ObjectiveMiR-21 is an oncomir expressed by malignant cells and/or tumor microenvironment components. In this study we focused on understanding the effects of stromal miR-21 on esophageal malignant cells.DesignMiR-21 expression was evaluated in formalin-fixed paraffin-embedded samples from patients with esophageal squamous-cell carcinoma (SCC) by quantitative RT-PCR. MiR-21 tissue distribution was visualized with in situ hybridization. A co-culture system of normal fibroblasts and esophageal cancer cells was used to determine the effects of fibroblasts on miR-21 expression levels, and on SCC cell migration and invasion.ResultsMiR-21 was overexpressed in SCCs, when compared to the adjacent non-tumor tissues (P = 0.0007), and was mainly localized in the cytoplasm of stromal cells adjacent to malignant cells. Accordingly, miR-21 expression was increased in tumors with high versus low stromal content (P = 0.04). When co-cultured with normal fibroblasts, miR-21 expression was elevated in SCC cells (KYSE-30), while its expression was restricted to fibroblasts when co-cultured with adenocarcinoma cells (OE-33 and FLO-1). MiR-21 was detected in conditioned media of cancer cell lines, illustrating the release of this miRNA into the environment. Co-culturing with normal fibroblasts or addition of fibroblast conditioned media caused a significant increase in cell migration and invasion potency of KYSE-30 cells (P<0.0001). In addition, co-culturing cancer cells with fibroblasts and expression of miR-21 induced the expression of the cancer associated fibroblast (CAF) marker S100A4.ConclusionsMiR-21 expression is mostly confined to the SCC stroma and its release from fibroblasts influences the migration and invasion capacity of SCC cells. Moreover, miR-21 may be an important factor in “activating” fibroblasts to CAFs. These findings provide new insights into the role of CAFs and the extracellular matrix in tumor microenvironment formation and in tumor cell maintenance, and suggest miR-21 may contribute to cellular crosstalk in the tumor microenvironment.

The present study evaluated the efficacy of melatonin in cyclophosphamide (CP)-induced testicular injury, lipid peroxidative damage, and antioxidant enzymes status of the mice testis on the basis of biochemical and histological studies. Mice were pretreated with four different doses of melatonin (2.5, 5, 10, and, 20 mg/kg by body weight (b.w.)) via intraperitoneal injection for five consecutive days followed by injection with CP (200 mg/kg b.w.) 1 h after the last injection of melatonin on the 5th day. After 24 h, mice were euthanized, testes were immediately removed, and biochemical and histological studies were conducted. Treatment with melatonin significantly mitigates lipid peroxidation, superoxide dismutase, and catalase activity and the level of reduced glutathione content abnormality induced by CP in mice testis. Histological examination clearly demonstrates that pretreatment of melatonin prevented CP-induced spermatogenesis toxicity and spermatogenic cells reduction in mice testis. The protective effect of melatonin is likely due to the antioxidative properties of the indolamine existed in the chemical structure. Because melatonin is a safe, natural compound, it could be used concomitantly as a supplement to protect people undergoing chemotherapy against reproductive toxicity.

The preventive effect of hesperidin as a flavonoid was investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hesperidin at four different doses (50, 100, 200, and 400 mg/kg b.w.) for five consecutive days. Mice were injected intraperitoneally on the fifth day with cyclophosphamide (50 mg/kg b.w.) and killed after 24 h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/ polychromatic erythrocyte + normochromatic erythrocyte). Three last doses of hesperidin significantly reduced frequency of MnPCEs induced by cyclophosphamide (p<0.0001). Hesperdin at dose 200 mg/kg b.w. reduced MnPCEs 2.37 time and also completely normalized PCE/ (PCE+NCE) ratio. Histological examination of bone marrow showed that hesperidin affected on proliferation and hyper cellularity of immature myeloid elements in bone marrow that reduced by cyclophosphamide. It is obvious that hesperidin, may with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells.

The current study aimed to evaluate the protective effects of melatonin, a pineal secretory product, against hepatotoxicity induced by cyclophosphamide (CP) in mice. Mice were pretreated with melatonin intraperitoneally for 7 consecutive days before the administration of a single intraperitoneal dose of 200 mg/kg CP. 24 hr after CP administration, the mice were anesthetized, blood was then removed, and serum toxicity enzymes activities were evaluated. After the blood sampling, all animals were killed, livers were then removed, and histological studies were conducted. Serum toxicity marker enzymes were significantly increased after CP treatment but restored in melatonin pretreated groups. In addition, administration of CP induced necrotic hepatocyte with small crushed nuclei, portal space with severe inflammation, and hepatocytes surrounded by lymphocytic infiltration in hepatic tissues. However, melatonin effectively protected against CP-induced histopathological abnormalities in the liver tissues. Our results reveal that melatonin produces a potent hepatoprotective mechanism against CP. Therefore, melatonin could be a potent candidate to use concomitantly as a supplement agent against hepatotoxicity of CP for the patients undergoing chemotherapy.

We have analyzed the possible relevance of HPV infection for breast cancer risk among Iranian women from north part of Iran. Among women with breast cancer, 25.9% had positive test results for HPV DNA in breast tumor samples in contrast to 2.4% of women with noncancer status (P=0.002). The infection of HPV has increased the risk of breast cancer (OR 14.247; 95% CI 1.558–130.284,P=0.019). The high-risk HPV genotypes (types 16 and 18) in samples of breast cancer patients were the predominant types (53.34%). Other genotypes detected in breast cancer were HPV-6, HPV-11, HPV-15, HPV-23, and HPV-124, and one isolate could not be genotyped compared to HPV reference sequences. While the sole detected HPV in control specimens was HPV-124. Our study reveals that HPV infection and age are the risk factors in breast cancer development in the north part of Iran.