5-氨基乙酰丙酸光动力杀伤人鼻咽癌细胞株的实验研究

目的 探讨5-氨基乙酰丙酸(5-ALA)光动力学效应(PDT)杀伤人鼻咽癌细胞株CNE2的可能性.方法 对培养的CNE2分别加入不同浓度的5-ALA(0.01、0.05、0.10、0.25、0.5、1.0、2.0、4.0mmol/L)孵育4h,予波长630nm的半导体激光照射,照射能量密度分别为20、10、5、2J/cm2,继续孵育6、12、24h,用四唑盐比色法分别测定细胞存活率.结果 5-ALA-PDT能有效杀伤人鼻咽癌CNE2细胞,其杀伤程度与照射后孵育时间、5-ALA浓度和激光剂量呈正相关(P＜0.01).激光照射后12h,激光能量为20J/cm2,5-ALA浓度为0.5mmol/L时,其杀伤作用最明显.结论 体外培养CNE2细胞对5-ALA介导的PDT敏感.     

Efficacy of photodynamic therapy with 5-aminolevulinic acid for the treatment of cervical high-grade squamous intraepithelial lesions with high-risk HPV infection: A retrospective study

BackgroundThe current principle of clinical management of cervical high-grade squamous intraepithelial lesion(HSIL) is surgical excision. However excisional procedures of the uterine cervix may have a negative impact on fertility. Topical photodynamic therapy(PDT) is a non-invasive and selective tissue destruction. We investigated the clinical efficacy of PDT for cervical HSIL with high-risk human papilloma virus(HPV) infection.MethodsA retrospective study consisting of 96 patients aged 20–50 years with a histologically confirmed cervical HSIL with high-risk HPV infection from July 2018 to June 2022 was carried out. Patients were treated with six times of 20% 5-aminolevulinic acid photodynamic therapy (5-ALA PDT) at intervals of 7–14 days. Three months after treatment, the effect was evaluated through HPV typing and colposcopy directed biopsy. Six and twelve months after treatment, TCT and HPV tests were carried out.ResultsThree months after 5-ALA PDT treatment, among 96 HSIL with high-risk HPV infection patients, the total lesion regression rate was 89.58%(86/96), and the HPV clearance rate was 79.17 % (76/96) at 3 months follow-up. At 6 and 12 months follow-up, the patients who was HSIL pathological regression and negative HPV at 3 months follow-up continued negative results in both TCT and HPV. All patients with ineffective 5-ALA PDT treatment had persistent HPV infections. There was no significant difference in the HSIL regression rate and HPV clearance rate among different age groups. The main side effects of PDT were abdominal pain and increased vaginal secretions. Univariate analysis showed that the different severity of cervical cytology was associated with lesion regression rate in 5-ALA PDT treatment. The HSIL regression rate of TCT<ASC-H was higher than that of TCT≧ASC-H(94.59% vs 72.72%; P<0.01).Multicentric lesions,the proportion of visible lesion size in ectocervical size≥24.59%, size of visible lesion ≥1.23cm² and maximum linear length of visible lesion ≥0.90cm were risk factors of HSIL persistence after 5-ALA PDT treatment (P<0.05).Conclusion5-ALA PDT can be a safe and efficient treatment for cervical HSIL who wish to preserve fertility. 5-ALA PDT did not appear to create cervical damage and have negligible side effects. But we need evaluate the type of transformation zone, the visible lesion size, the location of lesion,baseline status of TCT and histological results before 5-ALA PDT treatment.     

Evaluation of 5-aminolevulinic acid-mediated photodynamic therapy on cervical low-grade squamous intraepithelial lesions with high-risk HPV infection

BackgroundThe treatment options for low‐grade squamous intraepithelial neoplasia (LSIL) of the cervix with high-risk HPV infection have not been standardized. Studies show that photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (ALA-PDT) might be effective. In this retrospective study, the clinical efficacy and safety of ALA-PDT in the treatment of LSIL were evaluated.MethodsALA-PDT was performed in 55 LSIL patients aged 21–45 years who also showed high-risk HPV infection and cervical ectropion. HPV test, cytology, colposcopy and pathology were examined before and after treatment. Meanwhile, PDT-related symptoms and adverse reactions were also reviewed.ResultsAt 6-month follow-up after PDT, except for 5 patients who showed the persistence of LSIL lesions, the pathological regression ratio of 90.1% (50/55) was achieved. No HPV-DNA was detected in exfoliated cervical cells in 81.8% (45/55) patients. Among them, the HPV clearance ratio of I Degree cervical ectropion was 96.2%, significantly higher than that of II Degree (70.8%) and III Degree (60%). Significant shrunk of cervical ectropion and reduction of vaginal secretions after PDT were seen in 78.0% patients.ConclusionALA-PDT is a safe and effective therapeutic option for patients of reproductive age who suffer from LSIL with high-risk HPV infection and cervical ectropion.     

Dihydroartemisinin administration improves the effectiveness of 5-aminolevulinic acid-mediated photodynamic therapy for the treatment of high-risk human papillomavirus infection

Aims and BackgroundHigh-risk human papillomavirus (HR-HPV) infection has been confirmed to be highly related to diseases such as Bowenoid papulosis, cervical cancer, and cervical intraepithelial neoplasia. 5-aminolevulinic acid-mediated PDT (ALA-PDT) has been used in a variety of HR-HPV infection-related diseases. Dihydroartemisinin (DHA) is one of artemisinin derivatives, and has inhibitory effects on a variety of cancer cells. For now, there is no published study focusing on the combination use of ALA-PDT with DHA to improve clinical efficacy of HR-HPV infection-related diseases. So in this study, we will examine the effectiveness of combined treatment of ALA-PDT and DHA for HR-HPV infection as well as its underlying mechanism.MethodsThe human cervical cancer cell line HeLa (containing whole genome of HR-HPV18) was treated with ALA-PDT or/and DHA, and cell viability, long proliferation, ROS production and apoptosis were evaluated by CCK8, colony-forming assay, immunofluorescence and flow cytometry, respectively. The protein expression of NF-κB-HIF-1α-VEGF pathway and NRF2-HO-1 pathway was examined by western blot.ResultsThe results showed that DHA could enhance the effect of ALA-PDT on cell viability long proliferation, ROS production and apoptosis in HeLa cells. We also found that DHA inhibited NF-κB-HIF-1α-VEGF pathway which was activated by ALA-PDT. Besides, ALA-PDT combined with DHA activated NRF2-HO-1 pathway.ConclusionAlthough the NRF2 - NO-1 pathway as a resistance mechanism remains unresolved, DHA has the potential to enhance the effect of ALA-PDT for HPV infection-related diseases through inhibiting NF-κB - HIF-1α - VEGF pathway.     

Effect of 5-aminolevulinic acid photodynamic therapy on keratinocyte proliferation and apoptosis in condyloma acuminatum

BackgroundThe effect of 5-aminolevulinic acid photodynamic therapy on keratinocyte proliferation and apoptosis in condyloma acuminatum tissues was evaluated.MethodsAn immunohistochemical method and TdT-mediated dUTP nick end labeling were performed to detect the positive expression of the keratinocyte proliferation-related gene Ki-67 and apoptosis, respectively, in condyloma acuminatum tissues.ResultsOf 52 cases, 44 showed positive expression of Ki-67 in condyloma acuminatum keratinocytes before the treatment, with a positive expression rate of 84.62% (44/52), an expression strength of mostly ++ − +++, and a Ki-67 proliferation index of 80.26 ± 5.07%. After treatment, 22 cases showed positive expression of Ki-67 in condyloma acuminatum keratinocytes, with a positive expression rate of 42.31% (22/52), an expression strength of mostly − − ++, and a proliferation index of 42.67 ± 3.06%. The differences in the positive expression rate, expression strength, and proliferation index in the before- and after-treatment groups were statistically significant (χ² = 20.070, P < 0.001). For visible apoptotic cells in condyloma acuminatum keratinocytes before the 5-aminolevulinic acid photodynamic treatment, the expression strength was mostly + − ++, and the average apoptotic index was 13.94 ± 2.35%; after treatment, the expression strength was mostly ++ − +++, and the average apoptotic index was 73.88 ± 7.65%; the difference in the apoptotic index between the before and after treatment groups was statistically significant (P < 0.001).Conclusion5-Aminolevulinic acid photodynamic therapy can inhibit the proliferation and promote the apoptosis of keratinocytes, and represents an effective mechanism for treating condyloma acuminatum.     

Evaluation of the efficacy and safety of 5-aminolevulinic acid-mediated photodynamic therapy in women with high-risk HPV persistent infection after cervical conization

ObjectiveTo evaluate the efficacy and safety of photodynamic therapy (PDT) in women with high-risk human papillomavirus (hr-HPV) persistent infection after cervical conization, including loop electrosurgical excision procedure (LEEP) and cold knife conization (CKC).Materials and methodsThe clinicopathological and follow-up data of 76 women with hr-HPV persistent infection after cervical conization (54 cases with LEEP and 22 cases with CKC) were collected. All the women in this group met these criteria: postoperative pathological diagnosis of LEEP/CKC showed high grade squamous intraepithelial lesions (HSIL) with negative incisal margin, hr-HPV persistent infection after LEEP/CKC ≥ 1 year, colposcopy and histopathology showed no intraepithelial lesions before PDT, and 5-aminolaevulinic acid (5-ALA) as photosensitizer treating for 6 times with an interval of 7-10 days. The above patients were followed up 6 months and 12 months after PDT, and the follow-up contents included Roche Cobas HPV classification test, cytology, colposcopy, and pathological examinations. HPV negative conversion rate is an index to evaluate the efficacy of PDT. In addition, we also assessed the safety of PDT.ResultsSix months after PDT, the overall HPV clearance rate was 59.21% (45/76). The HPV negative conversion rates in patients ≤ 50 years old group and > 50 years old group were 68.52% (37/54) and 36.36% (8/22), respectively (P=0.009). But there was no significant difference in HPV clearance rate between the HPV16/18 infection group and other hr-HPV infection group (P=0.3326). 12 months after PDT, 1 case underwent hysterectomy because of progression to HSIL, and 7 cases lost follow-up. The overall HPV clearance rate was 88.24% (60/68). The negative conversion rates of HPV16/18 and other hr-HPV infection groups were 76.00% (19/25) and 95.35% (41/43), respectively (P=0.0458). However, the HPV negative conversion rate was not correlated with the patient's age (P=0.2383). The adverse reactions after PDT were mild, mainly manifested as increased vaginal secretions or burning/tingling.ConclusionsPhotodynamic therapy could be an effective treatment for patients with hr-HPV persistent infection after cervical conization and it could promote the negative conversion of hr-HPV and prevent the recurrence progression of cervical intraepithelial neoplasia (CIN) after LEEP/CKC.     

The effect of local photodynamic therapy with 5-aminolevulinic acid in the treatment of vaginal intraepithelial lesions with high-risk HPV infection

BackgroundRecent data has shown increased rate of vaginal intraepithelial neoplasia (VAIN) in younger individuals. Traditional VAIN treatments exert adverse effects on the anatomy and functions of the vagina. Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a novel, non-invasive targeted therapy for intraepithelial lesions. Here, we aimed to investigate the efficacy and safety of ALA-PDT in VAIN with high-risk HPV (HR-HPV) infection.MethodsThis study enrolled a total of 82 HR-HPV-positive women diagnosed with VAIN, who were receiving ALA-PDT. The effect of ALA-PDT was evaluated using HPV genotyping and Thinprep cytologic test (TCT). Besides, colposcopy directed biopsies were performed in all patients at 3-month follow-up, and in patients with positive HR-HPV and/or abnormal TCT results during the follow-up period.ResultsOur data showed that the HPV clearance rate was 53.7% (44/82) at 6-month follow-up and 67.1% (55/82) at 12-month follow-up. Patients with HPV16/18 combined with other HR-HPV (HPV16/18 & other HR-HPV) infection, those with a history of hysterectomy and/or older age were had significantly lower HPV clearance rate. Besides, the lesion complete remission (CR) rate was 90.2% (74/82). These results show that HPV16/18 & other HR-HPV infection was associated with significantly lower CR rates. Throughout the follow-up, 2 cases had persistent lesions (2.4%), 6 cases had partial remission (7.3%), 2 cases recurred (2.7%) but none of the patients had disease progression.ConclusionsTaken together, our data showed that ALA-PDT is an effective, safe, and alternative treatment for VAIN patients with HR-HPV infection. However, the ALA-PDT efficacy was relatively poor in patients with older age, HPV16/18 & other HR-HPV infection and/or those with a history of hysterectomy.     

Effect of 5-aminolevulinic acid photodynamic therapy on Candida albicans biofilms: An in vitro study

BackgroundIn this study, the photoinactivation of 5-aminolevulinic acid (ALA) has been investigated on Candida albicans biofilms in vitro.MethodsAfter culture and proliferation of Candida albicans biofilms in vitro, the metabolic activity was confirmed using XTT reduction assay. Then, the suitable incubation time and concentration of ALA were determined by measuring PpIX accumulation quantities. Photosensitivity of the biofilms treated with ALA solution was studied in optical doses of 50, 100, 200 and 300 J/cm² while light irradiation was applied by a red light semiconductor. Finally, rapid immunofluorescence staining method using the LIVE/DEAD FungaLight Yeast Viability Kit and XTT assay were conducted to visualize and quantify the antifungal effect of ALA-PDT on Candida albicans biofilms.ResultsA 5 h incubation time and 15 mM ALA concentration were determined for this study. Photoinactivation of ALA-PDT on Candida albicans biofilms showed a significant increase of protoporphyrin IX (PpIX) in the biofilms. The metabolic activity of Candida albicans biofilms tread with ALA-PDT confirmed the inhibition efficacy compared with control groups. Upon radiation at 300 J/cm², cells in Candida albicans biofilms were 74.45% inhibited.ConclusionsPpIX can be absorbed in biofilm-grown Candida albicans in vitro and under appropriate parameters, photochemistry can be triggered by light in combination with ALA and inhibits Candida albicans biofilms effectively.     

Enhancing the efficiency of 5-aminolevulinic acid-mediated photodynamic therapy using 5-fluorouracil on human melanoma cells

Background5-Aminolevulinic acid-mediated photodynamic therapy (ALA–PDT) is an effective and noninvasive modality for treatment of several types of non-melanoma skin cancers. This in-vitro study attempted to know whether the killing effect of ALA–PDT on the human melanoma cells (Mel-Rm cell line) could be increased by the presence of 5-fluorouracil (5-FU).MethodsTo evaluate the effect of ALA–PDT in combination with 5-FU on viability of human melanoma Mel-Rm cells, the cells incubated with 5-ALA and 5-FU for 3 h in nontoxic concentrations, and subsequently illuminated with a 630 nm light-emitting diode array. The cells viability and cytotoxicity determined by mitochondrial activity and lactate dehydrogenase assays.ResultsCombination of ALA–PDT and 5-FU (FU–ALA–PDT) showed a considerable growth inhibition according to the results of MTT assay compared to ALA–PDT. The results of LDH assay also showed a cytotoxicity effect in ALA–PDT; however, the FU–ALA–PDT showed no significantly enhancement in cytotoxicity compared to ALA–PDT using LDH assay.ConclusionThe Mel-Rm cells incubation with 5-FU before PDT enhances the efficiency of 5-Aminolevulinic acid-mediated photodynamic therapy.     

Effects of 5-aminolevulinic acid photodynamic therapy on TLRs in acne lesions and keratinocytes co-cultured with P. acnes

ObjectiveTo investigate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) on the expression of Toll like receptors (TLRs) in human keratinocytes and its role in acne treatment.MethodsTLR2 and TLR4 expression in acne lesions before and after ALA-PDT were examined by immunohistochemical assay. Primary keratinocytes were obtained from acne lesions, co-cultured with P. acnes and then treated with ALA-PDT using red or blue LED. Cytokines production were examined by ELISA, TLR2 and TLR4 gene expression by real-time PCR, and TLR2 and TLR4 protein expression by Western-blot assay.ResultsThe overexpression of TLR2 and TLR4 in acne lesion were detected, which became negative or weaker after ALA-PDT. The infection of P. acnes in keratinocytes could significantly increase the levels of early inflammatory cytokines (e.g. IL-1α, TNF-α and IL-8) (P < 0.05). Such responses could be inhibited by ALA-PDT. P. acnes infection could also significantly increase TLR2 and TLR4 expressions in keratinocytes (P < 0.05), which could be down-regulated by ALA-PDT.ConclusionsALA-PDT could inhibit innate immune responses in keratinocytes treated with P. acnes via TLRs pathways.     

微波联合5-氨基酮戊酸及光动力疗法治疗肛管内尖锐湿疣

目的评价微波联合5-氨基酮戊酸及光动力疗法(ALA-PDT)治疗尖锐湿疣的疗效。方法将86例尖锐湿疣患者分为两组,每组43例。治疗组采用微波、5-氨基酮戊酸与ALA-PDT联合治疗,对照组单用微波治疗。结果治疗组患者痊愈率为83.7%(36/43),复发率为4.7%(2/43);对照组痊愈率为67.4%(29/43),复发率为18.6%(8/43)。两组痊愈率及复发率比较,差异有显著统计学意义(P<0.01)。结论微波联合5-氨基酮戊酸及光动力疗法治疗尖锐湿疣在疗效及复发率方面均明显优于微波治疗。     

Photobleaching-based method to individualize irradiation time during interstitial 5-aminolevulinic acid photodynamic therapy

Interstitial photodynamic therapy (iPDT) is being investigated for the treatment of high-grade human brain malignancies. In recent clinical studies, fluorescence monitoring during iPDT of glioblastoma multiforme has revealed patient-specific accumulation of photosensitizer (aminolevulinic acid (ALA) induced protoporphyrin IX, PpIX) and its photobleaching kinetics. As photosensitizer degradation, also referred to as photobleaching, and tissue damage are caused by the same underlying processes, the photobleaching kinetics might provide a tool for real-time treatment supervision. Here, we show with computer simulations that varying optical properties have a strong influence on the irradiation time required to fully bleach the photosensitizer. We propose a method to potentially determine the time point during iPDT, when the photosensitizer within the target volume has been largely photobleached. Simulations show that it is possible to determine this time point by continuously monitoring the ratio of the fluorescence intensities at two time points during irradiation. We show that this method works for a large range of optical properties, different photobleaching rates and varying inter-fibre distances. In conclusion, the relative fluorescence method offers the potential to individualize irradiation times to consume the photosensitizer within the target tissue during iPDT.     

5-氨基酮戊酸光动力疗法治疗寻常痤疮的临床观察

目的观察5-氨基酮戊酸光动力疗法(ALA-PDT)治疗寻常痤疮的安全性及有效性。方法将90例中重度痤疮患者随机单盲分为两组:治疗组45例,给予ALA-PDT治疗,1次/10 d,共治疗2～4次;对照组45例,口服异维A酸胶囊,每次10 mg,2次/d,共治疗40 d。在治疗的第10、20、30及40天对两组患者进行疗效判断和比较,同时,记录治疗过程中出现的不良反应。结果治疗组患者经过2～4次治疗后,总有效率为97.8%;对照组治疗结束时总有效率为77.8%,治疗组疗效明显优于对照组(P<0.01)。另外,治疗组复发程度明显低于对照组,且病情控制时间明显延长。治疗组的所有皮损,包括粉刺、丘疹、脓疱、囊肿、结节等均比对照组明显减少。结论 ALA-PDT治疗中重度痤疮的疗效明显优于口服异维A酸胶囊,是一种简单、高效、不良反应轻微的治疗中重度寻常痤疮的新方法。     

The effect of hypoxia on photodynamic therapy with 5-aminolevulinic acid in malignant gliomas

BackgroundGlioblastoma (GBM) is a high-grade, poor prognosis tumor that is resistant to standard treatment. The presence of a small number of glioma stem cells (GSCs) surviving in the harsh microenvironment is responsible for their refractoriness. This study aimed to investigate the effect of a hypoxic environment on the sensitivity of GSCs to photodynamic therapy with 5-aminolevulinic acid (ALA-PDT).Materials and methodsSix human GSC lines, Mesenchymal types HGG13, HGG30, HGG1123, and Proneural types HGG146, HGG157, HGG528, were divided into two groups: normoxia (O₂ 21%)-cultured cells (Normoxia-GSCs), and hypoxia (O₂ 5%)-cultured cells (Hypoxia-GSCs). To compare the effects of different oxygen partial pressures on photoporphyrin Ⅸ (PpⅨ) biosynthetic activity, PpⅨ biosynthetic enzyme and transporter expression levels were examined by qRT-PCR; the intracellular PpⅨ concentration was determined using flow cytometry. Additionally, the sensitivity of these two groups of cells to ALA-PDT was evaluated in vitro.ResultsHypoxia-GSCs showed higher mRNA levels of FECH (ferrochelatase), which is required for iron synthesis to convert PpⅨ to heme, compared with Normoxia-GSCs. Flow cytometry revealed that the accumulation of PpⅨ in Hypoxia-GSCs reduced upon incubation with ALA. However, Hypoxia-GSCs showed less reduction in sensitivity to ALA-PDT than Normoxia-GSCs.ConclusionHypoxia-GSCs had lower intracellular PpⅨ accumulation than Normoxia-GSCs due to increased gene expression of FECH, and that their sensitivity to ALA-PDT was reduced less, despite accumulating lower concentrations of PpⅨ. ALA-PDT is a potentially effective therapy for hypoxia-tolerant GSCs that exist in hypoxia at 5% oxygen concentration.     

Therapeutic effects of topical photodynamic therapy with 5-aminolevulinic acid on cervical high-grade squamous intraepithelial lesions

BackgroundTopical photodynamic therapy with 5-aminolevulinic acid (ALA-PDT) is a non-invasive option for treatment of Cervical Intraepithelial Neoplasia (CIN). We investigated the clinical efficacy and safety of ALA-PDT in treatment of patients with cervical high-grade squamous intraepithelial lesion (HSIL) and evaluated the factors that effect the efficacy of PDT.MethodsA total of 99 patients (average age: 30 years (18–45 years old)) with cervical HSIL and high-risk Human Papilloma Virus (hr-HPV) infections and who had received ALA-PDT were enrolled in this retrospective study. Before ALA-PDT, cervical exfoliated cells from all patients were obtained for HPV genotyping, liquid-based cytology test (LBC) and PAX1 methylation (PAX1^m) test. Then, 6 months after ALA-PDT, HPV genotyping, LBC and colposcopy-directed biopsy were conducted. During subsequent follow-up, HPV genotyping and LBC were performed, and colposcopy-directed biopsy was conducted if hr-HPV was positive and/or LBC result was abnormal.ResultsAt 6 months after treatment, total HPV clearance and lesions complete remission (CR) rates were 64.6% (64/99) and 88.9% (88/99), while at 1-year of follow-up, they were 81.3% (65/80) and 92.5% (74/80), respectively. At 1-year follow-up, HPV clearance rate was higher, relative to 6 months after ALA-PDT (p <0.05). At 6 months after treatment, HPV clearance and CR rates in the PAX1 hypermethylation (PAX1^hm) group were 36.8% and 73.7%, which were lower compared to the rates for PAX1 hypomethylation (PAX1^lm) group (71.3%, 92.5%) (p <0.05). Moreover, of the 11 patients with cervical canal lesions, 3 (3/7, 42.9%) patients had cervical canal HSIL persistence and the other 4 cervical canal HSIL and all of the 4 cervical canal LSIL had complete remission.ConclusionsALA-PDT is an effective, safe treatment approach for patients with cervical HSIL and hr-HPV infections. Patients with PAX1^lm showed better therapeutic outcomes than patients with PAX1^hm or cervical canal HSIL.     

Combined treatment with X-ray irradiation and 5-aminolevulinic acid elicits better transcriptomic response of cell cycle-related factors than X-ray irradiation alone

Purpose: 5-Aminolevulinic acid (ALA) is a precursor of the photosensitizer protoporphyrin (PpIX) used in photodynamic therapy. In our previous work, PpIX enhanced the generation of reactive oxygen species by X-ray irradiation. In this study, we evaluated the potential of ALA as an endogenous sensitizer to X-ray irradiation.

Methodology: Tumor-bearing C57BL/6J mice implanted with B16-BL6 melanoma cells were subsequently treated with irradiation (3?Gy/day for 10 days; total, 30?Gy) plus local administration of 50?mg/kg ALA 24?hours prior to each irradiation (ALA-XT). Tumor-bearing mice without treatment (NT), those treated with ALA only (ALAT), and those treated with X-ray irradiation only (XT) were used as controls.

Results: ALA potentiated tumor suppression by X-ray irradiation. In microarray analyses using tumor tissue collected after 10 sessions of fractional irradiation, functional analysis revealed that the majority of dysregulated genes in the XT and ALA-XT groups were related to cell-cycle arrest. Finally, the XT and ALA-XT groups differed in the strength of expression, but not in the pattern of expression.

Conclusions: mRNA analysis revealed that the combined use of ALA and X-ray irradiation sensitized tumors to X-ray treatment. Furthermore, the present results were consistent with ALA’s tumor suppressive effects in vivo.