Case report and literature review: primary cutaneous carcinosarcoma

Carcinosarcomas are rare but aggressive neoplasms commonly described in organs such as the breast, urinary bladder, uterus, liver, and lungs. Histopathologically, they are characterized by the presence of malignant epithelial and mesenchymal components. The exact histogenesis of carcinosarcomas remains unknown and is debated in the literature. Primary carcinosarcomas of the skin are uncommon. To our knowledge, 20 cases of primary cutaneous carcinosarcoma have been described in the world literature. Most of these tumors were seen on the head and neck region of older individuals, both male and female. Microscopically, the more common carcinoma component is a squamous cell carcinoma followed by basal cell carcinoma, whereas the most common sarcoma component is an osteosarcoma. We report an example of this rare entity and speculate on its histogenesis in the skin.     

Genotype characterization and phylogenetic analysis of hepatitis B virus isolates from Iranian patients

Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions.     

Human chondrocytes differentially express matrix modulators during in vitro expansion for tissue engineering

Cartilage tissue engineering plays an important role in the generation of grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Dedifferentiated cells produce matrix of less quality, and the molecular basis is still not well understood. Therefore, the aim of our study was to investigate the expression of matrix modulators in human chondrocytes during expansion. Human chondrocytes were isolated from septal cartilage (n=32) and held in primary cell culture. Cells were harvested after 1, 6 and 21 days. The differentiation of cells using light microscopy, the expression patterns of various proteins (MMPs, BMPs, and TIMPs) using immunohistochemistry, and the expression of distinct genes using microarray technique, were investigated. The chondrocytes showed strong in vitro proliferation. After 6 and 21 days, BMP-5 and -8 were up-regulated, BMP-2 was down-regulated and BMP-6 was inactivated. Other BMPs were not expressed. The expression of MMP-2, -3 and -13 was up-regulated from day 1 to 21, and MMP-12 and -20 were down-regulated. Other MMPs were not expressed. TIMP-1 was up-regulated and TIMP-3 was down-regulated during expansion. Differential expression of matrix modulators might influence the matrix composition of engineered cartilage. Improving the basic knowledge in this area may ultimately help clinicians to identify and proactively intervene in an attempt to prevent bioartificial cartilage from losing stability.     

Effect of vascular cell adhesion molecule 1 on fibroblasts in human eosinophilic chronic rhinosinusitis

The pathogenesis of eosinophilic chronic rhinosinusitis (ECRS) is still unclear. Paranasal mucosa inflammation is thought to be related to eosinophilic infiltration. This infiltration seems to induce changes in the expression of cell adhesion molecules such as vascular cell adhesion molecule 1 (VCAM-1). The E-cadherin-beta-catenin complex maintains the integrity of the epithelium. Downregulation of beta-catenin and E-cadherin is a pivotal factor for progressive cell growth. This study aimed to assess which cytokines regulate the expression of the adhesion molecule E-cadherin and the multi-functional protein beta-catenin, which plays a key role in cadherin-mediated anchoring in ECRS. Cultured ECRS specimens were incubated with human VCAM-1. After a period of up to 72 h, expression of E-cadherin and beta-catenin was determined using cytokine immunoassay and immunohistochemistry. In ECRS, significant increases in E-cadherin expression were found in fibroblast cell cultures. Stimulation with VCAM-1 did not produce a significant alteration in the expression of the adherens junction protein beta-catenin. In addition, VCAM-1 did not decrease the levels of membrane staining for adherens junction proteins. The selective increase in E-cadherin expression in eosinophilic fibroblast cultures might be explained by a higher concentration of the Th2-type cytokines in these cultures. The tissue remodelling observed during chronic eosinophilic inflammation offers new insight into the pathogenesis of ECRS.     

The calcium-activated chloride channel anoctamin 1 acts as a heat sensor in nociceptive neurons

Nociceptors are a subset of small primary afferent neurons that respond to noxious chemical, thermal and mechanical stimuli. Ion channels in nociceptors respond differently to noxious stimuli and generate electrical signals in different ways. Anoctamin 1 (ANO1 also known as TMEM16A) is a Ca(2+)-activated chloride channel that is essential for numerous physiological functions. We found that ANO1 was activated by temperatures over 44 °C with steep heat sensitivity. ANO1 was expressed in small sensory neurons and was highly colocalized with nociceptor markers, which suggests that it may be involved in nociception. Application of heat ramps to dorsal root ganglion (DRG) neurons elicited robust ANO1-dependent depolarization. Furthermore, knockdown or deletion of ANO1 in DRG neurons substantially reduced nociceptive behavior in thermal pain models. These results indicate that ANO1 is a heat sensor that detects nociceptive thermal stimuli in sensory neurons and possibly mediates nociception.     

Predator and restraint stress during gestation facilitates pilocarpine-induced seizures in prepubertal rats

Stress during gestation can result in early and long-term developmental aberrations. This study aimed to assess the impact of prenatal restraint or predator stress on pilocarpine-induced epileptic behavior. Pregnant rats were exposed to stressors on gestational days 15, 16, and 17. Restraint stress consisted of daily restraint of the dam. During predator stress, caged rats were exposed to a cat in a cage. On postnatal day 25, male pups were injected with pilocarpine and the behavior of each rat was observed. Prenatal stress led to low birth weight and increased blood corticosterone levels. Both stressors significantly potentiated pilocarpine-induced seizures. Predator-stressed pups exhibited significantly severe tonic-clonic seizures compared with restraint-stressed animals. These data emphasize the impact of prenatal stress on fetal growth, and neural and endocrine function. The results also suggest that psychosocial stressors have a greater impact on neural and endocrine function than physical stressors do.     

Signaling for lymphangiogenesis via VEGFR-3 is required for the early events of metastasis

Metastasis to regional lymph nodes is an important and early event in many tumors. Vascular endothelial growth factor-C (VEGF-C), VEGF-D and their receptor VEGFR-3, play a role in tumor spread via the lymphatics, although the timing of their involvement is not understood. In contrast, VEGFR-2, activated by VEGF-A, VEGF-C and VEGF-D, is a mediator of angiogenesis and drives primary tumor growth. We demonstrate the critical role for VEGFR-3, but not VEGFR-2, in the early events of metastasis. In a tumor model exhibiting both VEGF-D-dependent angiogenesis and lymphangiogenesis, an antibody to VEGFR-2 (DC101) was capable of inhibiting angiogenesis (79 % reduction in PECAM + blood vessels) and growth (93 % reduction in tumor volume). However, unlike an anti-VEGFR-3 Mab (mF4-31C1), DC101 was not capable of eliminating either tumor lymphangiogenesis or lymphogenous metastasis (60 % reduction of lymph node metastasis by DC101 vs 95 % by mF4-31C1). Early excision of the primary tumors demonstrated that VEGF-D-mediated tumor spread precedes angiogenesis-induced growth. Small but highly metastatic primary human breast cancers had significantly higher lymphatic vessel density (23.1 vessels/mm²) than size-matched (11.7) or larger non-metastatic tumors (12.4) thus supporting the importance of lymphatic vessels, as opposed to angiogenesis-mediated primary tumor growth, for nodal metastasis. These results suggest that lymphangiogenesis via VEGF-D is more critical than angiogenesis for nodal metastasis.     

The Production and Characterization of Novel Heavy-Chain Antibodies Against the Tandem Repeat Region of MUC1 Mucin

Camelidae are known to produce immunoglobulins (Igs) devoid of light chains and constant heavy-chain domains (CH₁). Antigen-specific fragments of these heavy-chain IgGs (VHH) are of great interest in biotechnology applications. This paper describes the first example of successfully raised heavy-chain antibodies in Camelus dromedarius (single-humped camel) and Camelus bactrianus (two-humped camel) against a MUC1 related peptide that is found to be an important epitope expressed in cancerous tissue. Camels were immunized against a synthetic peptide corresponding to the tandem repeat region of MUC1 mucin and cancerous tissue preparation obtained from patients suffering from breast carcinoma. Three IgG subclasses with different binding properties to protein A and G were purified by affinity chromatography. Both conventional and heavy-chain IgG antibodies were produced in response to MUC1-related peptide. The elicited antibodies could react specifically with the tandem repeat region of MUC1 mucin in an enzyme linked immunosorbant assay (ELISA). Anti-peptide antibodies were purified after passing antiserum over two affinity chromatography columns. Using ELISA, immunocytochemistry and Western blotting, the interaction of purified antibodies with different antigens was evaluated. The antibodies were observed to be selectively bound to antigens namely: MUC1 peptide (tandem repeat region), human milk fat globule membrane (HMFG), deglycosylated human milk fat globule membrane (D-HMFG), homogenized cancerous breast tissue and a native MUC1 purified from ascitic fluid. K_a values of specific polyclonal anti-peptide antibodies were estimated in C. dromedarius and C. bactrianus, as 7 × 10¹⁰ M^{? 1} and 1.4 × 10¹⁰ M^{? 1} respectively.     

Tumor location and nature of lymphatic vessels are key determinants of cancer metastasis

Tumor metastasis to lymph nodes is a key indicator of patient survival, and is enhanced by the neo-lymphatics induced by tumor-secreted VEGF-C or VEGF-D, acting via VEGFR-3 signalling. These targets constitute important avenues for anti-metastatic treatment. Despite this new understanding, clinical observations linking metastasis with tumor depth or location suggest that lymphangiogenic growth factors are not the sole determinants of metastasis. Here we explored the influence of tumor proximity to lymphatics capable of responding to growth factors on nodal metastasis in a murine VEGF-D over-expression tumor model. We found that primary tumor location profoundly influenced VEGF-D-mediated lymph node metastasis: 89 % of tumors associated with the flank skin metastasised, in contrast with only 19 % of tumors located more deeply on the body wall (p < 0.01). Lymphatics in metastatic tumors arose from small lymphatics, and displayed distinct molecular and morphological profiles compared with those found in normal lymphatics. Smaller lymphatic subtypes were more abundant in skin (2.5-fold, p < 0.01) than in body wall, providing a richer source of lymphatics for VEGF-D⁺ skin tumors, a phenomenon also confirmed in human samples. This study shows that the proximity of a VEGF-D⁺ primary tumor to small lymphatics is an important determinant of metastasis. These observations may explain why tumor location relative to the lymphatic network is prognostically important for some human cancers.