Publications by authors named "Shahram Khosravi"

Intratumoral androgen biosynthesis contributes to castration-resistant prostate cancer progression in patients treated with androgen deprivation therapy. The molecular mechanisms by which castration-resistant prostate cancer acquires the capacity for androgen biosynthesis to bypass androgen deprivation therapy are not entirely known. Here, we show that semaphorin 3C, a secreted signaling protein that is highly expressed in castration-resistant prostate cancer, can promote steroidogenesis by altering the expression profile of key steroidogenic enzymes.

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Growth factor receptor tyrosine kinase (RTK) pathway activation is a key mechanism for mediating cancer growth, survival, and treatment resistance. Cognate ligands play crucial roles in autocrine or paracrine stimulation of these RTK pathways. Here, we show SEMA3C drives activation of multiple RTKs including EGFR, ErbB2, and MET in a cognate ligand-independent manner via Plexin B1.

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Prostate cancer (PCa) is among the most commonly-occurring cancers worldwide and a leader in cancer-related deaths. Local non-invasive PCa is highly treatable but limited treatment options exist for those with locally-advanced and metastatic forms of the disease underscoring the need to identify mechanisms mediating PCa progression. The semaphorins are a large grouping of membrane-associated or secreted signalling proteins whose normal roles reside in embryogenesis and neuronal development.

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The androgen receptor (AR) is a member of the nuclear receptor superfamily of transcription factors and is central to prostate cancer (PCa) progression. Ligand-activated AR engages androgen response elements (AREs) at androgen-responsive genes to drive the expression of gene batteries involved in cell proliferation and cell fate. Understanding the transcriptional targets of the AR has become critical in apprehending the mechanisms driving treatment-resistant stages of PCa.

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Eukaryotic translation initiation factor 5A2 (EIF5A2) expression is upregulated in various cancers. The present authors previously demonstrated that cytoplasmic EIF5A2 expression increases with melanoma progression and inversely correlates with patient survival. Other studies have suggested that nuclear EIF5A2 may also play a role in oncogenesis.

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Human cutaneous melanoma is a devastating skin cancer because of its invasive nature and high metastatic potential. We used tissue microarray to study the role of human eukaryotic translation initiation factor 4E (eIF4E) in melanoma progression in 448 melanocytic lesions and found that high eIF4E expression was significantly increased in primary melanomas compared with dysplastic nevi (P<0.001), and further increased in metastatic melanomas (P<0.

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Angiogenesis is associated with the tissue changes underlying chronic overuse tendinopathy. We hypothesized that repetitive, cyclic loading of human tendon cells would lead to increased expression and activity of angiogenic factors. We subjected isolated human tendon cells to overuse tensile loading using an in vitro model (1 Hz, 10% equibiaxial strain).

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Deleted in Liver Cancer-1 (DLC1) is a Rho-GTPase-activating protein known to be downregulated and function as a tumor suppressor in numerous solid and hematological cancers. Its expression status in melanoma is currently unknown however, prompting us to examine this. Using immunohistochemistry and tissue microarrays containing a large set of melanocytic lesions (n=539), we examined the expression profile of DLC1 in melanoma progression, as well as the association between DLC1 and patient survival.

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Background: C-terminal tensin-like protein (Cten) is a focal adhesion protein originally identified as a tumor suppressor in prostate cancer. It has since been found to be overexpressed and function as an oncogene in numerous other cancers, but the expression status of Cten in melanoma is still unknown.

Methods: Using tissue microarrays containing 562 melanocytic lesions, we evaluated Cten protein expression by immunohistochemistry.

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The E3 ligase Rad18 is a key regulator for the lesion bypass pathway, which plays an important role in genomic stability. However, the status of Rad18 expression in melanoma is not known. Using melanoma tissue microarray (TMA), we showed that nuclear Rad18 expression was upregulated in primary and metastatic melanoma compared to dysplastic nevi.

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Cadherin-like protein 22 (CDH22) is a transmembrane glycoprotein implicated in cell-cell adhesion and cancer metastasis. The expression of CDH22 has been shown to be increased in colorectal cancers. However, the role of CDH22 in melanomagenesis is not known.

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The lesion bypass pathway, which is regulated by monoubiquitination of proliferating cell nuclear antigen (PCNA), is essential for resolving replication stalling due to DNA lesions. This process is important for preventing genomic instability and cancer development. Previously, it was shown that cells deficient in tumour suppressor p33ING1 (ING1b) are hypersensitive to DNA damaging agents via unknown mechanism.

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Myeloid leukemia-1 (Mcl-1) is an anti-apoptotic protein implicated in tumor progression. Its expression was found to be elevated in many types of human cancers and is correlated with tumor progression. The expression of Mcl-1 in melanoma is not fully understood.

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Arsenic is a toxic metal that can cause death following exposure. In an unusual event, seven patients unintentionally applied a 30% arsenic solution to their entire body instead of a benzyl benzoate solution to treat their scabies. Hours later they developed severe skin reactions, including bullae, and were admitted to the hospital with gastrointestinal and cardiovascular disorders.

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In humans, reproduction was generally believed to be controlled by only one form of GnRH (called mammalian GnRH or GnRHI). However, recently, a second form of GnRH, analogous to chicken GnRHII, was discovered in several tissues, including the human ovary. The regulation and function of GnRHI in the hypothalamus has been well studied.

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