Side population cell level in human breast cancer and factors related to disease-free survival

Sinomenine Inhibits Vasculogenic Mimicry and Migration of Breast Cancer Side Population Cells via Regulating miR-340-5p/SIAH2 Axis

Hypoxia and its induced vasculogenic mimicry (VM) formation, which both closely related with stem-like side population (SP) cells, are the main culprits leading to tumor invasion and metastasis. Sinomenine exhibits excellent anticancer activity in breast cancer, but whether and how it affects hypoxia-triggered VM formation in breast cancer SP cells remains unclear. In this study, breast cancer SP cells were sorted from MDA-MB-231 cells and cultured with sinomenine under hypoxic conditions. Sinomenine obviously repressed the migration and VM formation of breast cancer SP cells. Through downregulating SIAH2 and HIF-1α, sinomenine can inhibit epithelial-mesenchymal transition process of breast cancer SP cells. SIAH2 was identified as a target of miR-340-5p and was downregulated by it, and sinomenine can upregulate miR-340-5p. Hypoxia-induced downregulation of miR-340-5p and activation of SIAH2/HIF-1α pathway can be both counteracted by the sinomenine. Moreover, miR-340-5p inhibition and SIAH2 overexpression can partly counteract the anticancer effects of sinomenine. Taken together, sinomenine inhibits hypoxia-caused VM formation and metastasis of breast cancer SP cells by regulating the miR-340-5p/SIAH2 axis.

Natural killer cells efficiently target multiple myeloma clonogenic tumor cells

The multiple myeloma (MM) landscape has changed in the last few years, but most patients eventually relapse because current treatment modalities do not target clonogenic stem cells, which are drug-resistant and can self-renew. We hypothesized that side population (SP) cells represent myeloma clonogenic stem cells and, searching for new treatment strategies, analyzed the anti-myeloma activity of natural killer (NK) cells against clonogenic cells. Activated and expanded NK cells (NKAE) products were obtained by co-culturing NK cells from MM patients with K562-mb15-41BBL cell line and characterized by flow cytometry. Functional experiments against MM cells were performed by Eu-TDA release assays and methylcellulose clonogenic assays. Side population was detected by Dye Cycle Violet labeling and then characterized by flow cytometry and RNA-Seq. Self-renewal capacity was tested by clonogenic assays. Sorting of both kind of cells was performed for time-lapse microscopy experiments. SP cells exhibited self-renewal potential and overexpressed genes involved in stem cell metabolism. NK cells from MM patients exhibited dysregulation and had lower anti-tumor potential against clonogenic cells than healthy donors’ NK cells. Patients’ NK cells were activated and expanded. These cells recovered cytotoxic activity and could specifically destroy clonogenic myeloma cells. They also had a highly cytotoxic phenotype expressing NKG2D receptor. Blocking NKG2D receptor decreased NK cell activity against clonogenic myeloma cells, and activated NK cells were able to destroy SP cells, which expressed NKG2D ligands. SP cells could represent the stem cell compartment in MM. This is the first report describing NK cell activity against myeloma clonogenic cells.

Acquisition of a side population fraction augments malignant phenotype in ovarian cancer

Side population (SP) cells harbor malignant phenotypes in cancer. The aim of this study was to identify genes that modulate the proportion of ovarian cancer SP cells. Using a shRNA library targeting 15,000 genes, a functional genomics screen was performed to identify genes whose suppression increased the SP percentage. The biological effects caused by alteration of those identified genes were investigated in vitro and in vivo. We found that suppression of MSL3, ZNF691, VPS45, ITGB3BP, TLE2, and ZNF498 increased the proportion of SP cells. Newly generated SP cells exhibit greater capacity for sphere formation, single cell clonogenicity, and in vivo tumorigenicity. On the contrary, overexpression of MSL3, VPS45, ITGB3BP, TLE2, and ZNF498 decreased the proportion of SP cells, sphere formation capacity and single cell clonogenicity. In ovarian cancer cases, low expression of MSL3, ZNF691 and VPS45 was related to poor prognosis. Suppression of these six genes enhanced activity of the hedgehog pathway. Cyclopamine, a hedgehog pathway inhibitor, significantly decreased the number of SP cells and their sphere forming ability. Our results provide new information regarding molecular mechanisms favoring SP cells and suggest that Hedgehog signaling may provide a viable target for ovarian cancer.

Combination Technique Is Superior to Dye Alone in Identification of the Sentinel Lymph Node in Male Breast Cancer

Sentinel lymph node (SLN) biopsy is the main method in staging the axilla. There are insufficient data available regarding the accuracy of an SLN biopsy in male breast cancer. The aim of this study is to evaluate whether the combination of dye and radiotracer would improve the detection rate of SLNs versus dye alone in male breast cancer patients. From February 2009 to January 2012, our SLN biopsy database was retrospectively reviewed to identify male breast cancer cases. Of the 890 SLN procedures contained in the database, 10 male breast cancer patients were identified. Patient age, body mass index, SLN biopsy technique, SLN identification, number of SLN excised, and pathology reports were reviewed. Mean age was 57.2 (34–85) years with a mean tumor size was 2.2 (1.0–4.0) cm. SLN detection ratios were two in four with blue dye and six in six with the combination technique. Overall, SLNs were identified in 8 of the 10 patients. SLN biopsy is applicable in male breast cancer cases. The addition of a radiotracer to the dye in SLN biopsy increases the detection rate of sentinel nodes in male breast cancer patients.

Do Different Stemness Markers Identify Different Pools of Cancer Stem Cells in Malignancies: A Study on ER+ and ER-Breast Cancer Cell Lines

In view of popularity of cancer stem cell (CSC) model all events in evolution of cancer are being explained in that context. Breast cancer is first solid tumor in which CSCs were identified. We aimed to compare stemness profile of two major subtypes [Estrogen receptor positive (ER⁺) and negative (ER^-)] breast cancer using different sets of markers. Expression of CD44/CD24, CK/Vimentin, E-Cadherin/Fibronectin and percentage of side population (SP) was studied in ER⁺ (T47D) and ER^- (MDA-MB-231) cell lines by flow cytometry. Breast CSCs (BCSCs) were sorted using CD44⁺/CD24^-/low expression and SP analysis and cultured. BCSCs were then compared with Non-CSCs (NCSCs) for response to drugs (Paclitaxel and Cisplatin), Ki67 and ER expression. Results showed higher expression of stemness markers (CD44⁺/CD24^-/low, CK⁺/Vimentin⁺ and E-Cadherin^-/Fibrinectin^F+) in MDA-MB-231 cells. Percentage SP representing BCSCs was found to be significantly more in later (3.20 ± 0.002 cf. T47D 1.25% ± 0.0007). BCSCs were found to be more resistant to drugs as compared to NCSCs in both cell lines. ER expression was weak in BCSCs sorted from T47D as compared to NCSCs. Ki67 was expressed in both BCSCs and NCSCs. Differences in expression of stemness markers help to explain aggressive behavior, higher recurrence rate and metastatic potential of MDA-MB-231 cells. However, no correlation amongst different markers used suggests that they may be identifying varied populations of cells in tumor hierarchy. A weak ER expression in BCSCs may be strategy used by BCSCs to escape effect of hormone therapy in ER⁺ breast cancers.

Ameliorative Effects of Chloroform Fraction of Cocos nucifera L. Husk Fiber Against Cisplatin-induced Toxicity in Rats

Background:

Cisplatin (Cis) is used in the treatment of solid tumors and is known to elicit serious side effects.

Objective:

The present study investigated the protective effects of chloroform fraction of Cocos nucifera husk fiber (CFCN) against Cis-induced organs’ damage and chromosomal defect in rats. Quercetin (QUE), standard antioxidant, served as positive control.

Materials and Methods:

Thirty male Wistar rats were assigned into six groups and treated with corn oil (control), Cis alone, Cis + CFCN, CFCN alone, Cis + QUE, and QUE alone. QUE and CFCN were given at 50 and 200 mg/kg/day, respectively, by oral gavage for 7 days before the rats were exposed to a single dose of Cis (10 mg/kg, intraperitoneal) at the last 36 h of study.

Results:

Administration of Cis alone caused a significant (P < 0.05) increase in the levels of serum creatinine and urea by 72% and 70%, respectively, when compared with the control. The activity of serum aspartate aminotransferase was significantly (P < 0.05) increased while alanine aminotransferase and alkaline phosphatase were insignificantly (P > 0.05) affected in Cis-treated rats. Furthermore, the activities of hepatic and renal catalase, superoxide dismutase, glutathione S-transferase, glutathione peroxidase, and levels of reduced glutathione were significantly (P < 0.05) decreased in Cis-treated rats with concomitant elevation of malondialdehyde. Cis exposure increased the frequency of micro nucleated polychromatic erythrocytes (mPCE) by 92%. Pretreatment with CFCN inhibited lipid peroxidation, enhanced the activities of some antioxidative enzymes and reduced the frequency of mPCE.

Conclusions:

Chloroform fraction of CFCN may protect against organs damage by Cis. Further studies are required to determine the component of the plant responsible for this activity.

SUMMARY

Cisplatin (Cis) is used in the treatment of solid tumors and is known to elicit serious side effects. This study investigated the protective effects of chloroform fraction of Cocos nucifera husk fiber (CFCN) against Cis-induced organs’ damage while quercetin (QUE) served as standard antioxidant.

Thirty male Wistar rats were assigned into six groups and treated with corn oil (Control), Cis alone, Cis + CFCN, CFCN alone, Cis + QUE and QUE alone.

QUE and CFCN were given at 50 and 200 mg/kg/day respectively by oral gavage for seven days before the rats were exposed to a single dose of Cis (10mg/kg, i.p.) at the last 36 h of study. Results indicate that administration of Cis caused a significant (P<0.05) increase in the levels of serum creatinine and urea by 72% and 70% respectively.

The activity of serum aspartate aminotransferase was significantly (P <0.05) increased while alanine aminotransferase and alkaline phosphatase were insignificantly (P>0.05) affected in Cis-treated rats.

The activities of hepatic and renal catalase, superoxide dismutase, glutathione-s-transferase, glutathione peroxidase and levels of reduced glutathione were significantly (P<0.05) decreased in Cis-treated rats with concomitant elevation of malondialdehyde.

Cis exposure increased the frequency of micronucleated polychromatic erythrocytes (mPCE) by 92%.

Pretreatment with CFCN inhibited lipid peroxidation, enhanced the activities of some antioxidative enzymes and reduced the frequency of mPCE. The findings suggest that CFCN may protect against organs damage by cisplatin.

Further studies are required to determine the component of the plant responsible for this activity.