor cells. However, to date, many PDAC tumor-targeting strategies lack selectivity and are unable to discriminate between tumor and nontumor cells, causing off-target effects or unclear diagnoses. Although a variety of approaches have been taken to identify tumor-targeting reagents that can effectively direct therapeutics or imaging agents to cancer cells (Liu, D. et al., J. Controlled Release2015, 219, 632–643), translating these reagents into clinical practice has been limited, and it remains an area open to new methodologies and reagents (O’Connor, J.P. et al., Nat. Rev. Clin. Oncol. 2017, 14, 169–186). G protein–coupled receptors (GPCRs), which are key target proteins for drug discovery and comprise a large proportion of currently marketed therapeutics, hold significant promise for tumor imaging and targeted treatment, particularly for pancreatic cancer.

Substance P Promotes the Progression of Endometrial Adenocarcinoma

OBJECTIVES

It has been demonstrated that substance P (SP) promotes while neurokinin-1 receptor (NK-1R) antagonist inhibits the proliferation of several human cancer cells. Currently, it is still unknown whether such actions exist in human endometrial carcinoma. This study aimed to explore the role of SP/NK-1R signaling in the progression of endometrial adenocarcinoma.

MATERIALS AND METHODS

The expression levels of SP and NK-1R in endometrial adenocarcinoma tissues and Ishikawa cell line were detected by real-time quantitative PCR and Western blot analysis. The effects of SP on Ishikawa cells proliferation and invasion were analyzed using MTT assay and transwell matrigel invasion assay, respectively. The expression levels of matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor C (VEGF-C) in Ishikawa cells after administration of SP were detected by real-time quantitative RCR and Western blot analysis.

RESULTS

The expression levels of SP and NK-1R were significantly higher in endometrial adenocarcinoma tissues and Ishikawa cells than in normal endometrium. Substance P significantly enhanced the proliferation and invasion of Ishikawa cells. In addition, SP induced the expression of MMP-9 and VEGF-C in Ishikawa cells, whereas NK-1R antagonist inhibited these effects.

CONCLUSIONS

Substance P plays an important role in the development of endometrial carcinoma by inducing the expression of MMP-9 and VEGF-C and promoting cancer cell proliferation and metastasis, which can be blocked by NK-1R antagonist.

Can Stopping Nerves, Stop Cancer?

The nervous system is viewed as a tissue affected by cancer and as a conduit for the transmission of cancer pain and perineural invasion. Here, we review recent studies that indicate a more direct role. Several studies have shown that reducing stress or suppressing sympathetic drive correlates with improved outcomes and prolonged survival. Recent studies using animal models of visceral and somatic cancer further support a role for the nervous system in cancer progression. Specifically, nerve ablation had a profound impact on disease progression, including delayed development of precancerous lesions, and decreased tumor growth and metastasis. In this review, we summarize new evidence and discuss how future studies may address the role of neural signaling in the modulation of tumorigenesis.

Substance P expresses in intrapancreatic ganglia of the rats

Substance P (SP) is an important neuropeptide regulating the functions of the pancreas and might play a vital role in the onset of diabetes. SP has been shown to express in nerve fibers of the pancreas, but whether SP exists in the intrapancreatic ganglia, which are components of a complex autonomous nervous system to co-ordinate the functions of the pancreas, is unsure. The aim of this study was to systematically investigate rat intrapancreatic ganglia and the expression of SP in intrapancreatic ganglia. After surgical denervation of posterior branches of bilateral T₅-L₂ dorsal root ganglia, SP expression remained >60% in the pancreas. Moreover, after high doses of capsaicin were injected to destroy sensory nerves, the remainder of SP protein levels was still >50% in the pancreas. In the intrapancreatic ganglia, for anti-SP polyclonal antibody, the immunoreactivity to SP was found in 34.0±1.2% of PGP 9.5-positive intrapancreatic neurons (47 ganglia from 13 rats); for anti-SP monoclonal antibody, the immunoreactivity to SP was found in 26.6±1.0% of PGP 9.5-positive intrapancreatic neurons (18 ganglia from 6 rats). In summary, the present molecular and immunocytochemistry studies showed that there existed intrinsic SP expression in the neurons of intrapancreatic ganglia, which constituted around half of SP origins in the pancreas suggesting that intrapancreatic ganglia might play an important role on mechanisms involving SP.

Targeting NK-1 Receptors to Prevent and Treat Pancreatic Cancer: a New Therapeutic Approach

Pancreatic cancer (PC) is the fourth leading cause of cancer related-deaths in both men and women, and the 1- and 5-year relative survival rates are 25% and 6%, respectively. It is known that smoking, alcoholism and psychological stress are risk factors that can promote PC and increase PC progression. To date, the prevention of PC is crucial because there is no curative treatment. After binding to the neurokinin-1 (NK-1) receptor (a receptor coupled to the stimulatory G-protein Gαs that activates adenylate cyclase), the peptide substance P (SP)-at high concentrations-is involved in many pathophysiological functions, such as depression, smoking, alcoholism, chronic inflammation and cancer. It is known that PC cells and samples express NK-1 receptors; that the NK-1 receptor is overexpressed in PC cells in comparison with non-tumor cells, and that nanomolar concentrations of SP induce PC cell proliferation. By contrast, NK-1 receptor antagonists exert antidepressive, anxiolytic and anti-inflammatory effects and anti-alcohol addiction. These antagonists also exert An antitumor action since in vitro they inhibit PC cell proliferation (PC cells death by apoptosis), and in a xenograft PC mouse model they exert both antitumor and anti-angiogenic actions. NK-1 receptor antagonists could be used for the treatment of PC and hence the NK-1 receptor could be a new promising therapeutic target in PC.

CUSP9* treatment protocol for recurrent glioblastoma: aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, ritonavir, sertraline augmenting continuous low dose temozolomide

CUSP9 treatment protocol for recurrent glioblastoma was published one year ago. We now present a slight modification, designated CUSP9*. CUSP9* drugs--aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, sertraline, ritonavir, are all widely approved by regulatory authorities, marketed for non-cancer indications. Each drug inhibits one or more important growth-enhancing pathways used by glioblastoma. By blocking survival paths, the aim is to render temozolomide, the current standard cytotoxic drug used in primary glioblastoma treatment, more effective. Although esthetically unpleasing to use so many drugs at once, the closely similar drugs of the original CUSP9 used together have been well-tolerated when given on a compassionate-use basis in the cases that have come to our attention so far. We expect similarly good tolerability for CUSP9*. The combined action of this suite of drugs blocks signaling at, or the activity of, AKT phosphorylation, aldehyde dehydrogenase, angiotensin converting enzyme, carbonic anhydrase -2,- 9, -12, cyclooxygenase-1 and -2, cathepsin B, Hedgehog, interleukin-6, 5-lipoxygenase, matrix metalloproteinase -2 and -9, mammalian target of rapamycin, neurokinin-1, p-gp efflux pump, thioredoxin reductase, tissue factor, 20 kDa translationally controlled tumor protein, and vascular endothelial growth factor. We believe that given the current prognosis after a glioblastoma has recurred, a trial of CUSP9* is warranted.

Substance P and the neurokinin-1 receptor regulate electroencephalogram non-rapid eye movement sleep slow-wave activity locally

The neuropeptide substance P is an excitatory neurotransmitter produced by various cells including neurons and microglia that is involved in regulating inflammation and cerebral blood flow--functions that affect sleep and slow-wave activity (SWA). Substance P is the major ligand for the neurokinin-1 receptor (NK-1R), which is found throughout the brain including the cortex. The NK-1R is found on sleep-active cortical neurons expressing neuronal nitric oxide synthase whose activity is associated with SWA. We determined the effects of local cortical administration of a NK-1R agonist (substance P-fragment 1, 7) and a NK-1R antagonist (CP96345) on sleep and SWA in mice. The NK-1R agonist significantly enhanced SWA for several hours when applied locally to the cortex of the ipsilateral hemisphere as the electroencephalogram (EEG) electrode but not after application to the contralateral hemisphere when compared to saline vehicle control injections. In addition, a significant compensatory reduction in SWA was found after the NK-1R agonist-induced enhancements in SWA. Conversely, injections of the NK-1R antagonist into the cortex of the ipsilateral hemisphere of the EEG electrode attenuated SWA compared to vehicle injections but this effect was not found after injections of the NK-1R antagonist into contralateral hemisphere as the EEG electrode. Non-rapid eye movement sleep and rapid eye movement sleep duration responses after NK-1R agonist and antagonist injections were not significantly different from the responses to the vehicle. Our findings indicate that the substance P and the NK-1R are involved in regulating SWA locally.