Shikonin selectively induces apoptosis in human prostate cancer cells through the endoplasmic reticulum stress and mitochondrial apoptotic pathway.

BACKGROUND: Despite the recent progress in screening and therapy, a majority of prostate cancer cases eventually attain hormone refractory and chemo-resistant attributes. Conventional chemotherapeutic strategies are effective at very high doses for only palliative management of these prostate cancers. Therefore chemo-sensitization of prostate cancer cells could be a promising strategy for increasing efficacy of the conventional chemotherapeutic agents in prostate cancer patients. Recent studies have indicated that the chemo-preventive natural agents restore the pro-apoptotic protein expression and induce endoplasmic reticulum stress (ER stress) leading to the inhibition of cellular proliferation and activation of the mitochondrial apoptosis in prostate cancer cells. Therefore reprogramming ER stress-mitochondrial dependent apoptosis could be a potential approach for management of hormone refractory chemoresistant prostate cancers. We aimed to study the effects of the natural naphthoquinone Shikonin in human prostate cancer cells. RESULTS: The results indicated that Shikonin induces apoptosis in prostate cancer cells through the dual induction of the endoplasmic reticulum stress and mitochondrial dysfunction. Shikonin induced ROS generation and activated ER stress and calpain activity. Moreover, addition of antioxidants attenuated these effects. Shikonin also induced the mitochondrial apoptotic pathway mediated through the enhanced expression of the pro-apoptotic Bax and inhibition of Bcl-2, disruption of the mitochondrial membrane potential (MMP) followed by the activation of caspase-9, caspase-3, and PARP cleavage. CONCLUSION: The results suggest that shikonin could be useful in the therapeutic management of hormone refractory prostate cancers due to its modulation of the pro-apoptotic ER stress and mitochondrial apoptotic pathways.

Nuclear factor I-C overexpression promotes monocytic development and cell survival in acute myeloid leukemia.

Nuclear factor I-C (NFIC) belongs to a family of NFI transcription factors that binds to DNA through CAATT-boxes and are involved in cellular differentiation and stem cell maintenance. Here we show NFIC protein is significantly overexpressed in 69% of acute myeloid leukemia patients. Examination of the functional consequences of NFIC overexpression in HSPCs showed that this protein promoted monocytic differentiation. Single-cell RNA sequencing analysis further demonstrated that NFIC overexpressing monocytes had increased expression of growth and survival genes. In contrast, depletion of NFIC through shRNA decreased cell growth, increased cell cycle arrest and apoptosis in AML cell lines and AML patient blasts. Further, in AML cell lines (THP-1), bulk RNA sequencing of NFIC knockdown led to downregulation of genes involved in cell survival and oncogenic signaling pathways including mixed lineage leukemia-1 (MLL-1). Lastly, we show that NFIC knockdown in an ex vivo mouse MLL::AF9 pre-leukemic stem cell model, decreased their growth and colony formation and increased expression of myeloid differentiation markers Gr1 and Mac1. Collectively, our results suggest that NFIC is an important transcription factor in myeloid differentiation as well as AML cell survival and is a potential therapeutic target in AML.

Centchroman inhibits proliferation of head and neck cancer cells through the modulation of PI3K/mTOR pathway.

Centchroman (CC; 67/20; INN: Ormeloxifene) is a non-steroidal antiestrogen extensively used as a female contraceptive in India. In the present study, we report the anti-proliferative effect of CC in head and neck squamous cell carcinoma (HNSCC) cells. CC inhibited cell proliferation in a dose dependent manner at 24 h of treatment. Further studies showed that CC treatment induced apoptosis, inhibited Akt/mTOR and signal transducers and activators of transcription protein 3 (STAT3) signaling, altered proteins associated with cell cycle regulation and DNA damage and inhibited colony forming efficiency of HNSCC cells. In addition, CC displayed anti-proliferative activity against a variety of non-HNSCC cell lines of diverse origin. The ability of CC to serve as a dual-inhibitor of Akt/mTOR and STAT3 signaling warrants further studies into its role as a therapeutic strategy against HNSCC.

Association of thyroid peroxidase antibody and dyslipidemia in subclinical hypothyroidism.

CONTEXT: Subclinical hypothyroidism (SCH) is stated as mild thyroid failure, is more common as compared to overt hypothyroidism, is associated with different biochemical abnormalities such as dyslipidemia, and is also having high conversion rate into overt hypothyroidism in patients having thyroid peroxidase (TPO) antibody positive. Lipid abnormalities are controversial in SCH and there is lack of Indian studies showing correlation between lipid abnormalities and TPO positivity in SCH. Hence, we did this study to find the TPO positivity and associated dyslipidemia in SCH patients. MATERIALS AND METHODS: It was a prospective observational study from January 2015 to December 2015 including fifty adult diagnosed SCH patients presented in outpatient department of Sri Balaji Action Medical Institute, Paschim Vihar, New Delhi. TPO positivity and different lipid abnormalities were studied in those fifty diagnosed SCH patients, and finally, association between TPO antibody and dyslipidemia was calculated. RESULTS: Females were predominant (86%). TPO was positive in 56% SCH patients. Dyslipidemia was found in 100% of SCH patients with positive TPO antibody. In overall, TPO positive patients as well as TPO positive females, total cholesterol, triglyceride, and low-density lipoprotein were significantly high while high-density lipoprotein was insignificant. In males, no significant association was found. CONCLUSION: In SCH patients, dyslipidemia is significantly associated with TPO positivity, especially in females. Hence, early screening, diagnosis, and treatment of SCH patients are recommended to prevent further risks.

ROS mediated pro-apoptotic effects of Tinospora cordifolia on breast cancer cells.

The inevitable development of chemoresistance and unmanageable side effects are the major therapeutic challenges in management of breast cancer imposing an urgent need for identification of novel therapeutic agents. In the present investigation, we report anti-proliferative activity of chloroform fraction of Tinospora cordifolia (TcCF), an Ayurvedic medicinal plant, on breast cancer cells. We found that TcCF inhibited growth of breast cancer cells, MDA-MB-231 and MCF-7. More interestingly, we observed TcCF treatment increased intra-cellular ROS levels, altered expression of pro and anti-apoptotic genes, decreased colony formation ability and induced apoptosis in breast cancer cells. We also found that inhibition of ROS abrogated TcCF induced apoptosis in breast cancer cells, emphasizing the role ROS in TcCF induced breast cancer cell death. Furthermore, we identified the presence of pharmacologically active compounds like rutin and quercetin which account for the anti-cancer property of TcCF against breast cancer cells. These data show TcCF is a promising anti-cancer agent against breast cancer cells.

Proteasome inhibition mediates p53 reactivation and anti-cancer activity of 6-gingerol in cervical cancer cells.

Human papilloma virus (HPV) expressing E6 and E7 oncoproteins, is known to inactivate the tumor suppressor p53 through proteasomal degradation in cervical cancers. Therefore, use of small molecules for inhibition of proteasome function and induction of p53 reactivation is a promising strategy for induction of apoptosis in cervical cancer cells. The polyphenolic alkanone, 6-Gingerol (6G), present in the pungent extracts of ginger (Zingiber officinale Roscoe) has shown potent anti-tumorigenic and pro-apoptotic activities against a variety of cancers. In this study we explored the molecular mechanism of action of 6G in human cervical cancer cells in vitro and in vivo. 6G potently inhibited proliferation of the HPV positive cervical cancer cells. 6G was found to: (i) inhibit the chymotrypsin activity of proteasomes, (ii) induce reactivation of p53, (iii) increase levels of p21, (iv) induce DNA damage and G2/M cell cycle arrest, (v) alter expression levels of p53-associated apoptotic markers like, cleaved caspase-3 and PARP, and (vi) potentiate the cytotoxicity of cisplatin. 6G treatment induced significant reduction of tumor volume, tumor weight, proteasome inhibition and p53 accumulation in HeLa xenograft tumor cells in vivo. The 6G treatment was devoid of toxic effects as it did not affect body weights, hematological and osteogenic parameters. Taken together, our data underscores the therapeutic and chemosensitizing effects of 6G in the management and treatment of cervical cancer.

Serum vascular endothelial growth factor-A (VEGF-A) as a biomarker in squamous cell carcinoma of head and neck patients undergoing chemoradiotherapy.

BACKGROUND: To evaluate serum VEGF-A levels in squamous cell carcinoma of head and neck (SCCHN) patients and relationships with response to therapy. MATERIALS AND METHODS: Serum VEGF-A levels in patients (n=72) treated with radiotherapy (RT) or radio-chemotherapy (RCT) and controls (n=40) were measured by ELISA. RESULTS: Serum VEGF-A levels of the SCCHN cases were significantly higher (p=0.001) than in healthy controls, and in patients with positive as compared to negative lymph node status (p=0.004). Similarly, patients with advanced stage (Stage III-IV) disease had more greatly elevated levels of serum VEGF-A level than their early stage (Stage I-II) counterparts (p=0.001). In contrast, there was no significant difference (p=0.57) in serum level of VEGF-A in patients with advanced T-stage (T3-4) as compared to early stage (T1-2). Similarly, patients with distant metastasis had no significant (p=0.067) elevation in serum VEGF-A level as compared to non-metastatic disease. However, the non-responder patients had significantly higher serum VEGF-A level as compared to responders (p=0.001). CONCLUSIONS: Our results suggest that the serum VEGF-A level may be a useful biomarker for the prediction of response to therapy in SCCHN.