Zoledronate and Molecular Iodine Cause Synergistic Cell Death in Triple Negative Breast Cancer through Endoplasmic Reticulum Stress

Anticancer Activity of Sargassum fluitans Extracts in Different Cancer Cells

BACKGROUND

The arrival of large quantities of Sargassum in the Mexican Caribbean Sea has generated major environmental, health and economic problems. Although Sargassum has been used in the generation of some commercial products, few studies have described its possible applications as a source of compounds with anticancer activity.

OBJECTIVE

This study aimed to evaluate the antiproliferative effects of different Sargassum extracts on various cancer cell lines. Furthermore, LC/QTOF-MS was used to identify the compounds related to the antiproliferative effect.

METHODS

First, determination of the seaweed was performed, and dichloromethane, chloroform and methanol extracts were obtained. The extracts were evaluated for their antiproliferative effects by MTT in breast (MDAMB- 231 and MCF-7), prostate (DU-145), lung (A549) and cervical (SiHa) cancer cell lines. Finally, LC/QTOFMS identified the compounds related to the antiproliferative effect.

RESULTS

The authentication showed Sargassum fluitans as the predominant species. The extracts of dichloromethane and chloroform showed an antiproliferative effect. Interestingly, the fractionation of the chloroform extract showed two fractions (FC1 and FC2) with antiproliferative activity in MDA-MB-231, SiHa and A549 cancer cell lines. On the other hand, three fractions of dichloromethane extract (FD1, FD4 and FD5) also showed antiproliferative effects in the MDA-MB-231, MCF-7, SiHa and DU-145 cancer cell lines. Furthermore, LC/QTOF-MS revealed the presence of eight major compounds in FC2. Three compounds with evidence of anticancer activity were identified (D-linalool-3-glucoside, (3R,4S,6E,10Z)-3,4,7,11-tetramethyl-6,10-tridecadienal and alpha-tocotrienol).

CONCLUSION

These findings showed that Sargassum fluitans extracts are a possible source of therapeutic agents against cancer and could act as scaffolds for new drug discovery.

CD73 regulates zoledronate-induced lymphocyte infiltration in triple-negative breast cancer tumors and lung metastases

Introduction

Bisphosphonates (BPs) are bone-protecting osteoclast inhibitors, typically used in the treatment of osteoporosis and skeletal complications of malignancies. When given in the adjuvant setting, these drugs may also prevent relapses and prolong overall survival in early breast cancer (EBC), specifically among postmenopausal patients. Because of these findings, adjuvant nitrogen-containing BPs (N-BPs), such as zoledronate (ZOL), are now the standard of care for high-risk EBC patients, but there are no benefit-associated biomarkers, and the efficacy remains low. BPs have been demonstrated to possess anti-tumor activities, but the mechanisms by which they provide the beneficial effects in EBC are not known.

Methods

We used stably transfected 4T1 breast cancer cells together with suppression of CD73 (sh-CD73) or control cells (sh-NT). We compared ZOL effects on tumor growth and infiltrating lymphocytes (TILs) into tumors and lung metastases using two mouse models. B cell depletion was performed using anti-CD20 antibody.

Results

Sh-CD73 4T1 cells were significantly more sensitive to the growth inhibitory effects of n-BPs in vitro. However, while ZOL-induced growth inhibition was similar between the tumor groups in vivo, ZOL enhanced B and T lymphocyte infiltration into the orthotopic tumors with down-regulated CD73. A similar trend was detected in lung metastases. ZOL-induced tumor growth inhibition was found to be augmented with B cell depletion in sh-NT tumors, but not in sh-CD73 tumors. As an internal control, ZOL effects on bone were similar in mice bearing both tumor groups.

Discussion

Taken together, these results indicate that ZOL modifies TILs in breast cancer, both in primary tumors and metastases. Our results further demonstrate that B cells may counteract the growth inhibitory effects of ZOL. However, all ZOL-induced TIL effects may be influenced by immunomodulatory characteristics of the tumor.

Combination of in situ iodization and Haloferax spp. bacteria enrichment in salt crystallization process

Salts that meet the standard quality are enriched with micronutrients, such as potassium iodate, at least 30 ppm. The iodization can be carried out directly in crystallization ponds (in-situ iodization) in salt fields. This paper reports the effectiveness of in-situ iodization technology combined with the enrichment of Halophilic bacteria consortium and Haloferax spp. to produce bio-based NaCl salt. The brine was first crystallized under sunlight exposure for approximately five days with water temperatures of 32-39 °C and an average wind speed of 2.8-6.0 m/s in each pond with a dimension of 20 × 20 m. Following this, the performance of these bacteria was analyzed in terms of the resulting final concentration of KIO3 (ppm), NaCl concentration (v/v), and water content (v/v). Results showed that the treatment with in situ iodization and Haloferax spp. successfully produce better bio-based salt quality in terms of KIO3 level, NaCl purity, and water contents. Moreover, the method did not produce aqueous and solid wastes, unlike in the conventional salt industry. The optimum condition was found at 50 ppm of KIO3 with the addition of Haloferax spp. SEM analysis shows that the treatment using Haloferax spp. resulted in a larger rectangular and harder crystal salt than the controls.

New Insight into Triple-Negative Breast Cancer Therapy: The Potential Roles of Endoplasmic Reticulum Stress and Autophagy Mechanisms

BACKGROUND

Breast cancer is accounted as the fifth leading cause of mortality among the other cancers. Notwithstanding, Triple Negative Breast Cancer (TNBC) is responsible for 15-20% of breast cancer mortality. Despite many investigations, it remains incurable in part due to insufficient understanding of its exact mechanisms.

METHODS

A literature search was performed in PubMed, SCOPUS and Web of Science databases using the keywords autophagy, Endoplasmic Reticulum (ER) stress, apoptosis, TNBC and the combinations of these keywords.

RESULTS

It was found that autophagy plays a dual role in cancer, so that it may decrease the viability of tumor cells or act as a cytoprotective mechanism. It then appears that using compounds having modulatory effects on autophagy is of importance in terms of induction of autophagic cell death and diminishing the proliferation and metastasis of tumor cells. Also, ER stress can be modulated in order to stimulate apoptotic and autophagic cell death in tumor cells.

CONCLUSION

Perturbation in the signaling pathways related to cell survival leads to the initiation and progression of cancer. Regarding the advancement in the cancer pathology, it seems that modulation of autophagy and ER stress are promising.

Adjuvant Effect of Molecular Iodine in Conventional Chemotherapy for Breast Cancer. Randomized Pilot Study

This study analyzes an oral supplement of molecular iodine (I₂), alone and in combination with the neoadjuvant therapy 5-fluorouracil/epirubicin/cyclophosphamide or taxotere/epirubicin (FEC/TE) in women with Early (stage II) and Advanced (stage III) breast cancer. In the Early group, 30 women were treated with I₂ (5 mg/day) or placebo (colored water) for 7–35 days before surgery. For the Advanced group, 30 patients received I₂ or placebo, along with FEC/TE treatment. After surgery, all patients received FEC/TE + I₂ for 170 days. I₂ supplementation showed a significant attenuation of the side effects and an absence of tumor chemoresistance. The control, I₂, FEC/TE, and FEC/TE + I₂ groups exhibited response rates of 0, 33%, 73%, and 100%, respectively, and a pathologic complete response of 18%, and 36% in the last two groups. Five-year disease-free survival rate was significantly higher in patients treated with the I₂ supplement before and after surgery compared to those receiving the supplement only after surgery (82% versus 46%). I₂-treated tumors exhibit less invasive potential, and significant increases in apoptosis, estrogen receptor expression, and immune cell infiltration. Transcriptomic analysis indicated activation of the antitumoral immune response. The results led us to register a phase III clinical trial to analyze chemotherapy + I₂ treatment for advanced breast cancer.

The effect of intake of sausages fortified with β-CD-I2 complex on iodine status and thyroid function: A preliminary study

The present study evaluated influence of boiled sausages consumption fortified with β-CD-I₂ on the urinary iodine excretion (UIE) level of volunteers. Median urinary UIE level was increased from 58.02 (24.0-175.4) μg/L to 110.6 (20.5-231.6) μg/L during 10 days. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels were determined by radio immunoassay analysis. As it was expected, intake of sausages fortified with β-CD-I₂ resulted in rise of FT4 level from 1.1 (0.95-1.25) to 1.23 (1.07-1.63) ng/dL, whereas TSH level decreased from 1.53 (0.47-3.37) mIU/L to 1.1 (0.51-3.17) mIU/L. A dynamic gastrointestinal model in vitro was used in order to determine possibility of 3,5-diiodotyrosine (DIT) formation during consumption of the fortified sausages. The DIT concentration was determined by HPLC-MS method and was found to be 0.38 ng/mL in sausage dialyzate. These findings indicate that β-CD-I₂ introduction as an iodine carrier in boiled sausages may help to improve iodine status and to control organic iodine species concentration.

Iodine prevents the increase of testosterone-induced oxidative stress in a model of rat prostatic hyperplasia

Oxidative stress and inflammation are involved in the development and/or progression of benign prostatic hyperplasia (BPH). Molecular iodine (I₂) induces antiproliferative and apoptotic effects in prostate cancer cells, but it is unknown if I₂ regulates oxidative stress in the normal and/or tumoral prostate. The purpose of this study was to analyze the effects of I₂ and celecoxib (Cxb) on oxidative stress and inflammation in a model of prostatic hyperplasia. Cxb was used as positive control of cyclooxygenase-2 (COX-2) inhibition. Prostatic hyperplasia was induced in male Wistar rats (170g) with testosterone (5mg/kg/week, for three weeks). One week before hyperplasia induction, I₂ (25mg/day/rat) or Cxb (1.25mg/day/rat) was supplied for four weeks in the drinking water. Prostatic hyperplasia was evaluated by histological analysis, DNA content, and/or proliferating cell nuclear antigen (PCNA) expression. Lipoperoxidation (malondialdehyde) and nitrite (NO2^-) levels were analyzed by colorimetric methods, while nitric oxide synthase (NOS), COX, and myeloperoxidase (MPO) enzymes were analyzed using RT-PCR, immunoblotting, and/or enzymatic assays. Levels of 15-F2t-isoprostanes, prostaglandins (PGE₂), leukotrienes (LTB₄), and tumor necrosis factor alpha (TNFα) were measured by ELISA. Control testosterone-treated animals exhibited hyperplasia in the dorsolateral prostate, as well as increments in almost all oxidative parameters except for COX-1, TNFα, or MPO. I₂ and Cxb prevented epithelial hyperplasia (DNA content) and oxidative stress induction generated by testosterone in almost the same intensity, and the minimum I₂ dose required was 2.5mg/rat. The antioxidant capacity of I₂ was also analyzed in a cell-free system, showing that this element inhibited the conversion of nitrate (NO₃^-) to NO₂^-. I₂ did not modify the prostatic oxidative state in testosterone untreated rats. In summary, our data showed that antiproliferative and antioxidant effects of I₂ involve the inhibition of NOS and the COX-2 pathway. Further studies are necessary to analyze the therapeutic and/or adjuvant effects of I₂ with first-line medications used to treat BPH.