Sarcomatoid Carcinoma of the Penis.

Sarcomatoid carcinomas are biphasic tumours, which occur at any site in the human body. It rarely affects the penis, with only 38 cases being reported in literature. It may be considered as a variant of squamous cell carcinoma or a dedifferentiated tumour. We report a 60-year old gentleman who presented with a swelling in the glans penis. He underwent a partial penectomy. Histopathology revealed sarcomatoid carcinoma of the penis, which was confirmed by immunohistochemistry. The rarity of this clinical entity makes its diagnosis difficult.

Phosphotyrosine profiling identifies ephrin receptor A2 as a potential therapeutic target in esophageal squamous-cell carcinoma.

Esophageal squamous-cell carcinoma (ESCC) is one of the most common malignancies in Asia. Currently, surgical resection of early-stage tumor is the best available treatment. However, most patients present late when surgery is not an option. Data suggest that chemotherapy regimens are inadequate for clinical management of advanced cancer. Targeted therapy has emerged as one of the most promising approaches to treat several malignancies. A prerequisite for developing targeted therapy is prior knowledge of proteins and pathways that drive proliferation in malignancies. We carried out phosphotyrosine profiling across four different ESCC cell lines and compared it to non-neoplastic Het-1A cell line to identify activated tyrosine kinase signaling pathways in ESCC. A total of 278 unique phosphopeptides were identified across these cell lines. This included several tyrosine kinases and their substrates that were hyperphosphorylated in ESCC. Ephrin receptor A2 (EPHA2), a receptor tyrosine kinase, was hyperphosphorylated in all the ESCC cell lines used in the study. EPHA2 is reported to be oncogenic in several cancers and is also known to promote metastasis. Immunohistochemistry-based studies have revealed EPHA2 is overexpressed in nearly 50% of ESCC. We demonstrated EPHA2 as a potential therapeutic target in ESCC by carrying out siRNA-based knockdown studies. Knockdown of EPHA2 in ESCC cell line TE8 resulted in significant decrease in cell proliferation and invasion, suggesting it is a promising therapeutic target in ESCC that warrants further evaluation.

Identification of a novel AMPK-PEA15 axis in the anoikis-resistant growth of mammary cells.

INTRODUCTION: Matrix detachment triggers anoikis, a form of apoptosis, in most normal epithelial cells, while acquisition of anoikis resistance is a prime requisite for solid tumor growth. Of note, recent studies have revealed that a small population of normal human mammary epithelial cells (HMECs) survive in suspension and generate multicellular spheroids termed 'mammospheres'. Therefore, understanding how normal HMECs overcome anoikis may provide insights into breast cancer initiation and progression. METHODS: Primary breast tissue-derived normal HMECs were grown as adherent monolayers or mammospheres. The status of AMP-activated protein kinase (AMPK) and PEA15 signaling was investigated by immunoblotting. Pharmacological agents and an RNA interference (RNAi) approach were employed to gauge their roles in mammosphere formation. Immunoprecipitation and in vitro kinase assays were undertaken to evaluate interactions between AMPK and PEA15. In vitro sphere formation and tumor xenograft assays were performed to understand their roles in tumorigenicity. RESULTS: In this study, we show that mammosphere formation by normal HMECs is accompanied with an increase in AMPK activity. Inhibition or knockdown of AMPK impaired mammosphere formation. Concomitant with AMPK activation, we detected increased Ser116 phosphorylation of PEA15, which promotes its anti-apoptotic functions. Inhibition or knockdown of AMPK impaired PEA15 Ser116 phosphorylation and increased apoptosis. Knockdown of PEA15, or overexpression of the nonphosphorylatable S116A mutant of PEA15, also abrogated mammosphere formation. We further demonstrate that AMPK directly interacts with and phosphorylates PEA15 at Ser116 residue, thus identifying PEA15 as a novel AMPK substrate. Together, these data revealed that AMPK activation facilitates mammosphere formation by inhibition of apoptosis, at least in part, through Ser116 phosphorylation of PEA15. Since anoikis resistance plays a critical role in solid tumor growth, we investigated the relevance of these findings in the context of breast cancer. Significantly, we show that the AMPK-PEA15 axis plays an important role in the anchorage-independent growth of breast cancer cells both in vitro and in vivo. CONCLUSIONS: Our study identifies a novel AMPK-PEA15 signaling axis in the anchorage-independent growth of both normal and cancerous mammary epithelial cells, suggesting that breast cancer cells may employ mechanisms of anoikis resistance already inherent within a subset of normal HMECs. Thus, targeting the AMPK-PEA15 axis might prevent breast cancer dissemination and metastasis.

Studies on the histopathological changes in selected tissues of fish Labeo rohita exposed to phenol.

Histopathological changes in vital tissues like gills, liver and kidney in the fish Labeo rohita exposed for 8 days to sublethal (5.2 mgl(-1)) and lethal concentration (25.09 mg(-1)) of phenol were studied. The observed histopathological changes in the gills were epithelial hyperplasia with lamellar fusion, epithelial hypertrophy, edema, general necrosis, increased mucous production and degeneration of primary and secondary gill lamellae at sublethal (5.2 mg l(-1)) and degenerated primary and secondary gill lamellae, lamellar fusion and lamellar disorganization at lethal (25.09 mg l(-1)) concentration. In the liver, the changes include as: formation of number of vacuoles, enlargement of nuclei of some cells, enlarged sinusoids with numerous blood cells and atrophic areas at sublethal (5.2 mg I(-1)) concentration and nuclear and cytoplasmic degeneration and melanomacrophages aggregates at lethal (25.09 mg I(-1)) concentration. In case of kidney, the changes were: degeneration of proximal and distal convoluted tubule, vacuolation of renal interstitial tissue and deformation of the nuclear membrane of some cells at sublethal (5.2 mg l(-1)) and occlusion of tubular lumen, cloudy swelling degeneration and hyaline droplets degeneration at lethal (25.09 mg l(-1)) concentration.

Evaluation of protein expression pattern of stanniocalcin 2, insulin-like growth factor-binding protein 7, inhibin beta A and four and a half LIM domains 1 in esophageal squamous cell carcinoma.

The pathogenesis of esophageal squamous cell carcinoma (ESCC) involves both genetic and environmental factors. Previously, we have carried out gene and protein expression profiling of ESCC using DNA microarrays and mass spectrometry-based quantitative proteomics, respectively. These studies resulted in identification of several potential biomarkers of ESCC, some with known reports of differential expression in the scientific literature and others that were novel observations from our studies. We report systematic validation of selected markers from our studies on a larger cohort of cancer tissue sections by immunohistochemical labeling of tissue microarrays. We have validated expression of insulin-like growth factor-binding protein 7 (IGFBP7), stanniocalcin 2 (STC2), inhibin beta A (INHBA) and four and a half LIM domains 1 (FHL1). Immunohistochemical labeling with anti-stanniocalcin 2 antibody demonstrated its overexpression in 132/140 (94%) cases, IGFBP7 showed overexpression in 127/140 (91%) cases and overexpression of INHBA was observed in 62/105 (59%) of ESCC cases. In contrast, FHL1 expression was observed only in 12/143 (8%) of ESCC cases suggesting its possible involvement in tumor suppression. These data suggest that IGFBP7, INHBA, STC2 and FHL1 might play an important role in ESCC tumorigenesis, which can be explored in future studies. Overall, our findings open up new avenues for development of novel therapeutics and/or diagnostic approaches in ESCC.

Zinc toxicity to aminergic neurotransmitters in rat brain.

The present study was aimed to evaluate zinc toxicity to aminergic system in different areas of the brain of male albino rat, Rattus norvegicus. Zinc toxicity, evaluated as per Probit method was found to be 500 mg/kg body weight. For acute-dose studies, rats were given a single lethal dose of zinc chloride for one day only and for chronic-dose studies, the rats were administered with sub-lethal doses (1/10(th) of lethal dose) of zinc chloride every day for 90 days continuously. Various constituents of the aminergic system viz. dopamine, norepinephrine, and epinephrine and the catabolizing enzyme, monoamine oxidase (MAO) were determined in different regions of rat brain such as olfactory lobe, hippocampus, cerebellum, and pons-medulla on selected time intervals/days under acute and chronic treatment with zinc. The results revealed that while the levels of all aminergic neurotransmitters were elevated differentially in the above mentioned areas of brain, MAO activity registered nonsignificant inhibition in all brain regions under zinc toxicity. All these changes in the aminergic system were subsequently manifested in the behavior of rat exhibiting the symptoms of mild tremors, reduced locomotor activity and emotions, restlessness followed by lacrymation, salivation, etc. From these observations, it was obvious that zinc treatment caused severe perturbations in the functions of the nervous system. Restoration of the aminergic system along with behavior to the near normal levels under chronic treatment indicates the onset of detoxification mechanisms or development of tolerance to zinc toxicity in the animal which was not probably so efficient under acute treatment.

Overexpression of periostin and lumican in esophageal squamous cell carcinoma.

To identify biomarkers for early detection for esophageal squamous cell carcinoma (ESCC), we previously carried out a genome-wide gene expression profiling study using an oligonucleotide microarray platform. This analysis led to identification of several transcripts that were significantly upregulated in ESCC compared to the adjacent normal epithelium. In the current study, we performed immunohistochemical analyses of protein products for two candidates genes identified from the DNA microarray analysis, periostin (POSTN) and lumican (LUM), using tissue microarrays. Increased expression of both periostin and lumican was observed in 100% of 137 different ESCC samples arrayed on tissue microarrays. Increased expression of periostin and lumican was observed in carcinoma as well as in stromal cell in the large majority of cases. These findings suggest that these candidates can be investigated in the sera of ESCC patients using ELISA or multiple reaction monitoring (MRM) type assays to further explore their utility as biomarkers.

Phenotypic and functional characterization of human mammary stem/progenitor cells in long term culture.

BACKGROUND: Cancer stem cells exhibit close resemblance to normal stem cells in phenotype as well as function. Hence, studying normal stem cell behavior is important in understanding cancer pathogenesis. It has recently been shown that human breast stem cells can be enriched in suspension cultures as mammospheres. However, little is known about the behavior of these cells in long-term cultures. Since extensive self-renewal potential is the hallmark of stem cells, we undertook a detailed phenotypic and functional characterization of human mammospheres over long-term passages. METHODOLOGY: Single cell suspensions derived from human breast 'organoids' were seeded in ultra low attachment plates in serum free media. Resulting primary mammospheres after a week (termed T1 mammospheres) were subjected to passaging every 7th day leading to the generation of T2, T3, and T4 mammospheres. PRINCIPAL FINDINGS: We show that primary mammospheres contain a distinct side-population (SP) that displays a CD24(low)/CD44(low) phenotype, but fails to generate mammospheres. Instead, the mammosphere-initiating potential rests within the CD44(high)/CD24(low) cells, in keeping with the phenotype of breast cancer-initiating cells. In serial sphere formation assays we find that even though primary (T1) mammospheres show telomerase activity and fourth passage T4 spheres contain label-retaining cells, they fail to initiate new mammospheres beyond T5. With increasing passages, mammospheres showed an increase in smaller sized spheres, reduction in proliferation potential and sphere forming efficiency, and increased differentiation towards the myoepithelial lineage. Significantly, staining for senescence-associated beta-galactosidase activity revealed a dramatic increase in the number of senescent cells with passage, which might in part explain the inability to continuously generate mammospheres in culture. CONCLUSIONS: Thus, the self-renewal potential of human breast stem cells is exhausted within five in vitro passages of mammospheres, suggesting the need for further improvisation in culture conditions for their long-term maintenance.