Introduction. It is an example of tendon to bone healing of rotator cuff tears. Low Level Laser Therapy (LLLT) is used in pain literature, pain
Cancer associated bone pain (CIBP) is a common event in patients with advanced disease with bone metastases (BM), significantly impairing their quality of life. Treatment options are limited and mainly based on the use of opioids with unacceptable side effects. Local acidosis is a well-known cause of pain since it directly stimulates nociceptors that express acid-sensing ion channels and densely innervate bone. In BM, local acidosis derives from osteoclast bone resorption activity and from the acidification by glycolytic tumor cells. Here we speculated that the pH lowering of intratumoral interstitial fluid also promotes nociceptors sensitization and hyperalgesia through the activation of cells of mesenchymal origin in BM microenvironment that might release inflammatory and nociceptive mediators. As a model of breast cancer that can metastatise to the bone we used MDA-MB-231 (MDA), and a subclone with a higher tendency to form osteolytic BM (bmMDA). We evaluated the basal expression of proton pumps/ion transporters by Real-Time PCR (Q-RT-PCR). To evaluate the effect of extracellular acidosis on mesenchymal tumor-associated stroma, we used human osteoblast primary cultures from healthy donors and cancer-associated fibroblasts isolated with specific immunobeads from the tumor biopsies of patient with BM. We exposed the cells to pH 6.8 medium at different time points (between 3 to 24 hours). After the short-term incubation with acidosis, for the expression of and acid-sensing ion channels, inflammatory cytokines and nociceptive mediators that can produce hyperalgesia, we used both a wide screening through a deep-sequencing approach and Q-RT-PCR, and ELISA. Xenograft for osteolytic BM induced by intratibial injection of bmMDA were treated with Omeprazole and monitored for CIBP through several cognitive tests. We found a significantly higher extracellular proton efflux and expression of proton pumps/ion transporters associated with the acid-base balance, the monocarboxylate transporter 4 (MCT4), the carbonic anhydrase (CA9), and the vacuolar ATPase (V-ATPase) V. 1. G. 1. subunit, and V. 0. c subunitin bmMDA, a subclone that is prone to form BM in respect to the parental cell line MDA-MB-231. In mesenchymal stromal cells, osteoblasts and cancer-associated fibroblasts, the incubation with pH 6.8 induced the expression of the achid-sensing ion channels AISC3/ACCN3 and AICS4/ACCN4, as well as of the nociceptive modulators nerve growth factor (NGF), Brain-derived neurotrophic factor (BDNF), and of the inflammatory cytokines interleukin 6 (IL6) and 8 (IL8), and Chemokine (C-C motif) ligand 5 (CCL5). Furthermore, the targeting of V0c subunit to inhibit intratumoral acidification significantly reduced CIBP in mice model of BM. In this study we demonstrated for the first time that, in addition to the direct acid-sensing neuronal stimulation, the acidic microenvironment of BM causes hyperalgesia through the activation of an inflammatory reaction in the tumor-associated mesenchymal stroma at the tumor site, thereby offering as a new target for
We evaluated the possible induction of a systemic immune response to increase anti-tumour activity by the re-implantation of destructive tumour tissue treated by liquid nitrogen in a murine osteosarcoma (LM8) model. The tumours were randomised to treatment by excision alone or by cryotreatment after excision. Tissue from the tumour was frozen in liquid nitrogen, thawed in distilled water and then re-implanted in the same animal. In addition, some mice received an immunological response modifier of OK-432 after treatment. We measured the levels of interferon-gamma and interleukin-12 cytokines and the cytotoxicity activity of splenocytes against murine LM8 osteosarcoma cells. The number of lung and the size of abdominal metastases were also measured. Re-implantation of tumour tissue after cryotreatment activated immune responses and inhibited metastatic tumour growth. OK-432 synergistically enhanced the anti-tumour effect. Our results suggest that the treatment of malignant bone tumours by reconstruction using autografts containing tumours which have been treated by liquid nitrogen may be of clinical value.