Marisa Rosso

The NK-1 Receptor Is Expressed in Human Primary Gastric and Colon Adenocarcinomas and Is Involved in the Antitumor Action of L-733,060 and the Mitogenic Action of Substance P on Human Gastrointestinal Cancer Cell Lines

Background/Aims: It has been demonstrated that substance P (SP) and neurokinin-1 (NK-1) receptor antagonist L-733,060 induces cell proliferation and inhibition, respectively, in several human cancer cell lines. At present, it is unknown whether such actions are exerted on human gastric and colon adenocarcinomas. We carried out an in vitro study of the growth-inhibitory capacity of L-733,060 against human gastric and colon adenocarcinomas. Methods: A coulter counter was used to determine viable cell numbers followed by application of the tetrazolium compound MTS. Immunoblot analysis was used to determine the NK-1 receptors and the DAPI method was applied to demonstrate apoptosis. Immunohistochemistry was used to demonstrate NK-1 receptors in primary human gastric and colon adenocarcinomas. Results: We observed the presence of several NK-1 receptor isoforms in human gastric and colon adenocarcinomas. Nanomolar concentrations of SP increased the growth of both cell lines and micromolar concentrations of L-733,060 inhibited the growth of such cell lines, with and without previous administration of SP. L-733,060 inhibited the growth of the 23132/87 and SW-403 cell lines in a dose-dependent manner. After administration of L-733,060, apoptosis was observed in both cell lines. In both human primary gastric and colon adenocarcinomas, a high density of NK-1 receptors was observed. Immunoreactivity, showing a diffuse cytoplasmic staining, was observed in the epithelial cells of normal and tumor glands and in numerous stromal elements. Conclusions: We demonstrated that NK-1 receptors were expressed in 23132/37 and SW-403 cell lines and in human primary gastric and colon adenocarcinomas, that SP is a mitogen and that the antitumor action of L-733,060 on both human cell lines occurs through the NK-1 receptor. Data also indicate that the cell death observed is produced by apoptosis. These data suggest that the NK-1 receptor is a new and promising target in the treatment of human gastrointestinal adenocarcinomas.

The NK-1 receptor is expressed in human melanoma and is involved in the antitumor action of the NK-1 receptor antagonist aprepitant on melanoma cell lines

Melanoma, the most deadly form of skin cancer, is aggressive and resistant to current therapies. It has been previously reported that the substance P and neurokinin-1 (NK-1) receptor antagonists induce cell proliferation and cell inhibition, respectively, in human melanoma cell lines. Aprepitant is a selective high-affinity antagonist of the human NK-1 receptor. Until now, this drug has been used as an anxiolytic, antidepressant and antiemetic. Moreover, the antitumor action of aprepitant has been previously reported. However, the presence of NK-1 receptors in human melanomas and whether the antitumor action of the NK-1 receptor antagonist aprepitant is exerted on human malignant melanomas have not been previously described. The aims of this study are to show the presence of NK-1 receptors in human malignant melanomas and the antitumoral action of aprepitant against several human melanoma cell lines. Immunoblot analysis was used to determine the presence of NK-1 receptors in human melanoma cell lines, and immunohistochemistry was used to demonstrate NK-1 receptors in human melanoma samples. We performed an in vitro study of the cytotoxicity of the NK-1 receptor antagonist aprepitant on human melanoma cell lines. A coulter counter was used to determine viable cell numbers, followed by application of the tetrazolium compound MTS. The DAPI method was applied to demonstrate apoptosis. We observed that NK-1 receptors were present in all the melanoma samples studied as well as in human melanoma cell lines. We also showed that melanoma cell lines expressed mRNA for the NK-1 receptor. Moreover, after using a knockdown method, we showed that NK-1 receptors are involved in the viability of tumor cells. In this study, we also report that aprepitant, at 10–60 μM concentrations, elicits cell growth inhibition in a concentration-dependent manner in all melanoma cell lines studied, that the specific antitumor action of aprepitant occurs through the NK-1 receptor and that melanoma cell death is due to apoptosis. These findings show for the first time that the NK-1 receptor may be a promising new target and that the NK-1 receptor antagonist aprepitant could be a candidate as a new antitumor drug in the treatment of human melanoma.

Chryseobacterium indologenes infection in a newborn: a case report

IntroductionChryseobacterium indologenes is an uncommon human pathogen. Most infections have been detected in hospitalized patients with severe underlying diseases who had indwelling devices implanted. Infection caused by C. indologenes in a newborn has not been previously reported.Case presentationWe present a case of ventilator-associated pneumonia caused by C. indologenes in a full-term Caucasian newborn baby boy with congenital heart disease who was successfully treated with piperacillin-tazobactam.ConclusionC. indologenes should be considered as a potential pathogen in newborns in the presence of invasive equipment or treatment with long-term broad-spectrum antibiotics. Appropriate choice of effective antimicrobial agents for treatment is difficult because of the unpredictability and breadth of antimicrobial resistance of these organisms, which often involves resistance to many of the antibiotics chosen empirically for serious Gram-negative infections.

The NK-1 Receptor: A New Target in Cancer Therapy

After binding to the specific neurokinin-1 (NK-1) receptor, the peptide substance P (SP), which is widely distributed in both the central and peripheral nervous systems, induces tumor cell proliferation, angiogenesis, and migration of the tumor cells for invasion and metastasis. However, after binding to NK-1 receptors, NK-1 receptor antagonists inhibit the three above mechanisms. In fact, the antiproliferative action exerted by NK-1 receptor antagonists is because they induce cancer cells to die by apoptosis, whereas SP exerts an antiapoptotic effect. Moreover, it is known that NK-1 receptors are overexpressed in tumors and that tumor cells express several isoforms of the NK-1 receptor. All these data suggest that the SP/NK-1 receptor system could play an important role in the development of cancer; that SP may be a universal mitogen in NK-1 receptor-expressing tumor cells, and that NK-1 receptor antagonists could offer a promising therapeutic strategy for the treatment of human cancer, since they act as broad-spectrum antitumor agents. In sum, the NK-1 receptor may be a new and promising target in the treatment of human cancer.

The Role of Neurokinin-1 Receptor in the Microenvironment of Inflammation and Cancer

The recent years have witnessed an exponential increase in cancer research, leading to a considerable investment in the field. However, with few exceptions, this effort has not yet translated into a better overall prognosis for patients with cancer, and the search for new drug targets continues. After binding to the specific neurokinin-1 (NK-1) receptor, the peptide substance P (SP), which is widely distributed in both the central and peripheral nervous systems, triggers a wide variety of functions. Antagonists against the NK-1 receptor are safe clinical drugs that are known to have anti-inflammatory, analgesic, anxiolytic, antidepressant, and antiemetic effects. Recently, it has become apparent that SP can induce tumor cell proliferation, angiogenesis, and migration via the NK-1 receptor, and that the SP/NK-1 receptor complex is an integral part of the microenvironment of inflammation and cancer. Therefore, the use of NK-1 receptor antagonists as a novel and promising approach for treating patients with cancer is currently under intense investigation. In this paper, we evaluate the recent scientific developments regarding this receptor system, its role in the microenvironment of inflammation and cancer, and its potentials and pitfalls for the usage as part of modern anticancer strategies.

The substance P/neurokinin-1 receptor system in lung cancer: focus on the antitumor action of neurokinin-1 receptor antagonists.

The last decades have seen no significant progress in extending the survival of lung cancer patients and there is an urgent need to improve current therapies. The substance P (SP)/neurokinin-1 receptor (NK-1R) system plays an important role in the development of cancer: SP and NK-1R antagonists respectively induce cell proliferation and inhibition in human cancer cell lines. No study of the involvement of this system in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cells has been carried out in depth. Here, we demonstrate the involvement of the SP/NK-1R system in human H-69 (SCLC) and COR-L23 (NSCLC) cell lines: (1) they express isoforms of the NK-1R and mRNA for the NK-1R; (2) they overexpress the tachykinin 1 gene; (3) the NK-1R is involved in their viability; (4) SP induces their proliferation; (5) NK-1R antagonists (Aprepitant (Emend), L-733,060, L-732,138) inhibit the growth of both cell lines in a concentration-dependent manner; (6) the specific antitumor action of these antagonists against such cells occurs through the NK-1R; and (7) lung cancer cell death is due to apoptosis. We also demonstrate the presence of NK-1Rs and SP in all the human SCLC and NSCLC samples studied. Our findings indicate that the NK-1R may be a promising new target in the treatment of lung cancer and that NK-1R antagonists could be new candidate antitumor drugs in the treatment of SCLC and NSCLC.

Paravertebral anesthesia: how substance P and the NK-1 receptor could be involved in regional block and breast cancer recurrence.

In a retrospective study, Exadaktylos et al. [1] reported a beneficial relationship between paravertebral block and cancer recurrence in women undergoing mastectomy and axillary clearance for breast cancer. In fact, these authors concluded that ‘‘breast cancer patients undergoing surgery with paravertebral anesthesia and analgesia combined with general anesthesia have a lower incidence of cancer recurrence or metastasis during the initial years of followup than patients undergoing surgery with general anesthesia and patient-controlled morphine analgesia’’ [1]. These authors speculated that regional anesthesia might attenuate the perioperative factors that enhance tumor growth and spreading [1]. In this sense, regional anesthesia may help to maintain normal perioperative immune function by attenuating the surgical stress response by blocking noxious inputs mediated by substance P [2]. It is known that the stress response induces an inhibition of the immune function (i.e., there is a marked attenuation of natural killer cells, these cells being involved in preventing tumor dissemination) [3]. Paravertebral anesthesia also spares patients from postoperative opioids (e.g., morphine), which inhibit both cellular and humoral immune function [4, 5]; in addition, it is known that morphine exerts a proangiogenic effect [6]. In sum, the authors surmised that regional anesthesia and analgesia may help to preserve immune function by attenuating the surgical stress response and diminishing the need for opioids. However, until now the underlying mechanisms remain unknown. The reason for this letter is to provide additional data that could support and explain the relationship between regional anesthesia, analgesia, and the recurrence of cancer. Many reports have clearly established an overexpression of neurokinin-1 (NK-1) receptors in tumor cells and others have reported the roles in which substance P (SP) is involved [7]. Summing up these investigations, it could be stated that:

Antitumor activity of neurokinin-1 receptor antagonists in MG-63 human osteosarcoma xenografts

Osteosarcoma is a highly malignant bone tumor in children and adolescents. Aprepitant is a selective high‑affinity antagonist of the human neurokinin‑1 (NK‑1) receptor (NK1R) with robust antitumor activity. No data exist on the presence of NK1R in osteosarcoma and whether this tumor responds to NK1R antagonists. Here, we analyzed the expression of NK1R in the human osteosarcoma cell line MG-63 with western blot analysis and PCR and found significant expression both at the protein and mRNA levels. We further studied the growth inhibitory capacity of aprepitant and other NK1R antagonists on MG-63 in vitro using an MTS cytotoxicity assay and DAPI staining. All antagonists induced tumor growth inhibition and apoptosis. Synergism was observed for the combination of L-733,060 with common cytostatic drugs in MG-63, but not in non-malignant HEK293 cells. Pretreatment of HEK293 with L-733,060 prior to exposure to cytostatic drugs partially protected HEK293 cells from inhibition by these drugs. Furthermore, nanomolar concentrations of substance P (SP), the natural ligand of the NK1R, increased the growth rate of MG‑63 cells and micromolar concentrations of aprepitant inhibited SP-induced growth in a dose‑dependent manner. In vivo, a xenograft for MG-63 was created in nude mice and treated with peritumoral s.c. injections of fosaprepitant, which resulted in a significant reduction of tumor volume. Collectively, we demonstrated for the first time that the NK1R is expressed in human osteosarcoma cell line MG‑63 and that this receptor can be targeted with NK1R antagonists both in vitro as well as in vivo.

Successful treatment of Stenotrophomonas maltophilia meningitis in a preterm baby boy: a case report

IntroductionStenotrophomonas maltophilia is an important cause of hospital acquired infection particularly among severely debilitated and immunosuppressed patients.Case presentationWe report a case of S. maltophilia meningitis in a preterm baby boy after a neurosurgical procedure, successfully treated with trimethoprim-sulfamethoxazole and ciprofloxacin.ConclusionThis organism should be considered as a potential cause of meningitis and trimethoprim-sulfamethoxazole and ciprofloxacin are a combination that is successful and safe for treating preterm infants.

Immunolocalization of NK-1 Receptor and Substance P in Human Normal Placenta

A role for Substance P (SP) in human placenta is not known, although is possible that regulates placental physiology through the Neurokinin (NK)-1 receptor. Ten human normal placenta tissues were studied by immunohistochemistry to demonstrate the localization of NK-1 receptor and SP. An immunostaining pattern for NK-1 receptor and SP was observed in the endothelium and myocytes of fetal blood vessels, decidua and trophoblast. The SP is located in both the cytoplasm and the nucleus whereas NK-1 receptor in cytoplasmic. These findings reported here for the fist time, suggest a role for the SP and NK-1 receptor in the placental physiology.