Non-lethal Conditions Research Articles

Impact of ocean warming on early development of the Mediterranean mussel Mytilus galloprovincialis: Effects on larval susceptibility to potential vibrio pathogens

In a global change scenario, ocean warming and pathogen infection can occur simultaneously in coastal areas, threatening marine species. Data are shown on the impact of temperature on early larvae of the Mediterranean mussel Mytilus galloprovincialis. Increasing temperatures (18-20-22 °C) altered larval phenotypes at 48 hpf and affected gene expression from eggs to 24 and 48 hpf, with shell biogenesis related genes among the most affected. The effects of temperature on larval susceptibility to infection were evaluated using Vibrio coralliilyticus, a coral pathogen increasingly associated with bivalve mortalities, whose ecology is affected by global warming. Malformations and mortalities at 48 hpf were observed at higher temperature and vibrio concentrations, with interactive effects. In non-lethal conditions, interactions on gene expression at 24 and 48 hpf were also detected. Although temperature is the main environmental driver affecting M. galloprovincialis early larvae, warming may increase the susceptibility to vibrio infection, with consequences on mussel populations.

Using birds of prey to manage pest bird flocks under lethal and non-lethal conditions – A review

Abstract Raptors have been successfully used to disperse and often control flocks of pest birds. However, the question that has not been resolved is, “If the raptor kills a small number of the target flock, does this improve the efficiency of control?” This mini-review examines the few research reports that have been published that can shed light on this question.

Targeting FGFR3 signaling and drug repurposing for the treatment of SLC26A2-related chondrodysplasia in mouse model

BackgroundMutations in Slc26a2 cause a spectrum of autosomal-recessive chondrodysplasia with a significant and negligible influence on the quality of life. It has been reported that Slc26a2 deficiency triggers the ATF6 branch of the UPR, which may, in turn, activate the negative regulator of the FGFR3 signaling pathway. However, the correlation between the deletion of Slc26a2 and the augmentation of downstream phosphorylation of FGFR3 has not been investigated in vivo. MethodsFirst, we constructed Slc26a2 and Fgfr3 double knockout mouse lines and observed gross views of the born mice and histological staining of the tibial growth plates. The second approach was to construct tamoxifen-inducible Cre-ERT2 mouse models to replicate SLC26A2-related non-lethal dysplastic conditions. Pharmacological intervention was performed by administering the FGFR3 inhibitor NVP-BGJ398. The effect of NVP-BGJ398 on chondrocytes was assessed by Alcian blue staining, proliferation, apoptosis, and chondrocyte-specific markers and then verified by western blotting for variations in the downstream markers of FGFR3. The growth process was detected using X-rays, micro-CT examination, histomorphometry staining of growth plates, and immunofluorescence. ResultsGenetic ablation of Fgfr3 in embryonic Slc26a2-deficient chondrocytes slightly attenuated chondrodysplasia. Subsequently, in the constructed mild dysplasia model, we found that postnatal intervention with Fgfr3 gene in Slc26a2-deficient chondrocytes partially alleviated chondrodysplasia. In chondrocyte assays, NVP-BGJ398 suppressed the defective phenotype of Slc26a2-deficient chondrocytes and restored the phosphorylation downstream of FGFR3 in a concentration-dependent manner. In addition, in vivo experiments showed significant alleviation of impaired chondrocyte differentiation, and micro-CT analysis showed a clear improvement in trabecular bone microarchitectural parameters. ConclusionOur results suggested that inhibition of FGFR3 signaling pathway overactivation and NVP-BGJ398 has promising therapeutic implications for the development of SLC26A2-related skeletal diseases in humans. The translational potential of this articleOur data provide genetic and pharmacological evidence that targeting FGFR3 signaling via NVP-BGJ398 could be a route for the treatment of SLC26A2-associated skeletal disorders, which promisingly advances translational applications and therapeutic development.

Preimplantation Genetic Testing (PGT) for Non-Lethal Correctable Conditions Through Population Carrier Screening

An increasing number of patients without family history of genetic disease are referred for preimplantation genetic testing of monogenic disorders (PGT-M) after ascertainment through population (expanded) carrier screening (ECS), increasing the proportion of non-lethal correctable genetic conditions in PGT-M indication profile. The aim of this paper is to analyze the current dynamics of these changes in our PGT-M series, which is the world’s largest PGT-M experience. This was analyzed using our PGT-M for two prevalent examples of non-lethal correctable genetic conditions, phenylketonuria (PKU) and hereditary hearing loss (HHL) during the period of 2005-2022. During this period, 91 PGT-M cycles were performed for PKU, involving testing for 108 mutant alleles in PAH gene, and 262 PGT-M cycles for HHL, involving testing for up to 300 mutations in 13 different genes causing hearing loss. PGT-M for these non-lethal correctable conditions resulted in the birth of 54 babies free of PKU and 134 children free of HHL. Dynamics of PGT-M referrals during this period of 17 years demonstrated the shift from retrospective to prospective application of PGT-M for both conditions, with 87% of prospective PGT-M performed for PKU, and 82% for HHL, performed for couples who had no affected relatives with PKU or HHL. These at-risk couples were ascertained through ECS in the last decade, making it possible to provide the option of prospective PGT-M for these non-lethal correctable conditions.

International commission on radiological protection report 152(2022): Radiation detriment calculation methodology

International commission on radiological protection report 152(2022): Radiation detriment calculation methodology

Fast and global reorganization of the chloroplast protein biogenesis network during heat acclimation.

Photosynthesis is a central determinant of plant biomass production, but its homeostasis is increasingly challenged by heat. Little is known about the sensitive regulatory principles involved in heat acclimation that underly the biogenesis and repair of chloroplast-encoded core subunits of photosynthetic complexes. Employing time-resolved ribosome and transcript profiling together with selective ribosome proteomics, we systematically deciphered these processes in chloroplasts of Chlamydomonas reinhardtii. We revealed protein biosynthesis and altered translation elongation as central processes for heat acclimation and showed that these principles are conserved between the alga and the flowering plant Nicotiana tabacum. Short-term heat exposure resulted in specific translational repression of chlorophyll a-containing core antenna proteins of photosystems I and II. Furthermore, translocation of ribosome nascent chain complexes to thylakoid membranes was affected, as reflected by the increased accumulation of stromal cpSRP54-bound ribosomes. The successful recovery of synthesizing these proteins under prolonged acclimation of nonlethal heat conditions was associated with specific changes of the co-translational protein interaction network, including increased ribosome association of chlorophyll biogenesis enzymes and acclimation factors responsible for complex assembly. We hypothesize that co-translational cofactor binding and targeting might be bottlenecks under heat but become optimized upon heat acclimation to sustain correct co-translational protein complex assembly.

Healthcare professionals' attitudes towards termination of pregnancy at viable stage.

Upon prenatal diagnosis of congenital malformations, termination of pregnancy (TOP) may be an option, sometimes at a gestational age when the fetus is already viable (late TOP). We aimed to study attitudes towards late TOP of all tertiary healthcare professionals involved in late TOP practice. A mail survey was conducted among all physicians and paramedical professionals involved in late TOP decision-making in all eight centers with a Neonatal Intensive Care Unit in Flanders, Belgium (N=117). The questionnaire contained general and case-based attitude items. Response rate was 79%. Respondents were either physicians (51.1%) or paramedical professionals (49.9%). The composition of professionals involved in late TOP decision-making was heterogeneous between the eight centers. Late TOP was highly accepted in both lethal fetal conditions (100%) and serious (but not lethal) fetal conditions (95.6%). Where the fetus is healthy, 19.8% of respondents agreed with late TOP for maternal psychological problems and fewer respondents (13.2%) agreed with late TOP in the case of maternal socio-economic problems (P=.002). Physicians more often preferred feticide over neonatal palliative care in the case of non-lethal fetal conditions compared with paramedical professionals (68.1% vs 53.2%, P=.013). Almost nine out of ten respondents (89.1%) agreed that in the event of a serious (non-lethal) neonatal condition, administering drugs with the explicit intention to end neonatal life was acceptable. Behavioral intentions indicate that even in situations with an unclear diagnosis and unpredictable prognosis, 85.6% of professionals would still consider late TOP. Healthcare professionals practicing late TOP in Flanders, Belgium have a high degree of tolerance towards late TOP, irrespective of sociodemographic factors, and are demanding legislative change regarding active life-ending in the fetal and neonatal periods. Further research should explore the correlation of attitudes to late TOP with actual medical decisions taken in daily clinical practice.

Coexistence of plant species under harsh environmental conditions: an evaluation of niche differentiation and stochasticity along salt marsh creeks

BackgroundEcologists have achieved much progress in the study of mechanisms that maintain species coexistence and diversity. In this paper, we reviewed a wide range of past research related to these topics, focusing on five theoretical bodies: (1) coexistence by niche differentiation, (2) coexistence without niche differentiation, (3) coexistence along environmental stress gradients, (4) coexistence under non-equilibrium versus equilibrium conditions, and (5) modern perspectives.ResultsFrom the review, we identified that there are few models that can be generally and confidently applicable to different ecological systems. This problem arises mainly because most theories have not been substantiated by enough empirical research based on field data to test various coexistence hypotheses at different spatial scales. We also found that little is still known about the mechanisms of species coexistence under harsh environmental conditions. This is because most previous models treat disturbance as a key factor shaping community structure, but they do not explicitly deal with stressful systems with non-lethal conditions. We evaluated the mainstream ideas of niche differentiation and stochasticity for the coexistence of plant species across salt marsh creeks in southwestern Denmark. The results showed that diversity indices, such as Shannon–Wiener diversity, richness, and evenness, decreased with increasing surface elevation and increased with increasing niche overlap and niche breadth. The two niche parameters linearly decreased with increasing elevation. These findings imply a substantial influence of an equalizing mechanism that reduces differences in relative fitness among species in the highly stressful environments of the marsh. We propose that species evenness increases under very harsh conditions if the associated stress is not lethal. Finally, we present a conceptual model of patterns related to the level of environmental stress and niche characteristics along a microhabitat gradient (i.e., surface elevation).ConclusionsThe ecology of stressful systems with non-lethal conditions will be increasingly important as ongoing global-scale climate change extends the period of chronic stresses that are not necessarily fatal to inhabiting plants. We recommend that more ecologists continue this line of research.

Transplants for non-lethal conditions: a case against hand transplantation in minors

Human allografts for life-threatening organ failure have been demonstrated to be lifesaving and are now considered to be standard of care for many conditions. Transplantation of non-vital anatomic body parts...

Attitudes of paediatric and obstetric specialists towards prenatal surgery for lethal and non-lethal conditions

BackgroundWhile prenatal surgery historically was performed exclusively for lethal conditions, today intrauterine surgery is also performed to decrease postnatal disabilities for non-lethal conditions. We sought to describe physicians' attitudes about...

Increased nuchal translucency in fetuses with a normal karyotype-diagnosis and management: An observational study.

The use of nuchal translucency (NT) in 1992 by Nicolaides et al was a major breakthrough in screening for chromosomal aneuploidies at the end of the first trimester. However, pathological conditions other than chromosomal aneuploidies are also associated with increased NT, which can also be detected in normal fetuses. This study sought to evaluate the causes of this ultrasound sign in a group of patients from Iasi, Romania.During the decade-long study period, there were 71 certified cases involving increased NT; the patients in these cases underwent diagnostic amniocentesis and karyotyping.In most of the examined cases (55 cases, 78%), there was no aneuploidy. The remaining cases involved trisomy 21 (T21) (18%), trisomy 18 (T18) (2%), or triploidy (2%). In most cases, the indication for amniocentesis was increased NT alone (81%), whereas the remaining cases also involved advanced maternal age (5.5%), abnormal serologic markers (10%), or other ultrasound signs (3.5%) (2 cases—cardiac anomalies and fetal hydrops). A favorable pregnancy outcome at term was achieved in 40 cases (56% from total, 72% from euploid pregnancies); kidney anomalies or nonlethal cardiac conditions were observed in 12 cases (17%), 6 of which involved complications associated with premature onset of labor, and miscarriages occurred in 6 cases. Three cases were lost at follow-up.Although it is common practice to assume that increased NT is an indication for amniocentesis, both literature results and our study findings indicate that the majority of cases with increased NT involve no aneuploidy and result in a favorable outcome if no other anomaly is present. Better evidence-based management of such cases could be promoted by conducting larger, multicenter studies, and following cases for longer periods.

Desempeño del Phaseolus vulgaris bajo riego parcial cultivado en un sistema de respuesta hidrogravitrópica

In the experimental area of the UNALM (Lima-Peru) was evaluated on partial root-zone drying irrigation treatments (RPR300 and RPR500, ml) and full irrigation (RC300 and RC500, ml control), the impact of xylem potential (Yx) and stomatal conductance (gs) in common bean plants ( Phaseolus vulgaris L.) cultivated in systems (pots) of hydrogravitropic response. A randomized complete block design with 12 plants/pots per treatments was used in three replicates. To control the irrigation application and manage to maintain the Yx nonlethal conditions (<-15 bars), a water-soil retention curve was generated. The values of gs before irrigation (between 217.18 and 268.67 mm m -2 s -1 ) showed that only RPR500 plants were maintained under optimal water conditions, despite low levels of Yx (between -9.92 and -7.33 bar); situation that could be attributed to the ability of the roots to balance those moments when half of these structures were inside soil with low humidity, while the opposite half was favorable soil water level.

Attitudes Towards Prenatal Genetic Counseling, Prenatal Genetic Testing, and Termination of Pregnancy among Southeast and East Asian Women in the United States.

Recognizing the heterogeneity of the Asian population with regards to acculturation, education, health awareness, and cultural values is vital for tailoring culturally sensitive and appropriate care. Prior studies show that cultural values influence perceptions of genetics within Asian populations. The reputation of the family unit factors into decisions such as pregnancy termination and disclosure of family medical history, and the nondirective model of American genetic counseling may conflict with the historical Asian model of paternalistic health care. Previous studies also provide conflicting evidence regarding correlations between education, acculturation, age, and awareness and perceptions of genetic testing. The aims of this study were to describe attitudes towards prenatal genetics among Southeast and East Asian women living in the United States for varying amounts of time and to explore sociocultural factors influencing those attitudes. Twenty-three Asian women who were members of Asian cultural organizations in the United States were interviewed via telephone about their attitudes towards prenatal genetic counseling, prenatal genetic testing, and termination of pregnancy. Responses were transcribed and coded for common themes using a thematic analysis approach. Four major themes emerged. In general, participants: (1) had diverse expectations for genetic counselors; (2) tended to weigh risks and benefits with regards to genetic testing decisions; (3) had mixed views on termination for lethal and non-lethal genetic conditions; and (4) identified cultural factors which influenced testing and termination such as lack of available resources, societal shame and stigma, and family pressure. These findings may allow prenatal genetic counselors to gain a richer, more nuanced understanding of their Asian patients and to offer culturally tailored prenatal genetic counseling.

Exploring the Pharmacokinetic Profile of Remifentanil in Mid-Trimester Gestations Undergoing Fetal Intervention Procedures.

Background: Indications for surgery during pregnancy have increased. Specifically fetal interventions have increased from conditions that were considered lethal like twin-twin transfusion syndrome and severe fetal anemia to non-lethal conditions like myelomeningocele. The optimal anesthetic agent for in utero surgery is yet to be determined. Success of the procedure is often dictated by the efficacy of the anesthetic to immobilize the fetus without over-sedating mom. Remifentanil is used as preferred agent due to its short half-life however pharmacokinetics in pregnancy is unknown.Objective: To determine the pharmacokinetic parameters of remifentanil in a mid-trimester pregnant patient population undergoing fetal intervention.Study Design: A validated liquid chromatography assay with ultraviolet absorbance was employed to estimate maternal serum remifentanil levels. Blood samples were obtained at baseline and at selected time points: 5, 15, 30, 45, 60 min after the beginning of the remifentanil infusion and at 15, 30, and 60 min post end of infusion.Results: Ten pregnant patients were enrolled in the study however only eight patients had sampling obtained at all time points. The mean gestational age was 22.2 (±2.7) weeks, maternal age was 27.8 (±5.1) years and body mass index was 29.6 (±6.3). After receiving a continuous infusion of remifentanil, mean total dose was 975.3 μg, Cmin was 2.0 ng/mL and Cmax was 8.4 ng/mL. A two-compartment model best described the plasma remifentanil data. Mean pharmacokinetic parameters were: volume of distribution (Vdc) = 124.6 L (16.2–530.8 L), maternal remifentanil total clearance (Clt) = 170.7 L/h (17.7–486.9 L/h), and half-life (t½) = 0.6 h (0.2–0.9 h). The maternal remifentanil area under the curve (AUC) ranged from 2.7 to 21.7 μg/L*h. The mean alpha-acidic glycoprotein was 124.8 mg/dL (81.3–149.8).Conclusion: The pharmacokinetic profile of remifentanil in pregnant women is similar to previously reported general population profiles. This data did provide potential rationale for the clinical observations why when remifentanil is dosed based on non-pregnant guidelines, it did not uniformly provide adequate fetal immobilization as per anecdotal perception of operating fetal surgeons. These findings are important for the development of further clinical studies to optimize dosing for surgery during pregnancy including the estimation of placental transfer and total fetal exposure.

Leaf Growth Response to Mild Drought: Natural Variation in Arabidopsis Sheds Light on Trait Architecture.

Plant growth and crop yield are negatively affected by a reduction in water availability. However, a clear understanding of how growth is regulated under nonlethal drought conditions is lacking. Recent advances in genomics, phenomics, and transcriptomics allow in-depth analysis of natural variation. In this study, we conducted a detailed screening of leaf growth responses to mild drought in a worldwide collection of Arabidopsis thaliana accessions. The genetic architecture of the growth responses upon mild drought was investigated by subjecting the different leaf growth phenotypes to genome-wide association mapping and by characterizing the transcriptome of young developing leaves. Although no major effect locus was found to be associated with growth in mild drought, the transcriptome analysis delivered further insight into the natural variation of transcriptional responses to mild drought in a specific tissue. Coexpression analysis indicated the presence of gene clusters that co-vary over different genetic backgrounds, among others a cluster of genes with important regulatory functions in the growth response to osmotic stress. It was found that the occurrence of a mild drought stress response in leaves can be inferred with high accuracy across accessions based on the expression profile of 283 genes. A genome-wide association study on the expression data revealed that trans regulation seems to be more important than cis regulation in the transcriptional response to environmental perturbations.

Single-Genotype Syntrophy by Rhodopseudomonas palustris Is Not a Strategy to Aid Redox Balance during Anaerobic Degradation of Lignin Monomers.

Rhodopseudomonas palustris has emerged as a model microbe for the anaerobic metabolism of p-coumarate, which is an aromatic compound and a primary component of lignin. However, under anaerobic conditions, R. palustris must actively eliminate excess reducing equivalents through a number of known strategies (e.g., CO2 fixation, H2 evolution) to avoid lethal redox imbalance. Others had hypothesized that to ease the burden of this redox imbalance, a clonal population of R. palustris could functionally differentiate into a pseudo-consortium. Within this pseudo-consortium, one sub-population would perform the aromatic moiety degradation into acetate, while the other sub-population would oxidize acetate, resulting in a single-genotype syntrophy through acetate sharing. Here, the objective was to test this hypothesis by utilizing microbial electrochemistry as a research tool with the extracellular-electron-transferring bacterium Geobacter sulfurreducens as a reporter strain replacing the hypothesized acetate-oxidizing sub-population. We used a 2 × 4 experimental design with pure cultures of R. palustris in serum bottles and co-cultures of R. palustris and G. sulfurreducens in bioelectrochemical systems. This experimental design included growth medium with and without bicarbonate to induce non-lethal and lethal redox imbalance conditions, respectively, in R. palustris. Finally, the design also included a mutant strain (NifA*) of R. palustris, which constitutively produces H2, to serve both as a positive control for metabolite secretion (H2) to G. sulfurreducens, and as a non-lethal redox control for without bicarbonate conditions. Our results demonstrate that acetate sharing between different sub-populations of R. palustris does not occur while degrading p-coumarate under either non-lethal or lethal redox imbalance conditions. This work highlights the strength of microbial electrochemistry as a tool for studying microbial syntrophy.

Induction of Perivascular Neural Stem Cells and Possible Contribution to Neurogenesis Following Transient Brain Ischemia/Reperfusion Injury.

Recent therapeutic advances have increased the likelihood of recanalizing the obstructed brain arteries in patients with stroke. Therefore, it is important to understand the fate of neural cells under transient ischemia/reperfusion injury. Accumulating evidence shows that neurogenesis occurs in perivascular regions following brain injury, although the precise mechanism and origin of these newborn neurons under transient ischemia/reperfusion injury remain unclear. Using a mouse model of transient brain ischemia/reperfusion injury, we found that neural stem cells (NSCs) develop within injured areas. This induction of NSCs following ischemia/reperfusion injury was observed even in response to nonlethal ischemia, although massive numbers of NSCs were induced by lethal ischemia. Immunohistochemical and immunoelectron microscopic studies indicated that platelet-derived growth factor receptor beta-positive (PDGFRβ+) pericytes within injured areas following nonlethal ischemia began to express the NSC marker nestin as early as 3days after transient ischemia/reperfusion. Some PDGFRβ+ pericytes expressed the immature neuronal marker doublecortin at day 7. These findings indicate that brain pericytes are a potential source of the perivascular NSCs that generate neuronal cells under lethal and nonlethal ischemic conditions following transient ischemia/reperfusion. Thus, brain pericytes might be a target for neurogenesis mediation in patients with nonlethal and lethal ischemia following transient ischemia/reperfusion injury.

Gene Transfer Strategies to Promote Chondrogenesis and Cartilage Regeneration.

Gene transfer has been used experimentally to promote chondrogenesis and cartilage regeneration. While it is controversial to apply gene therapy for nonlethal conditions such as cartilage defect, there is a possibility that the transfer of therapeutic transgenes may dramatically increase the effectiveness of cell therapy and reduce the quantity of cells that are needed to regenerate cartilage. Single or combination of growth factors and transcription factors has been transferred to mesenchymal stem cells or articular chondrocytes using both nonviral and viral approaches. The current challenge for the clinical applications of genetically modified cells is ensuring the safety of gene therapy while guaranteeing effectiveness. Viral gene delivery methods have been mainstays currently with enhanced safety features being recently refined. On the other hand, efficiency has been greatly improved in nonviral delivery. This review summarizes the history and recent update on the gene transfer to enhance chondrogenesis from stem cells or articular chondrocytes.

Development of a stress-induced mutagenesis module for autonomous adaptive evolution of Escherichia coli to improve its stress tolerance.

BackgroundMicrobial tolerance to different environmental stresses is of importance for efficient production of biofuels and biochemical. Such traits are often improved by evolutionary engineering approaches including mutagen-induced mutagenesis and successive passage. In contrast to these approaches which generate mutations in rapidly growing cells, recent research showed that mutations could be generated in non-dividing cells under stressful but non-lethal conditions, leading to the birth of the theory of stress-induced mutagenesis (SIM). A molecular mechanism of SIM has been elucidated to be mutagenic repair of DNA breaks. This inspired us to develop a synthetic SIM module to simulate the mutagenic cellular response so as to accelerate microbial adaptive evolution for an improved stress tolerance.ResultsA controllable SIM evolution module was devised based on a genetic toggle switch in Escherichia coli. The synthetic module enables expression and repression of the genes related to up- and down-regulation responses during SIM in a bistable way. Upon addition of different inducers, the module can be turned on or off, triggering transition to a mutagenic or a high-fidelity state and thus allowing periodic adaptive evolution. Six genes (recA, dinB, umuD, ropS, ropE, and nusA) in the up-regulation responses were evaluated for their potentials to enhance the SIM rate. Expression of recA, dinB, or ropS alone increased the SIM rate by 4.5- to 13.7-fold, whereas their combined expression improved the rate by 31.9-fold. Besides, deletion of mutL increased the SIM rate by 82-fold. Assembly of these genes into the SIM module in the mutL-deletion E. coli strain elevated the SIM rate by nearly 3000-fold. Accelerated adaptive evolution of E. coli equipped with this synthetic SIM module was demonstrated under n-butanol stress, with the minimal inhibitory concentration of n-butanol increasing by 56 % within 2.5 months.ConclusionsA synthetic SIM module was constructed to simulate cellular mutagenic responses during SIM. Based on this, a novel evolutionary engineering approach—SIM-based adaptive evolution—was developed to improve the n-butanol tolerance of E. coli.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-015-0276-1) contains supplementary material, which is available to authorized users.

Transcriptome Analysis of Porphyrin-Accumulated and X-Ray-Irradiated Cell Cultures under Limited Proliferation and Non-Lethal Conditions.

5-Aminolevulinic acid (ALA) is a precursor of the photosensitizer used in photodynamic therapy. It accumulates in tumor cells and subsequently metabolizes to protoporphyrin IX (PpIX), which generates singlet oxygen after light irradiation. PpIX enhances the generation of reactive oxygen species following physicochemical interactions with X-rays. ALA-based treatment using fractionated doses of irradiation suppressed tumor growth in a mouse melanoma model. To study the transcriptomic effects of PpIX, microarray analyses were conducted using HeLa cells with limited proliferation capacity. Based on the p-values (p < 0.01), we selected genes showing altered expression in each treatment group with reference to the non-treatment (NT) group. We detected 290, 196 and 28 upregulated genes, as well as 203, 146 and 36 downregulated genes after a 6 h-long PpIX treatment (1 μg/mL) prior to 3 Gy X-ray irradiation (PpIX-XT), 3 Gy X-ray irradiation alone (XT) and PpIX treatment alone (PpIXT), respectively. Functional analysis revealed that a majority of the regulated genes in the XT and PpIX-XT groups were related to cell-cycle arrest. The XT and PpIX-XT groups differed in the quantity, but not in the quality of their gene expression. The combined effect of PpIX and X-ray irradiation sensitized HeLa cells to X-ray treatment.