Decrease in mast cells in oral squamous cell carcinoma: possible failure in the migration of these cells

It is becoming accepted that multiple cell types in stromal microenvironment are involved in tumorigenesis. In this setting, mast cells (MC) display a diversity of roles that may contribute to the defense against tumors or tumor progression. Thus, the aim of this study was to evaluate density and migration of MCs in OSCC (oral squamous cell carcinoma) and pre-malignant oral hyperkeratosis (leukoplakia) as well as their relationship with clinical and microscopic parameters. The tryptase and c-kit expression was analyzed in 38 cases of OSCC, 26 cases of leukoplakia, and 12 cases of clinically healthy oral mucosa (control) by means of immunohistochemistry. The tryptase(+) cell numbers were decreased in OSCC (P=0.0003) and leukoplakia (P=0.03) compared with control. Similar numbers of tryptase(+) cells were observed in leukoplakia and OSCC (P=0.31). The density of c-kit(+) MCs was also significantly lower in OSCC and leukoplakia in relation to control resulting in a reduced c-kit(+)/tryptase(+) relationship in OSCC (19%) in comparison with leukoplakia (59%) and control (63%). No correlation was observed between MC populations with clinical and microscopic characteristics of OSCC. Our findings suggest that the decrease in MC numbers in pre-malignant and malignant oral lesions may be related to the migration failure of these cells, possibly reflecting an important modification in the microenvironment during tumor initiation and progression.     

Dual role of CCL3/CCR1 in oral squamous cell carcinoma: implications in tumor metastasis and local host defense

Chemokines are small chemotactic cytokines that can induce the migration of leukocytes, activate inflammatory/immune responses and have recently been implicated in the regulation of tumor growth and organ-specific spread. In this setting, the macrophage inflammatory protein-1alpha (CCL3) chemokine displays a diversity of roles that may contribute to the directional migration of squamous cells into cervical lymph nodes or to the defense against tumor initiation and progression. Thus, the aim of this study was to determine, for the first time, the expression of CCL3 and their receptors, CCR1 and CCR5, by real-time polymerase chain reaction in samples obtained from oral squamous cell carcinoma (OSCC) and healthy gingival tissue (control). In addition, we investigated the immunoexpression of these molecules in neoplastic cells (parenchyma), inflammatory/immune cells (stroma) in primary OSCC and in metastatic and non-metastatic lymph node tissues. The relationship of CCL3/CCR1 with survival data was also evaluated. The analysis of mRNA expression revealed a significantly higher expression of CCL3 and CCR1 in OSCC compared with the controls (P<0.05). The expression of CCR5 was not different in the two groups. The percentages of CCL3+ and CCR1+ cells were observed to be similar in parenchyma and stroma in the OSCC without lymph node metastasis when compared with OSCC with lymph node metastasis (P>0.05). However, we observed the density of CCL3+ nodal cells to be significantly higher in metastatic lymph nodes when compared with non-metastatic lymph nodes in the same patients (P<0.05). Considering CCL3 in stroma, the mean survival rate for patients with high CCL3+ cell percentage was better than for those with low CCL3+ cell percentage. Our findings suggest that the CCL3/CCR1 axis may have a role in the spread of tumoral cells to the lymph nodes and also in the local host defense against the tumor.     

CXCR2 is critical for bacterial control and development of joint damage and pain in Staphylococcus aureus‐induced septic arthritis in mouse

Staphylococcus aureus is the main pathogen associated with septic arthritis. Upon infection, neutrophils are quickly recruited to the joint by different chemoattractants, especially CXCR1/2 binding chemokines. Although their excessive accumulation is associated with intense pain and permanent articular damage, neutrophils have an important function in controlling bacterial burden. This work aimed to study the role of CXCR2 in the control of infection, hypernociception and tissue damage in S. aureus‐induced septic arthritis in mice. The kinetics of neutrophil recruitment correlated with the bacterial load recovered from inflamed joint after intra‐articular injection of S. aureus. Treatment of mice from the start of infection with the non‐competitive antagonist of CXCR1/2, DF2156A, reduced neutrophil accumulation, cytokine production in the tissue, joint hypernociception and articular damage. However, early DF2156A treatment increased the bacterial load locally. CXCR2 was important for neutrophil activation and clearance of bacteria in vitro and in vivo. Start of treatment with DF2156A 3 days after infection prevented increase in bacterial load and reduced the hypernociception in the following days, but did not improve tissue damage. In conclusion, treatment with DF2156A seems be effective in controlling tissue inflammation and dysfunction but its effects are highly dependent on the timing of the treatment start.     

Overexpression of immunomodulatory mediators in oral precancerous lesions

Human leukocyte antigen (HLA) G and E, programmed cell death 1 ligand 1 (PD-L1), IL-10 and TGF-β are proteins involved in failure of the antitumor immune response. We investigated the expression of these immunomodulatory mediators in oral precancerous lesions (oral leukoplakia-OL; n = 80) and whether these molecules were related to the risk of malignant transformation. Samples of normal mucosa (n = 20) and oral squamous cells carcinoma (OSCC, n = 20) were included as controls. Tissue and saliva samples were analyzed by immunohistochemistry and ELISA respectively. Fifteen OL samples showed severe dysplasia (18.7%) and 40 samples (50%) presented combined high Ki-67/p53. Irrespective of the degree of epithelial dysplasia and the proliferation/apoptosis index of OL, the expression of HLA-G, -E, PD-L1, IL-10, TGF-β2 and -β3 was higher to control (P < 0.05) and similar to OSCC (P > 0.05). The number of granzyme B⁺ cells in OL was similar to control (P = 0.28) and lower compared to OSCC (P < 0.01). Salivary concentrations of sHLA-G, IL-10 and TGF-β did not allow for a distinction between OL and healthy individuals. Overexpression of immunosuppressive mediators in the OL reflects the immune evasion potential of this lesion, which is apparently independent of at cytological and proliferation/apoptosis status.     

Multiple hyperdontia: Report of an unusual case

Supernumerary teeth are an infrequent developmental anomaly that can appear in any area of the dental arch and can affect any dental organ. Multiple supernumerary teeth, or hyperdontia, is rare in people with no other associated diseases or syndromes. Conditions commonly associated with hyperdontia include cleft lip and palate, trichorhinophalangeal syndrome, cleidocranial dysplasia, and Gardner's syndrome. A black girl, aged 11 years 8 months, came for consultation; radiographs showed 81 teeth: 18 deciduous, 32 permanent, and 31 supernumerary. The main concern initially was to determine whether she was syndromic, and she was referred to a geneticist. G banding analysis showed pericentric inversion of chromosome 9; the chromosome formula was 46, XX, inv (9) (p13q21). Orthodontic treatment for this patient will be a clinical challenge because of the great number of teeth to be extracted and the alterations in the shapes of the teeth. Treatment goals should be established by a multidisciplinary team, where oral surgeon, orthodontist, periodontist, and prosthodontist come together to solve a medical and dental puzzle, eliminating the pieces that do not fit and searching for new ones to obtain an occlusion that will give the patient physiologic conditions of normality and esthetic satisfaction.     

Platelet-activating factor receptor plays a role in the pathogenesis of graft-versus-host disease by regulating leukocyte recruitment, tissue injury, and lethality

PAF is a potent lipid mediator involved in several manifestations of acute inflammation, including leukocyte influx, leukocyte interaction with endothelium, and production of inflammatory cytokines. The present study evaluated the relevance of PAFR for the pathogenesis of acute GVHD using a model of adoptive transfer of splenocytes from WT or PAFR(-/-) C57BL/6J to B6D2F1 mice. Mice, which received PAFR(-/-) splenocytes or treatment with the PAFR antagonist, showed reduced clinical signs of disease and no mortality. In GVHD mice receiving PAFR(-/-) splenocytes, there was deceased bacterial translocation and tissue injury. Furthermore, production of proinflammatory cytokines and chemokines (TNF-α, IFN-γ, CCL2, CCL3, and CCL5) and accumulation of CD8(+) cells in intestine and liver were reduced in mice transplanted with the PAFR(-/-) splenocyte. Mechanistically, an absence or pharmacological blockade of PAFR was associated with decreased rolling and adhesion of leukocytes to the mesenteric microcirculation, as assessed by intravital microscopy. Despite decreased GVHD, there was maintained GVL activity when PAFR(-/-) leukocytes were transferred into WT mice. In conclusion, PAFR on donor leukocytes plays a critical role in GVHD by mediating leukocyte influx and cytokine production in target tissues. PAFR antagonist may potentially be useful in the treatment of GVHD in bone marrow-transplanted patients.