Abstract. BACKGROUND:Breast cancer is the most common cancer affecting women in the world today. Matrix metalloproteinases (MMPs) are a family of endopeptidases that can degrade extracellular matrix proteins and promote cell invasion and metastasis. MMPs are differentially expressed and their expressions are often associated with a poor prognosis for patients. OBJECTIVE: The aim of this study is to investigate and compare the expression of MMPs in different grades of human breast cancer tissues with normal breast tissues. PATIENTS AND METHODS: We collected 39 breast cancer samples (24 grade II and 15 grade III) along with 16 normal breast tissues from outside the tumor margin during cancer removal surgery. The samples were analysed for the expression of all known MMPs using real-time quantitative PCR. RESULTS:The results indicate that mRNA expressions of MMP-1, -9,-11,-15,-24 and -25 were upregulated in breast cancer tissues when compared to normal breast tissues. But, the mRNA expressions of MMP-10 and MMP-19 were downregulated in cancer tissue. In membrane associated MMPs like MMP-15 and MMP-24 we found a grade dependent increase of their mRNA expression.CONCLUSION: Our studies demonstrate that MMPs are differentially regulated in breast cancer tissues and they might play various roles in tumor invasion, metastasis and angiogenesis. Thus, MMPs are of immense value to be studied as diagnostic markers and drug target.

Di-(2-ethylhexyl) phthalate (DEHP) is the most common plasticizer used in polyvinyl chloride-based plastics. DEHP is not covalently bound to the plastics and is easily released to the environment, resulting in human exposure. In this study, the adult rats were exposed to DEHP and its effects on the uterus was evaluated. Healthy adult female rats were treated with DEHP orally (with dose level 0, 1, 10, and 100 mg/kg body weight/day) for 30 days. No significant changes in the body weight and wet uterine weight were observed. Ovarian hormones and their receptor levels in the uterus were increased. Histological studies exhibited the structural abnormalities such as decrease in diameter, thinning of the layers and disruption in the glandular epithelium.

Neuroblastoma (NB) is the most common cancer of infancy and accounts for nearly one tenth of pediatric cancer deaths. This mortality rate has been attributed to the > 50% frequency of relapse despite intensive, multimodal clinical therapy in patients with progressive NB. Given the disease's heterogeneity and developed resistance, attaining a cure after relapse of progressive NB is highly challenging. A rapid decrease in the timeline between successive recurrences is likely due to the ongoing acquisition of genetic rearrangements in undifferentiated NB-cancer stem cells (CSCs). In this review, we present the current understanding of NB-CSCs, their intrinsic role in tumorigenesis, their function in disease progression, and their influence on acquired therapy resistance and tumor evolution. In particular, this review focus on the intrinsic involvement of stem cells and signaling in the genesis of NB, the function of pre-existing CSCs in NB progression and therapy response, the formation and influence of induced CSCs (iCSCs) in drug resistance and tumor evolution, and the development of a CSC-targeted therapeutic approach.

Neuroblastoma (NB) deriving from neural crest cells is the most common extra-cranial solid cancer at infancy. NB originates within the peripheral sympathetic ganglia in adrenal medulla and along the midline of the body. Clinically, NB exhibits significant heterogeneity stretching from spontaneous regression to rapid progression to therapy resistance. MicroRNAs (miRNAs, miRs) are small (19-22 nt in length) non-coding RNAs that regulate human gene expression at the post-transcriptional level and are known to regulate cellular signaling, growth, differentiation, death, stemness, and maintenance. Consequently, the function of miRs in tumorigenesis, progression and resistance is of utmost importance for the understanding of dysfunctional cellular pathways that lead to disease evolution, therapy resistance, and poor clinical outcomes. Over the last two decades, much attention has been devoted to understanding the functional roles of miRs in NB biology. This review focuses on highlighting the important implications of miRs within the context of NB disease progression, particularly miRs' influences on NB disease evolution and therapy resistance. In this review, we discuss the functions of both the "oncomiRs" and "tumor suppressor miRs" in NB progression/therapy resistance. These are the critical components to be considered during the development of novel miR-based therapeutic strategies to counter therapy resistance.