Antitumor Effect of Sinoporphyrin Sodium-Mediated Photodynamic Therapy on Human Esophageal Cancer Eca-109 Cells

Arterial Adventitial Vasa Vasorum Density Reflects The Progression Of Unstable Plaques: A Retrospective Clinical Study

OBJECTIVE

Arterial adventitial vasa vasorum (AVV) plays an important role in the occurrence and development of atherosclerotic (AS) disease. AS is a systemic disease, and plaque is not only a local vascular event, but also occurs at multiple sites throughout the vascular bed. Currently, effective anti-AVV therapies are lacking. Therefore, we posed the following scientific questions: "does human carotid adventitial vasa vasorum density reflect plaque neovascularization and intimal-media hyperplasia in carotid?"; and "is it possible to reduce human AVV density by sonodynamic therapy (SDT)?"

METHODS

A retrospective study was conducted on 160 patients with carotid atherosclerosis. Duplex ultrasound scanning (DUS), contrast-enhanced ultrasound (CEUS), coronary angiography, and coronary CT angiography (CTA) were used for diagnosis and screening. Pearson correlation tests and Receiver operating characteristic (ROC) curve were used to analyze the relationships between AVV hyperplasia, vasa vasorum (VV) hyperplasia and the intima-media thickness (IMT). SDT was developed for the treatment of arterial AVV hyperplasia and AS plaques.

RESULTS

The presence of local AVV in carotid unstable plaques correlated with the echogenic properties of the carotid plaque and the extent of plaque progression; Furthermore local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with acute coronary syndrome (ACS) events; Local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with coronary artery stenosis. Notably, SDT reduced local AVV hyperplasia and shrank the plaques in human femoral and carotid atherosclerotic lesions.

CONCLUSIONS

The presence of AVV in human carotid arteries reflects the severity of carotid and coronary artery AS. Further, SDT can reduce the hyperplasia of local AVV in human femoral and carotid plaques.

Spotlight on porphyrins: Classifications, mechanisms and medical applications

Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are non-invasive treatment methods with obvious inhibitory effect on tumors and have few side effects, which have been widely concerned and explored by researchers. Sensitizer is the main factor in determining the therapeutic effect of PDT and SDT. Porphyrins, a group of organic compounds widespread in nature, can be activated by light or ultrasound and produce reactive oxygen species. Therefore, porphyrins as sensitizers in PDT have been widely explored and investigated for many years. Herein, we summarize the classical porphyrin compounds and their applications and mechanisms in PDT and SDT. The application of porphyrin in clinical diagnosis and imaging is also discussed. In conclusion, porphyrins have good application prospects in disease treatment as an important part of PDT or SDT, and in clinical diagnosis and imaging.

Precision Killing of Sinoporphyrin Sodium-Mediated Photodynamic Therapy against Malignant Tumor Cells

Photodynamic therapy (PDT) has significant advantages in the treatment of malignant tumors, such as high efficiency, minimal invasion and less side effects, and it can preserve the integrity and quality of the organs. The power density, irradiation time and photosensitizer (PS) concentration are three main parameters that play important roles in killing tumor cells. However, until now, the underlying relationships among them for PDT outcomes have been unclear. In this study, human malignant glioblastoma U-118MG and melanoma A375 cells were selected, and the product of the power density, irradiation time and PS concentration was defined as the total photodynamic parameter (TPP), in order to investigate the mechanisms of PS sinoporphyrin sodium (DVDMS)-mediated PDT (DVDMS-PDT). The results showed that the survival rates of the U-118MG and A375 cells were negatively correlated with the TPP value in the curve, and the correlation exactly filed an e-exponential function. Moreover, according to the formula, we realized controllable killing effects of the tumor cells by randomly adjusting the three parameters, and we finally verified the accuracy and repeatability of the formula. In conclusion, the establishment and implementation of a newly functional relationship among the PDT parameters are essential for predicting PDT outcomes and providing personalized precise treatment, and they are contributive to the development of PDT dosimetry.

Smart nanocomposite assemblies for multimodal cancer theranostics

Despite great strides in anticancer research, performance statistics of current treatment modalities remain dismal, highlighting the need for safe, efficacious strategies for tumour mitigation. Non-invasive fusion technology platforms combining photodynamic, photothermal and hyperthermia therapies have emerged as alternate strategies with potential to meet many of the unmet clinical demands in the domain of cancer. These therapies make use of metallic and magnetic nanoparticles with light absorbing properties, which are manipulated to generate either reactive cytotoxic oxygen species or heat for tumour ablation. Combination therapies integrating light, heat and magnetism-mediated nanoplatforms with the conventional approaches of chemotherapy, radiotherapy and surgery are emerging as precision medicine for targeted interventions against cancer. This article aims to compile recent developments of advanced nanocomposite assemblies that integrate multimodal therapeutics for cancer treatment. Amalgamation of various effective, non-invasive technological platforms such as photodynamic therapy (PDT), photothermal therapy (PTT), magnetic hyperthermia (MHT), and chemodynamic therapy (CDT) have tremendous potential in presenting safe and efficacious solutions to the formidable challenges in cancer therapeutics.

Determination of a novel photosensitizer sinoporphyrin sodium in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry

Sinoporphyrin sodium (DVDMS) is a new photosensitizer (PS) and it is used in photodynamic therapy (PDT) against tumor. In this paper, a simple, rapid and specific ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantitation of DVDMS in human plasma was developed. The analytes were extracted from plasma samples using liquid-liquid extraction (LLE) after addition of testosterone (internal standard) and chromatographed on an AQUITY UPLC Protein BEH C₄ column (50 × 2.1 mm, i.d. 1.7 μm) thermostatted at 40 °C with acetonitrile-water (0.1% formic acid and 0.1 mM K₂EDTA) as the gradient mobile phase at flow rate of 0.5 mL/min. The detection was performed on an API 5500 mass spectrometer coupled with electrospray ionization (ESI) source in positive mode. The multiple reactions monitoring (MRM) transitions of m/z 1143.6→563.2 and m/z 289.3→109.1 were used to quantify DVDMS and IS, respectively. The assay was validated over the concentration range of 30-3000 ng/mL. Precision and accuracy are in accordance with the generally accepted criteria for bioanalytical methods. The extraction recovery and the matrix effect were investigated. This method was successfully applied to pharmacokinetic (PK) study of DVDMS in Chinese patients with solid tumor after treated with DVDMS-PDT for the first time.

Sinoporphyrin sodium is a promising sensitizer for photodynamic and sonodynamic therapy in glioma

The aim of the present study was to explore the antitumor effects of sinoporphyrin sodium (DVDMS)‑mediated photodynamic therapy (PDT) and sonodynamic therapy (SDT) in glioma, and to reveal the underlying mechanisms. The uptake of DVDMS by U‑118 MG cells was detected by flow cytometry (FCM). A 630‑nm semiconductor laser and 1‑MHz ultrasound were used to perform PDT and SDT, respectively. Cell proliferation and apoptosis were evaluated using the Cell Counting Kit‑8 assay, FCM and Hoechst 33258 staining, respectively. Western blot analysis was used to detect protein expression and phosphorylation levels. BALB/c nude mice were used to establish a xenograft model of U‑118 MG cells. DVDMS was injected intravenously and PDT and SDT were performed 24 h later. An in vivo imaging system was used to evaluate the fluorescence of DVDMS, to measure tumor sizes, and to evaluate the therapeutic effects. The uptake of DVDMS by U‑118 MG cells was optimal after 4 h. PDT and SDT following DVDMS injection significantly inhibited the proliferation and increased apoptosis of glioma cells in vitro (P<0.05, P<0.01) respectively. In vivo, the fluorescence intensity of DVDMS was lower in the PDT and SDT groups compared with the DVDMS group, while tumor cell proliferation and weight were lower in the PDT and SDT groups than in the control group (P<0.05, P<0.01). However, there was no significant difference when laser, ultrasound or DVDMS were applied individually, compared with the control group. Hematoxylin and eosin staining suggested that both PDT and SDT induced significant apoptosis and vascular obstruction in cancer tissues. DVDMS‑mediated PDT and SDT inhibited the expression levels of proliferating cell nuclear antigen (PCNA) and Bcl‑xL, increased cleaved ‑caspase 3 levels, and decreased the protein phosphorylation of the PI3K/AKT/mTOR signaling pathway. Changes in the expression of PCNA, and Bcl‑xL and in the levels of cleaved‑caspase 3 were partly reversed by N‑acetyl‑L‑cysteine, a reactive oxygen species (ROS) scavenger. Similar results were obtained with FCM. DVDMS‑mediated PDT and SDT inhibited glioma cell proliferation and induced cell apoptosis in vitro and in vivo, potentially by increasing the generation of ROS and affecting protein expression and phosphorylation levels.

Antimicrobial effect of photodynamic therapy using sinoporphyrin sodium and 390-400 nm light-emitting diode on Porphyromonas gingivalis in vitro

This study aims to investigate the effect of antimicrobial photodynamic therapy (a-PDT) using a novel combination of sinoporphyrin sodium (DVDMS) and light-emitting diode (LED) with a wavelength of 390-400 nm on Porphyromonas gingivalis in vitro. Absorption spectrum of DVDMS was determined by spectrometer for selecting suitable wavelength light source. The uptake of DVDMS by P. gingivalis was evaluated according to fluorescence intensity detected by a spectrometer. Then effects of DVDMS alone, 390-400 nm LED alone, and photodynamic therapy produced by 10, 20, 40, and 80 μg/mL DVDMS and 390-400 nm LED on the suspension of P. gingivalis were evaluated by counting the number of colony forming units (CFU) after incubation. In the experiment, the LED illumination time was 30, 60, 90, 120, 180, 240, and 360 s, respectively, and the corresponding energy density was 1, 2, 3, 4, 6, 8, and 12 J/cm², respectively. According to the absorption spectrum of DVDMS, the 390-400-nm light emitted by the LED was selected as the light source. The fluorescence intensity of DVDMS on P. gingivalis increased significantly at 5 min, and with the extension of time, it decreased at 30 min. DVDMS alone did not produce a significant toxicity on P. gingivalis compared with PBS (p = 0.979). While 390-400 nm LED alone had a certain bactericidal effect on P. gingivalis, the bactericidal effect was more obvious as the light dose increased (p < 0.001). The effect of a-PDT produced by 20, 40, and 80 μg/mL DVDMS and 390-400 nm LED were significantly better than that of 390-400 nm LED alone (p < 0.05). Both DVDMS concentration and light dose could enchance the bactericidal effect. The strongest photo-killing effect was generated by 80 μg/mL DVDMS with 360 s illumination (energy density is 12 J/cm²), and the log reduction of bacteria was 5.69 ± 1.70. a-PDT using the combination of DVDMS with 390-400 nm LED shows promise as a new treatment modality for pathogens elimination in periodontal therapy.

Sinoporphyrin sodium, a novel sensitizer for photodynamic and sonodynamic therapy

Sinoporphyrin sodium (DVDMS) is a novel sensitizer discovered by Professor Fang Qi-Cheng and widely used in photodynamic (PDT) and sonodynamic therapy (SDT). We searched databases including PubMed, Web of Science, CNKI, etc. for system review of its progress. We found that, both DVDMS-PDT and -SDT had been proven effective for inhibiting tumor growth and mechanisms involved reactive oxygen species, autophagy, and mitochondrial apoptosis pathways. Material advances enhanced antitumor effects and expanded its application. The safety of DVDMS in animals was evaluated, and metabolic parameters were uncovered. Additionally, DVDMS-PDT also exhibited therapeutic effects on non-neoplastic diseases like psoriasis and bacterial infections. Two phase I clinical trials of DVDMS have been documented, but recruitments had still not been completed. In conclusion, DVDMS is a promising sensitizer for both PDT and SDT; however, there are some shortcomings in previous studies like inconsistent treatment parameters, which need systematic assessments in future. Moreover, more mechanisms such as the role of autophagy need to be discovered. Further evidence of the safety and effectiveness of new materials are needed, and the application in non-neoplastic diseases like actinic keratosis and fungal infection deserves further development. Above all, promoting its clinical applications is the most important goal.

The Application of DVDMS as a Sensitizing Agent for Sono-/Photo-Therapy

Both photodynamic therapy (PDT) and sonodynamic therapy (SDT) are fast growing activated therapies by using light or ultrasound to initiate catalytic reaction of sensitizing agents, showing great potentials in clinics because of high safety and noninvasiveness. Sensitizers are critical components in PDT and SDT. Sinoporphyrin sodium (DVDMS) is an effective constituent derived from Photofrin that has been approved by FDA. This review is based on previous articles that explore the applications of DVDMS mediated photodynamic/sonodynamic cancer therapy and antimicrobial chemotherapy. Researchers utilize different cell lines, distinct treatment protocols to explore the enhanced therapeutic response of neoplastic lesion. Moreover, by designing a series of nanoparticles for loading DVDMS to improve the cellular uptake and antitumor efficacy of PDT/SDT, which integrates diagnostics into therapeutics for precision medical applications. During the sono-/photo-activated process, the balance between oxidation and antioxidation, numerous signal transduction and cell death pathways are also involved. In addition, DVDMS mediated photodynamic antimicrobial chemotherapy (PACT) can effectively suppress bacteria and multidrug resistant bacteria proliferation, promote the healing of wounds in burn infection. In brief, these efficient preclinical studies indicate a good promise for DVDMS application in the activated sono-/photo-therapy.

miR-7112-3p targets PERK to regulate the endoplasmic reticulum stress pathway and apoptosis induced by photodynamic therapy in colorectal cancer CX-1 cells

BACKGROUND

Colorectal cancer (CRC) is the third most common malignant tumor worldwide. Photodynamic therapy (PDT) is an emerging modality for the treatment of solid tumors. Sinoporphyrin sodium (DVDMS) is a new photosensitizer with good therapeutic killing effects on cancer cells. Recent findings have shown that microRNAs play important roles in many biological processes. However, the functions of microRNAs in DVDMS-induced PDT remain largely unclear.

MATERIALS AND METHODS

Proteins involved in endoplasmic reticulum (ER) stress and apoptosis of CX-1 cells treated with DVDMS-PDT were examined by Western blotting and cell viability assays. 15 candidate miRNAs targeting RNA-dependent protein kinase-like ER kinase (PERK) were screened and verified using the TargetScan, miRWalk and miRDB databases. The downstream pathways of candidate miRNAs with high scores were studied by cell transfection, qRT-PCR, Western blotting and dual-luciferase reporter assays. The subcellular location of DVDMS was confirmed by laser confocal microscopy.

RESULTS

DVDMS-PDT induced apoptosis via elevated ER stress and activation of the PERK/ATF4/CHOP/caspase cascade pathway in CX-1 cells. The endoplasmic reticulum was involved in the subcellular accumulation of DVDMS in CX-1 cells. Dual-luciferase reporting experiment confirmed that a direct crosslinking between miR-7112-3p and PERK. In addition, miR-7112-3p was highly expressed in CRC tissues compared with peripheral tissues.

CONCLUSION

Our work showed that miR-7112-3p directly targeted PERK and further regulated PERK/ATF4/CHOP/caspase cascade pathway, resulting in enhanced apoptosis in CX-1 cells treated with DVDMS-PDT.

Sun exposure to the eyes: predicted UV protection effectiveness of various sunglasses

The aim of this study was to assess solar ultraviolet radiation (UVR) doses received by the eyes in different exposure situations, and to predict the sun protection effectiveness provided by various styles of sunglasses at facial, periorbital, and ocular skin zones including the cornea and accounting for different head positions. A 3D numeric model was optimized to predict direct, diffuse and reflected erythemally weighted UVR doses received at various skin zones. Precisely defined facial, periorbital, and ocular skin zones, sunglasses (goggles, medium-, and large-sized sunglasses) and three head positions were modeled to simulate daily (08:00-17:00) and midday (12:00-14:00) UVR doses. The shading from sunglasses' frame and lenses' UVR transmission were used to calculate a predictive protection factor (PPF [%]). Highest ocular daily UVR doses were estimated at the uncovered cornea (1718.4 J/m²). Least sun protection was provided by middle-sized sunglasses with highest midday dose at the white lateral (290.8 J/m²) and lateral periorbital zones (390.9 J/m²). Goggles reached almost 100% protection at all skin zones. Large-sized sunglasses were highly effective in winter; however, their effectiveness depended on diffuse UVR doses received. In "looking-up" head positions highest midday UVR doses were received at the unprotected cornea (908.1 J/m²), totally protected when large-sized sunglasses are used. All tested sunglass lenses fully blocked UVR. Sunglasses' protection effectiveness is strongly influenced by geometry, wearing position, head positions, and exposure conditions. Sunglasses do not totally block UVR and should be combined with additional protection means. 3D modeling allows estimating UVR exposure of highly sensitive small skin zones, chronically exposed and rarely assessed.

Photodynamic Therapy Enhanced the Antitumor Effects of Berberine on HeLa Cells

In this study we investigated the antineoplastic effects of Berberine (BBR)-mediated photodynamic therapy (PDT) on HeLa cells and its related mechanisms. The CCK-8 assay and flow cytometry were used to evaluate the proliferation and apoptosis of cells respectively. In addition, changes in protein expression levels were assessed using western blot. BBR at dose of 10 mg/kg was injected intraperitoneally to mice with tumors and PDT treatments were performed 24 hours later. In vivo imaging systems were used to evaluate the fluorescence of BBR. In vitro, PDT significantly enhanced the effects of BBR on inducing cell apoptosis and inhibiting proliferation. The in vivo results showed that the fluorescence intensity in the PDT group was decreased compared with that in the BBR group. Tumor weights and tumor size in the PDT group were less than those in the control group; however, when BBR was applied without PDT, no significant differences were observed between the BBR and control group. The results of western blot showed that PDT enhanced the inhibitory effects of BBR on the mammalian target of rapamycin (mTOR) signaling pathway, that may partly explain the potential underlying mechanisms.

Apoptosis and autophagy induced by DVDMs-PDT on human esophageal cancer Eca-109 cells

BACKGROUND

Esophageal cancer is a common gastrointestinal cancer. About 300,000 people die from esophageal cancer every year in the world. Photodynamic therapy (PDT) has attracted attention as a feasible cancer therap for this diagnosis. Sinoporphyrin sodium (DVDMs) is a novel sensitizer isolated from photofrin. In this study, we aimed to investigate the effects of DVDMs mediated photodynamic therapy and the possible mechanism on human esophageal cancer Eca-109 cells.

METHODS

Cell viability was measured by MTT assay and cell apoptosis was determined by Annexin V-PE/7-AAD and western blot. MDC staining and western blot were used to evaluate cell autophagy. The production of intracellular reactive oxygen species (ROS) was detected by flow cytometry. The expression of MAPK and HO-1 were detected by western blot.

RESULTS

DVDMs-PDT decreased cell viability and induced cell apoptosis and autophagy. Autophagy inhibition reduced cell apoptosis triggered by DVDMs-PDT in Eca-109 cells. Generation of ROS was detected in DVDMs-PDT group. p38MAPK, JNK and HO-1 were activated after PDT treatment and the activation were reversed by adding ROS scavenger NAC.

CONCLUSIONS

Our studies demonstrated that DVDMs-PDT induced apoptosis and autophagy in Eca-109 cells. DVDMs-PDT induced ROS generation in Eca-109 cells, and the generation of ROS activated p38MAPK and JNK. Activation of p38MAPK and JNK may be involved in PDT-induced apoptosis.

Safety evaluation of repeated intravenous infusion of sinoporphyrin with and without PDT in rats

Photodynamic therapy (PDT) is a promising antineoplastic modality in the oncology field. We assessed the safety of repeated intravenous administrations of sinoporphyrin, a porphyrin derivative, with and without illumination in rats. Toxicokinetic studies of single and multiple administrations of sinoporphyrin were also carried out. Sprague-Dawley rats were randomly assigned to the dark-toxicity and PDT groups. Animals in the dark toxicity group received an i.v. infusion of sinoporphyrin at 3 doses: 2 mg kg^-1, 6 mg kg^-1, and 18 mg kg^-1. The PDT group included 2 doses of sinoporphyrin (2 mg kg^-1 and 18 mg kg^-1), and the rats received 60 J of 630 nm laser illumination 24 h after photosensitizer infusion. The treatments were repeated every 7 days for 5 cycles and were followed by a 14-day recovery period. Systematic analyses were conducted at the end of treatment and recovery periods. Blood samples were obtained 5 min, 30 min, 2 h, 8 h, 24 h, 48 h, 72 h, and 96 h after the first and fifth treatments for toxicokinetic studies. Sinoporphyrin-PDT led to the death of one out of 270 rats; the dead animal had been treated with 18 mg kg^-1 sinoporphyrin and died at the end of the fifth PDT treatment. Liver injury, the primary toxicity observed in the study, was identified using biochemical tests, necropsy, and histopathology. Elevated white blood cell and neutrophil counts were found in the rats in both the dark toxicity and PDT groups. Skin lesions at the illumination site were obvious in the PDT group. Pigment deposits were detected in multiple organs such as the liver, spleen, lymph nodes, and ovaries in the 6 mg kg^-1 and 18 mg kg^-1 groups. No other abnormalities were observed. The toxicokinetic parameters of single and multiple sinoporphyrin administrations were calculated and compared. Repeated sinoporphyrin administrations both alone and in combination with laser illumination were tolerable, and all toxicities were transient. The no observed adverse effect level (NOAEL) for repeated sinoporphyrin administration and sinoporphyrin-PDT was 6 mg kg^-1 and 2 mg kg^-1, respectively. Further studies are warranted.

Efficiency of ocular UV protection by clear lenses

Ocular UV doses accumulate all-day, not only during periods of direct sun exposure. The UV protection efficiency of three clear lenses was evaluated experimentally, validated by simulation, and compared to non-UV protection: a first spectacle lens with a tailored UV absorber, a second spectacle lens, minimizing UV back reflections, as well as a third spectacle lens, combining both. A tailored UV-absorber efficiently reduced overall UV irradiance to 7 %, whereas reduction of back-reflections still left UV irradiance at 42 %. Thus, clear lenses with a tailored UV absorber efficiently protect the eye from UV, supplementing sun glasses wear to an all-day protection scenario.

Photophysical properties of sinoporphyrin sodium and explanation of its high photo-activity

Sinoporphyrin sodium (DVDMS) is a novel photosensitizer with high photodynamic therapy (PDT) effect. Reasons for its high photo-activity were investigated according to the study of photophysical characteristics of DVDMS. Extinction coefficients ([Formula: see text] of DVDMS at 405 nm and 630 nm are 4.36 × 105 and 1.84 × 104 M[Formula: see text].cm[Formula: see text]; fluorescence quantum yield ([Formula: see text] is 0.026; quantum yield of lowest triplet state formation is 0.94 and singlet oxygen quantum yield ([Formula: see text] is 0.92. Although [Formula: see text] of DVDMS is only 10% higher than that of Photofrin[Formula: see text] (0.83), the extinction coefficient of DVDMS at 630 nm is 10-fold greater than that of Photofrin[Formula: see text]. This leads to its higher singlet oxygen generation efficiency ([Formula: see text]. The higher [Formula: see text] of DVDMS can result in an effective reduction of dosage (1/10 of Photofrin[Formula: see text] reaching the same cytotoxic effect as Photofrin[Formula: see text]. Even though [Formula: see text] is approximately equal to that of Photofrin[Formula: see text], brightness ([Formula: see text] of DVDMS is 10-fold greater than that of Photofrin[Formula: see text] because of the 10-fold greater extinction coefficient. Thus, fluorescence diagnosis ability of 0.2 mg/kg DVDMS is comparable to that of 2 mg/kg Photofrin[Formula: see text] used in PDT. Overall, the 10-fold greater extinction coefficients are responsible for the high brightness and singlet oxygen generation efficiency of DVDMS.

Photodynamic action of palmatine hydrochloride on colon adenocarcinoma HT-29 cells

Palmatine hydrochloride (PaH) is a natural active compound from a traditional Chinese medicine (TCM). The present study aims to evaluate the effect of PaH as a new photosensitizer on colon adenocarcinoma HT-29 cells upon light irradiation. Firstly, the absorption and fluorescence spectra of PaH were measured using a UV-vis spectrophotometer and RF-1500PC spectrophotometer, respectively. Singlet oxygen ((1)O2) production of PaH was determined using 1, 3-diphenylisobenzofuran (DPBF). Dark toxicity of PaH was estimated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cellular uptake of PaH in HT-29 cells was detected at different time intervals. Subellular localization of PaH in HT-29 cells was observed using confocal laser fluorescence microscopy. For photodynamic treatment, HT-29 cells were incubated with PaH and then irradiated by visible light (470nm) from a LED light source. Photocytotoxicity was investigated 24h after photodynamic treatment using MTT assay. Cell apoptosis was observed 18h after photodynamic treatment using a flow cytometry with Annexin V/PI staining. Results showed that PaH has an absorption peak in the visible region from 400nm to 500nm and a fluorescence emission peak at 406nm with an excitation wavelength of 365nm. PaH was activated by the 470nm visible light from a LED light source to produce (1)O2. Dark toxicity showed that PaH alone treatment had no cytotoxicity to HT-29 cancer cells and NIH-3T3 normal cells after incubation for 24h. After incubation for 40min, the cellular uptake of PaH reached to the maximum and PaH was located in mitochondria. Photodynamic treatment of PaH demonstrated a significant photocytotoxicity on HT-29 cells. The rate of cell death increased significantly in a PaH concentration-dependent and light dose-dependent manner. Further evaluation revealed that the early and late apoptotic rate of HT-29 cells increased remarkably up to 21.54% and 5.39% after photodynamic treatment of PaH at the concentration of 5μM and energy density of 10.8J/cm(2). Our findings demonstrated that PaH as a naturally occurring photosensitizer has potential in photodynamic therapy on colon adenocarcinoma.

Structure-activity relationship study of anticancer thymidine-quinoxaline conjugates under the low radiance of long wavelength ultraviolet light for photodynamic therapy

Thymidine quinoxaline conjugate (dT-QX) is a thymidine analog with selective cytotoxicity against different cancer cells. In this study, the structure activity relationship study of dT-QX analogs was carried out under the low radiance of black fluorescent (UVA-1) light. Significantly enhanced cytotoxicity was observed under UVA-1 activation among analogs containing both thymidine and quinoxaline moieties with different length of the linker, stereochemical configuration and halogenated substituents. Among these analogs, the thymidine dichloroquinoxaline conjugate exhibited potent activity under UVA-1 activation as the best candidate with EC50 at 0.67 μM and 1.3 μM against liver and pancreatic cancer cells, respectively. In contrast, the replacement of thymidine moiety with a galactosyl residue or the replacement of quinoxaline moiety with a fluorescent pyrenyl residue or a simplified diketone structure resulted in the full loss of activity. Furthermore, it was revealed that the low radiance of UVA-1 at 3 mW/cm(2) for 20 min was sufficient enough to induce the full cytotoxicity of thymidine dichloroquinoxaline conjugate and that the cytotoxic mechanism was achieved through a rapid and steady production of reactive oxygen species.

The anti-esophageal cancer cell activity by a novel tyrosine/phosphoinositide kinase inhibitor PP121

Here we explored the potential effect of PP121, a novel dual inhibitor of tyrosine and phosphoinositide kinases, against human esophageal cancer cells. We showed that PP121 exerted potent cytotoxic effect in primary (patient-derived) and established (Eca-109, TE-1 and TE-3 lines) esophageal cancer cells, possibly through activating caspase-3-dependnent apoptosis. PP121 was, however, non-cytotoxic to the normal human esophageal epithelial cells (EECs). At the molecular level, we showed that PP121 blocked Akt-mTOR (mammalian target of rapamycin) activation in esophageal cancer cells, which was restored by introducing a constitutively-active Akt (CA-Akt). Yet, CA-Akt only partly inhibited cytotoxicity by PP121 in Eca-109 cells. Importantly, we showed that PP121 inhibited nuclear factor kappa B (NFκB) signaling activation in esophageal cancer cells, which appeared independent of Akt-mTOR blockage. In vivo, oral administration of PP121 remarkably inhibited Eca-109 xenograft growth in nude mice, and significantly improved mice survival. Further, the immunohistochemistry (IHC) and Western blot assays analyzing xenografted tumors showed that PP121 inhibited Akt-mTOR and NFκB activations in vivo. Together, we demonstrate that PP121 potently inhibits esophageal cancer cells in vitro and in vivo, possibly through concurrently inhibiting Akt-mTOR and NFκB signalings.

Analysis of the in vivo and in vitro effects of photodynamic therapy on breast cancer by using a sensitizer, sinoporphyrin sodium

Photodynamic therapy (PDT) is an emerging theranostic modality for various cancers and diseases. Photosensitizers are critical components for PDT. Sinoporphyrin sodium, referred to as DVDMS, is a newly identified photosensitizer that was isolated from Photofrin. Here, we evaluated the effects of DVDMS-mediated PDT (DVDMS-PDT) on tumor cell proliferation and metastasis in the highly metastatic 4T1 cell line and a mouse xenograft model. DVDMS-PDT elicited a potent phototoxic effect in vitro, which was abolished using the reactive oxygen species (ROS) scavenger N-acetylcysteine. In addition, DVDMS-PDT effectively inhibited the migration of 4T1 cells in scratch wound-healing and transwell assays. Using an in vivo mouse model, DVDMS-PDT greatly prolonged the survival time of tumor-bearing mice and inhibited tumor growth and lung metastasis, consistent with in vitro findings. PDT with DVDMS had a greater anti-tumor efficacy than clinically used Photofrin. Moreover, preliminary toxicological results indicate that DVDMS is relatively safe. These results suggest that DVDMS is a promising sensitizer that warrants further development for use in cancer treatment with PDT or other sensitizing agent-based therapies.

A safety study of a novel photosensitizer, sinoporphyrin sodium, for photodynamic therapy in Beagle dogs

Sinoporphyrin sodium (DVDMS) based photodynamic therapy (PDT) showed skin phototoxicity in Beagle dogs, did not accumulate in blood plasma, and had an effect on the immune organs and the liver.