Modulation of COX2 and hTERT expression by Photodynamic Therapy in human colon cancer cells

Photodynamic therapy (PDT) was employed as a cancer therapy with photosensitizer (PS)-loaded cancer cells, eradicated by the reactive oxygen species after light activation. Cyclo-oxygenase 2 (COX2) is an enzyme expressed in 80% of colon adenocarcinoma and is one of the targets for effective cancer treatment. There is also uprising evidence that the human telomerase reverse transcriptase (hTERT), a catalytic component of telomerase, is reported as a promising indicator for monitoring cancer treatment. In this study, NPe6 mediated PDT on COX2 induced apoptosis in HT-29 was investigated. The cell cycle changes was analysed by flow cytometry and the hTERT expression at pre and post PDT was evaluated at transcription level by Taqman real time PCR. NPe6-PDT in HT-29 cells demonstrated anti-proliferating effect in a drug and light dose dependent manner. LD50 was achieved at 16μg/mL and 2J/cm2 at 4 hour-post treatment with a significant down-regulation of COX2 expression at LD30 and LD50 by immunohistochemical staining (IHC) (p<0.05, One-Way ANOVA). Membrane blebbing was detected in over 60% of cells. 35.2% of treated cells arrested in S-phase at LD50 after 24 hours by flow cytometry. A 0.25- and 0.6-fold down-regulation of hTERT mRNA expression was achieved at LD30 and LD50 respectively by TaqMan real-time PCR. To summarize, NPe6 mediated PDT down-regulated COX2 expression and triggered cell apoptosis. The hTERT can serve as an indicative marker for monitoring NPe6-PDT cancer treatment efficacy.published_or_final_versio

Anti-metastatic mechanism of Tian-Xian Liquid (TXL) and its bioactive fractions in human colorectal cancer cells and xenograft models

Poster Session A: abstract no. 29Colorectal carcinoma is the second most prevalent cancer with an up-rising trend in Hong Kong (Hong Kong Cancer Registry). Traditional Chinese medicine acts as a complementary alternative for tumour therapy with minimal side-effects and traumatic injuries. Tian-Xian Liquid (TXL), one of the well-known natural medicinal herbal formulations, has been commercially used as an anticancer dietary supplement for a decade without known adverse effects. This study aimed to investigate the anti-metastatic property of TXL and its bioactive fractions [butanol fraction (BU), ethyl-acetate fraction (EA) and aqueous fraction (WA)] at molecular level on human colorectal cancer in vitro (HT-29 cancer cells) and in vivo (nude mice xenografts). For the cell model, TXL and its bioactive fractions have similar anti-proliferative effects by MTT assay. At 4-hour-incubation, IC50 values were obtained at 1% (V/V) TXL, 1.25% (V/V) BU, 5% (V/V) EA and 0.3125% (V/V) WA. At IC50, TXL and its bioactive fractions significantly reduced the MMP2 and MMP7 expressions at mRNA level by real-time PCR. At protein level, TXL, BU and EA correspondingly down-regulated MMP2 (active form) and MMP7 protein from 24 to 48 hours; TXL and BU also down-regulated VEGF protein expression; however, no such effect was found in WA-treated cells. Further, only TXL, EA and WA effectively inhibited the cell migration at 48 hours incubation by woundhealing assay. For the xenografts models, MMP2 and MMP7 mRNA expressions were reduced by TXL-, BU- and EA-treated xenografts; however no effects on MMP2 protein expression in all drug-treated xenografts. The VEGF protein expression was significantly down-regulated in TXL- and WA-treated xenografts. Further, TXL, BU and WA effectively inhibited the tumor growth without altering the body weight of the xenografts. In summary, the Chinese medicinal formulation, TXL, demonstrated the most effective anti-metastatic ability on human colorectal cancer in vitro and in vivo.published_or_final_versio

Potential therapeutic efficacy of photodynamic therapy on triple negative breast cancer in hormonal microenvironment

SignificanceThere are seldom studies on the determination of cancer treatment efficacy related to normal hormonal tumor microenvironment on triple negative breast cancer (TNBC). This study aimed to determine Hexyl-ALA-PDT efficacy on TNBC in a simulated hormonal microenvironment.ApproachThe 3D spheroids of TNBC cells (MDA-MB-231) were generated in the hormonal supplemented microenvironment. The accumulation of PpIX, phototoxicity, the ROS level and p-ULK1 expression level mediated by Hexyl-ALA-PDT were determined by confocal microscopy, MTT assay and flow cytometry.ResultsA lower Hexyl-ALA concentration was required to achieve the same lethal dose of LD50 with hormonal supplement in 3D spheroids. It was found that the ROS level was increased at lower Hexyl-ALA-PDT dose in hormonal microenvironment, which also correlated the decrease of p-ULK1 expression by PDT.ConclusionsHexyl-ALA-PDT increased ROS level in TNBC in hormonal microenvironment; and with the reduced p-ULK1 expression thus indicating autophagy of cell death might be triggered

Tian Xian Liquid (TXL) induces apoptosis in HT-29 colon cancer cell in vitro and inhibits tumor growth in vivo

2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

P28-6 Evaluation of PDT efficacy by an intense pulsed laser in breast cancer spheroids in simulated hormonal microenvironment

IntroductionBreast cancer ranked the most prevalence malignancies among women in Hong Kong with 13% mortality rate in 2021. Photodynamic therapy (PDT) is a cancer therapeutic approach via the combination of a photosensitizer (PS), light, and oxygen to generate reactive oxygen species leading to cancer cell destruction. Continuous laser is commonly applied as the light source in PDT. However, recent studies reported that intense pulsed light (IPL) could be an alternative option for PDT with an enhanced phototoxicity compared to the continuous laser used in 2D cell models. However, in vitro PDT studies on breast cancer usually ignored the effects of hormones. Hence, this study investigated the PDT efficacy using IPL via 3D breast cancer spheroids cultured in a simulated hormonal microenvironment.MethodThe MCF7 3D spheroids were cultured by the agarose-based liquid overlay method in a simulated hormonal microenvironment with estrogen and progesterone. After that, the spheroid size was measured and incubated with Hexyl-ALA at 4, 8, and 24 hours. The protoporphyrin IX (PpIX) generated from Hexyl-ALA was measured using flow cytometry and confocal microscopy. The PDT phototoxicity activated by IPL or continuous laser at 1, 2, and 4 J/cm2 were measured by MTT assay.Results &amp; DiscussionThe PpIX generation in 3D spheroids was optimal at 8 hrs incubation. At 50μM, 4J/cm 2 by IPL or continuous laser activation with both hormones, a 25% and 10% higher phototoxicity was obtained than no hormonal supplement counterparts.ConclusionThis study evident that IPL enhanced PDT efficacy on breast cancer 3D spheroids in a simulated hormonal microenvironment. More in-depth mechanistic studies using such model and light to investigate the relationship between hormonal changes and PDT in breast cancer deserve to be explored

Photodynamic action of LED-activated nanoscale photosensitizer in nasopharyngeal carcinoma cells

Background: Photodynamic therapy has been confirmed to an efficient therapeutic modality of malignant tumors. The aim of the present study was to explore the photodynamic action of LED-activated nanoscale photosensitizer- loading hypocrellin in nasopharyngeal carcinoma cells. Material/Methods: Nasopharyngeal carcinoma cell line CNE2 cells were subjected to photodynamic therapy with hypocrellinloaded nanophotosensitizer. The uptake of the nanophotosensitizer in the CNE-2 cells was measured using a spectrophotometer and photodynamic toxicity was investigated 18 h after LED radiation treatment. Apoptosis was determined using flow cytometry with propidum iodine staining, and nuclear staining with Hoechst 33258. Active caspase-3 in the CNE2 cells was evaluated using flow cytometry with phycoerythrin (PE)-conjugated anti-active caspase-3 antibodies. Results: The cellular uptake of the nanophotosensitizer in the CNE-2 cells reached optimal at 6 h. LED-activated nanophotosensitizer resulted in doseand light-dependent phototoxicity. Apoptotic rate 18 h after PDT increased to 34.32 ± 1.94% under the light energy of 1 J/cm2. Hoechest 33258 staining reinforced the findings above. Condensation of chromatin and nuclear fragmentations was found in many PDT-treated cells. The activated caspase-3 in the CNE2 cells significantly increased up to 43.90% when the CNE2 cells were exposed to the nanophotosensitizer for 6 h and then 1 J/cm2 irradiation. Conclusion: LED-activated nanophotosensitizer significantly killed the CNE2 cells and enhanced apoptosis and activated caspase-3 in the CNE2 cells. The hypocrellin-loaded nanophotosensitizer might be efficient photosensitizer and LED-activated nanophotosensitizer can be developed for treating nasopharyngeal carcinoma.link_to_subscribed_fulltex