Superior Photodynamic Therapy of Colon Cancer Cells by Selenophene‐BODIPY‐Loaded Superparamagnetic Iron Oxide Nanoparticles

Investigation of cytotoxic activity properties of etoxazole towards human cancer and healthy cell lines and molecular docking studies.

Photodynamic therapy (PDT) of cancer is an alternative treatment for tumors resistant to chemo- and radiotherapy. It induces cancer cell death mainly through generation of reactive oxygen species by a laser light-activated photosensitizer. It has been suggested that the p53 tumor suppressor protein sensitizes some human cancer cells to PDT. However, there is still no direct evidence for this. We have demonstrated here for the first time that the photosensitizer protoporphyrin IX (PpIX) binds to p53 and disrupts the interaction between p53 tumor suppressor protein and its negative regulator HDM2 in vitro and in cells. Moreover, HCT116 colon cancer cells exhibited a p53-dependent sensitivity to PpIX in a dose-dependent manner, as was demonstrated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and fluorescence-activated cell sorter (FACS) analysis of cell cycle profiles. We have also observed induction of p53 target pro-apoptotic genes, e.g. puma (p53-up-regulated modulator of apoptosis), and bak in PpIX-treated cells. In addition, p53-independent growth suppression by PpIX was detected in p53-negative cells. PDT treatment (2 J/cm2) of HCT116 cells induced p53-dependent activation of pro-apoptotic gene expression followed by growth suppression and induction of apoptosis.

The fields of photodynamic therapy (PDT) and radiation therapy customarily rely on lasers operating at a fixed wavelength (typically 1064 nm Nd:YAG laser), primarily because of the traditional availability of such lasers. However, Raman fiber lasers have made concurrent technological progress to emerge as wavelength-agile laser sources, capable of providing high laser powers at any wavelength, primarily from the 1 -2.0 um wavelengths. In this work, we explore for the first time, the use of a high power, wavelength-tunable Raman fiber laser for performing a wavelength-dependent cell-killing effect study on cancerous and healthy cell lines. Specifically, we irradiate at different wavelengths (from 1 um to 1.6 um) breast cancer cells and healthy cells from a cell line, cultured in well plates. Our in-house built Raman laser is power-tunable apart from being wavelength-tunable, the power and duration of irradiation was optimised for achieving the best contrast between viability of cancerous vs. healthy cells. Flow cytometry is used for cell-viability tests. The results give interesting insights on the choice of wavelengths and we show that 1064 nm lasers traditionally used are not the best choice of wavelength to use for this application while 1480nm lasers performed best. We conclusively demonstrate that other wavelengths exist for achieving the best death rate in cancerous cells, leaving healthy cells unharmed. This can pave the way for deployment of Raman fiber lasers as an alternative laser source for this application which can tune the output wavelength to optimize the required laser tissue interaction. For the keywords, select up to 8 key terms for a search on your manuscript's subject.

Photodynamic therapy (PDT) is a promising and clinically approved method for the treatment of cancer. However, the efficacy of PDT is often limited by the poor selectivity and distribution of the photosensitizers (PS) toward the malignant tumors, resulting in prolonged periods of skin photosensitivity. In this work, we present a simple and straightforward strategy to increase the tumor distribution, selectivity, and efficacy of lipophilic PS zinc phthalocyanine (ZnPc) in colon cancer by their stabilization in purified, naturally secreted extracellular vesicles (EVs). The PS ZnPc was incorporated in EVs (EV-ZnPc) by a direct incubation strategy that did not affect size distribution or surface charge. By using co-culture models simulating a tumor microenvironment, we determined the preferential uptake of EV-ZnPc toward colon cancer cells when compared with macrophages and dendritic cells. We observed that PDT promoted total tumor cell death in normal and immune cells, but showed selectivity against cancer cells in co-culture models. In vivo assays showed that after a single intravenous or intratumoral injection, EV-ZnPc were able to target the tumor cells and strongly reduce tumor growth over 15 days. These data expose opportunities to enhance the potential and efficacy of PDT using simple non-synthetic strategies that might facilitate translation into clinical practice.

Current cancer treatments damage healthy cells and tissues, causing short-term and long-term side effects. New treatments are desired that show greater selectivity toward cancer cells and evade the common mechanisms of multidrug resistance. Membranolytic anticancer peptides (mACPs) hold promise against cancer and multidrug resistance. Amphipathicity, hydrophobicity, and net charge of mACPs participate in their respective interactions with cell membranes and their overall inhibition of cancer cells. To support the design of cell-line selective mACPs, we investigated the relationships that amino acid composition, physicochemical properties, sequence motifs, and sequence homology could have with their potency and selectivity towards several healthy and cancer cell lines. Sequence length and net charge are known to affect the selectivity of mACPs between cancer and healthy cell lines. Our study reveals that increasing the net charge or flexibility (i. e., small and aliphatic residues) influences their selectivity between cancer cell lines with comparable lipid compositions.

Aim: Patulin, a mycotoxin, is an organic compound classified as a polypeptide. Patulin, which is generally detected in moldy fruits and their derivatives, has been suggested to have anticancer activity. Some studies have shown that it induces apoptosis in the cell. This study aims to investigate the anticancer activity of patulin in SH-SY5Y (human neuroblastoma cell line), HCT116 (human colon cancer cell line), and MCF-7 (human breast cancer cell line) cell lines. Materials and Methods: SH-SY5Y, HCT116, MCF-7, and L929 (healthy fibroblast) cell lines were used for cytotoxicity experiments. Cells were added in 96-well plates at 5x103 cells per well. Serial dilutions of patulin at a dose of 1, 2.5, 5, 10, 25, 50, and 100 µM were added to the waiting cells in 24 hours incubation. All cell lines were exposed to patulin for 24 and 48 hours. The cytotoxic activity of patulin in cancer and healthy cell lines was determined in vitro by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium) cell viability test. The results of the toxicity tests were measured spectrophotometrically (450 nm) in ELISA at intervals of 24 hours for 2 days. Results: Patulin caused cytotoxic activity in all cell lines at a concentration of 100 µM. Patulin showed cytotoxic activity at low doses only in the SH-SY5Y cell line. At doses of 25 and 50 µM, HCT116 caused more than 50% death in the cell line, while higher concentrations induced cell death in the MCF-7 cell line. Conclusion: Patulin showed anticancer activity at high concentrations in colon and breast cancer cell lines, and both low and high concentrations in the SH-SY5Y cell line. Patulin may be a new candidate molecule in the treatment of neuroblastoma, colon, and breast cancers, depending on the dose.

Magnetic stomatocyte-like nanomotor as photosensitizer carrier for photodynamic therapy based cancer treatment

Unveiling the molecular mechanisms involved in the cytotoxicity induced by photodynamic therapy in human breast cancer cells

Farnesol (trans, trans-3,7,11-trimethyl-2,6,10-dodecatriene-1-ol) is an essential oil component that can be found in a variety of plants. In this study, in vitro effects of farnesol on human lung cancer A549 cell line, colon adenocarcinoma (Caco-2) cell line and healthy human lung epithelial BEAS-2B cell lines, WST-1 cytotoxicity test, dual staining of cell survival (DAPI-PI) analysis, micronucleus test, and transmission electron microscopy (TEM). Farnesol acted in a concentration-dependent manner at the dose ranges studied for cancer cell lines, and while at certain doses it reduced proliferation, interestingly at higher concentrations it induced growth more than the control. In the healthy BEAS-2B cell line, it was tested over a wide range of doses and at all studied concentrations, it did not suppress cellular growth, but rather increased. This seems promising in that farnesol harms cancer cell lines but does not cause significant damage to healthy cells. Obtained TEM data after treatment with farnesol at IC50 dose showed both autophagic and apoptotic findings in cancer cell lines compared to control, and normal findings exhibited in BEAS-2B cell line, cell survival, and micronucleus analyzes showed the presence of apoptotic findings and chromosomal damage as a result of farnesol application in cancer cell lines. RESEARCH HIGHLIGHTS: Farnesol has dose-dependent effects on human lung cancer and colon adenocarcinoma cell lines, with no significant damaging effects on healthy human lung epithelial cell lines. TEM, cell survival, and micronucleus findings support the findings of autophagic, apoptotic, and chromosomal damage on cancer cell lines.

Alkaline phosphatase and dipeptidyl peptidase are markers of differentiation in colon cancer cells. In colon cancer cells differentiation can often be induced by treatment with inhibitors of histone deacetylase (HDAC) activity. In some colon cancer cells butyrate causes a several-fold induction of alkaline phosphatase but only modest effects on dipeptidyl peptidase. There is relatively little information on changes in activity of cell surface hydrolases in bladder cancer. However, there is some evidence for decreased alkaline phosphatase activity in bladder cancer. We tested the hypothesis that there may be retention of activity in more slowly growing cancer cells and the activity will be regulated by HDAC inhibitors in a manner similar to that in colon cancer. In our initial studies we screened seven human bladder cancer cell lines for alkaline phosphatase activity. We identified three cell lines (5637, HT1197 and HT1376) with activity comparable to that in more differentiated colon cancer cell lines. The response to incubation with the HDAC inhibitors butyrate and valproate was compared with effects in three colon cancer cell lines Caco-2, HT29 and SW1116. In all six cell lines there were growth inhibitory effects that tended to be a little greater with butyrate than with valproate. Induction of alkaline phosphatase activity was generally greater with butyrate than with valproate and was apparent even without normalizing the activity on a protein basis. After determining the activity per unit protein there were increases in dipeptidyl peptidase activity after treatment with the HDAC inhibitors that were smaller than for alkaline phosphatase. Growth inhibition was observed with all the HDAC inhibitors examined including LMK235, nicotinamide, RGFP966, romidepsin and tubacin but increased activity of alkaline phosphatase was not always seen. Activities of the enzymes were very low in CRL1790 human colonocytes of fetal origin and there was little or no induction with HDAC inhibitors. Although pyruvate and carnitine have been reported to be HDAC inhibitors, incubation with colon and bladder cancer cells did not cause induction of alkaline phosphatase activity. It was concluded that regulation of alkaline phosphatase and dipeptidyl peptidase by HDAC inhibitors can be similar in bladder and colon cancer cells. Citation Format: Michael A. Lea, Lauren Cué, Elizabeth Batista, Erik Lew, Charles desBordes. Effects of histone deacetylase inhibitors on differentiation markers and growth of colon and bladder cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1386. doi:10.1158/1538-7445.AM2017-1386

Intravitreal Triamcinolone and PDT

Photodynamic therapy (PDT) is a highly specific anticancer treatment modality for various cancers, particularly for recurrent cancers that no longer respond to conventional anticancer therapies. PDT has been under development for decades, but light-associated toxicity limits its clinical applications. To reduce the toxicity of PDT, we recently developed a targeted nanoparticle (NP) platform that combines a second-generation PDT drug, Pc 4, with a cancer targeting ligand, and iron oxide (IO) NPs. Carboxyl functionalized IO NPs were first conjugated with a fibronectin-mimetic peptide (Fmp), which binds integrin β1. Then the PDT drug Pc 4 was successfully encapsulated into the ligand-conjugated IO NPs to generate Fmp-IO-Pc 4. Our study indicated that both nontargeted IO-Pc 4 and targeted Fmp-IO-Pc 4 NPs accumulated in xenograft tumors with higher concentrations than nonformulated Pc 4. As expected, both IO-Pc 4 and Fmp-IO-Pc 4 reduced the size of HNSCC xenograft tumors more effectively than free Pc 4. Using a 10-fold lower dose of Pc 4 than that reported in the literature, the targeted Fmp-IO-Pc 4 NPs demonstrated significantly greater inhibition of tumor growth than nontargeted IO-Pc 4 NPs. These results suggest that the delivery of a PDT agent Pc 4 by IO NPs can enhance treatment efficacy and reduce PDT drug dose. The targeted IO-Pc 4 NPs have great potential to serve as both a magnetic resonance imaging (MRI) agent and PDT drug in the clinic.

In a recent clinical study, we showed that hypericin accumulates selectively in urothelial lesions of the bladder following intravesical administration of the compound in patients. This observation infers that hypericin, a potent photosensitizer, could be used as a selective photodynamic therapy (PDT) tool against superficial bladder cancer. In the present study we investigated the in vivo PDT activity of hypericin in transition cell carcinoma (TCC) tumors of the bladder. Both the distribution and tumor PDT response were carried out using subcutaneous heterotopic AY-27 TCC tumors in syngeneic rats. For both PDT and distribution studies, hypericin (1 or 5 mg/kg) was injected intravenously 0.5, 6 or 24 h before PDT or distribution evaluation. The data show that hypericin is a potent photosensitizer in the treatment of TCC tumors in vivo and that the interval between drug administration and photo-irradiation has a dramatic effect on the PDT outcome. Using a 0.5 h interval between drug administration and photo-irradiation the tumor regrowth study indicated that no tumor mass could me measured 9-10 days after PDT. On the contrary, lengthening the time interval between drug administration and photo-irradiation resulted in a gradual loss of PDT efficiency in these tumors. For instance, while the 6 h drug interval protocol produced a moderate PDT activity in which the tumor sizes decreased to about 50% of their original sizes 11-16 days after photo-irradiation, the 24 h interval protocol was even less effective. The distribution data indicate that the PDT efficiency of hypericin in TCC tumors corresponded to the plasma concentrations rather than to the over all concentrations in the tumor. It is therefore conceivable that the mechanism of PDT efficacy of hypericin in TCC tumors is through indirect (vascular effects) rather than through direct effects (cellular destruction) of hypericin in these tumors. In conclusion, our data indicate that hypericin is a potent photosensitizer against AY-27 TCC tumors and that the PDT efficacy of hypericin is largely determined by photosensitizer distribution in the tumor at the time of photo-irradiation.

Intracellular glutathione levels affect the outcomes of verteporfin-mediated photodynamic therapy in esophageal cancer cells

Monitoring of the PDT by infrared images – A clinic study