Are prophylactic antibiotics required for combined intracavitary and interstitial brachytherapy of gynecologic cancers?

The purpose of this study is to evaluate the need for prophylactic antibiotic treatment prior to combined intracavitary and interstitial (hybrid) brachytherapy for gynecologic cancer. A total of 105 gynecologic cancer patients received 405 brachytherapy sessions, including 302 sessions of intracavitary brachytherapy and 103 sessions of hybrid brachytherapy. Prophylactic antibiotics were administered before 35% of the hybrid brachytherapy sessions. The incidence of postbrachytherapy fever and the frequency of subsequent antibiotic use for infection were compared between treatment groups. Among patients treated with hybrid brachytherapy, fever ≥37.5°C occurred in 16.4% of those not receiving prophylactic antibiotics and 16.7% of those receiving prophylactic antibiotics (P > 0.05). Similarly, fever ≥38.0°C occurred in 4.9% of patients not receiving prophylactic antibiotics and 2.4% of those receiving prophylactic antibiotics (P > 0.05). Additional antibiotics were used to treat postbrachytherapy infections in 4.8% of the group receiving prophylactic antibiotics and 0% of those not receiving prophylactic antibiotics, again without statistically significant difference. There were also no significant differences in posttreatment fever incidence and antibiotics use for infection between intracavitary brachytherapy and hybrid brachytherapy sessions. In conclusion, the incidences of infection and fever are low following hybrid brachytherapy, so prophylactic antibiotics are generally unnecessary.

Calreticulin Upregulation in Cervical Cancer Tissues From Patients After 10 Gy Radiation Therapy.

Purpose: Understanding the immune response during radiation therapy (RT) in a clinical setting is imperative for maximizing the efficacy of combined RT and immunotherapy. Calreticulin, a major damage-associated molecular pattern that is exposed on the cell surface after RT, is presumed to be associated with the tumor-specific immune response. Here, we examined changes in calreticulin expression in clinical specimens obtained before and during RT and analyzed its relationship with the density of CD8+ T cells in the same patient set. Methods and Materials: This retrospective analysis evaluated 67 patients with cervical squamous cell carcinoma who were treated with definitive RT. Tumor biopsy specimens were collected before RT and after 10 Gy irradiation. Calreticulin expression in tumor cells was evaluated via immunohistochemical staining. Subsequently, the patients were divided into 2 groups according to the level of calreticulin expression, and the clinical outcomes were compared. Finally, the correlation between calreticulin levels and density of stromal CD8+ T cells was evaluated. Results: The calreticulin expression significantly increased after 10 Gy (82% of patients showed an increase; P < .01). Patients with increased calreticulin levels tended to show better progression-free survival, but this was not statistically significant (P = .09). In patients with high expression of calreticulin, a positive trend was observed between calreticulin and CD8+ T cell density, but the association was not statistically significant (P = .06). Conclusions: Calreticulin expression increased after 10 Gy irradiation in tissue biopsies of patients with cervical cancer. Higher calreticulin expression levels are potentially associated with better progression-free survival and greater T cell positivity, but there was no statistically significant relationship between calreticulin upregulation and clinical outcomes or CD8+ T cell density. Further analysis will be required to clarify mechanisms underlying the immune response to RT and to optimize the RT and immunotherapy combination approach.

Repetitive Painting (REPEAT) Irradiation in Stereotactic Radiotherapy Using Helical Tomotherapy.

BACKGROUND/AIM: Stereotactic radiotherapy (SRT) for spine metastases with helical tomotherapy requires a long irradiation time due to the high dose per fraction. Since helical tomotherapy can neither confirm nor correct the position during irradiation, a plan with a long irradiation time cannot be used in actual clinical practice, given the intra-fractional motion error. To address this problem, we devised a method called REPEAT irradiation. PATIENTS AND METHODS: REPEtitive pAinTing (REPEAT) irradiation is a method of dividing the irradiation for a given fraction per day into several sessions and performing the irradiation after position correction using mega-voltage computed tomography images for each session. In order to evaluate how REPEAT irradiation changes irradiation time and the dose-volume histogram (DVH), a planning study with helical tomotherapy was conducted using CT images of a patient with lumbar spine metastasis. RESULTS: In this case, we found that dividing 3 irradiation fractions into 3 sessions per day (i.e., 9 fractions=9 sessions in 3 days) using REPEAT irradiation shortened the irradiation time per session and simultaneously improved dose-volume histogram parameters. CONCLUSION: Although the optimal number of sessions may differ depending on the patient's condition, the fixing method, the irradiation site, and the calculation parameters, REPEAT irradiation does not require any special equipment and is a simple practical treatment method.

Expression of non-homologous end joining factor, Ku80, is negatively correlated with PD-L1 expression in cancer cells after X-ray irradiation.

The growing importance of antitumour immunity by cancer immunotherapy has prompted studies on radiotherapy-induced immune response. Previous studies have indicated that programmed cell death-1 ligand (PD-L1) expression is regulated by DNA damage signalling. However, PD-L1 up-regulation after radiotherapy has not been fully investigated at the clinical level, particularly in the context of expression of DNA repair factors. The present study examined the correlation of mRNA expression between PD-L1 and non-homologous end joining (NHEJ) factors using The Cancer Genome Atlas database analysis. Among NHEJ factors, Ku80 mRNA expression was negatively correlated with PD-L1 mRNA expression levels in several types of cancer (colon adenocarcinoma, breast invasive carcinoma, skin cutaneous melanoma, lung adenocarcinoma, head and neck squamous cell carcinoma, uterine corpus endometrial carcinoma, cervical squamous cell carcinoma and endocervical adenocarcinoma). To verify the negative correlation in clinical samples, the present study analysed whether Ku80 expression levels affected PD-L1 up-regulation after radiotherapy using cervical squamous cell carcinoma samples. Quantitative evaluation using software analysis of immunohistochemically stained slides revealed that patients with low Ku80 positivity in biopsy specimens demonstrated increased PD-L1 expression levels after 10 Gy irradiation (Spearman's rank correlation coefficient=-0.274; P=0.017). Furthermore, PD-L1 induction levels in tumour cells after 10 Gy of irradiation were significantly inversely correlated with Ku80 expression levels (Spearman's rank correlation coefficient=-0.379; P<0.001). The present study also confirmed that short interfering RNA-mediated Ku80 depletion was associated with greater X-ray-induced PD-L1 up-regulation in HeLa cells. These results indicated that radiotherapy could enhance PD-L1 induction in tumour cells with low Ku80 expression in a clinical setting. Furthermore, these data highlighted Ku80 as a potential predictive biomarker for immune checkpoint therapy combined with radiotherapy.

Local Action of Neprilysin Exacerbates Pressure Overload Induced Cardiac Remodeling.

[Figure: see text].

Analysis of radiotherapy-induced alteration of CD8+ T cells and PD-L1 expression in patients with uterine cervical squamous cell carcinoma.

Radiotherapy induces an immune response in the cancer microenvironment that may influence clinical outcome. The present study aimed to analyse the alteration of CD8+ T-cell infiltration and programmed death-ligand 1 (PD-L1) expression following radiotherapy in clinical samples from patients with uterine cervical squamous cell carcinoma. Additionally, the current study sought to analyse the association between these immune responses and clinical outcomes. A total of 75 patients who received either definitive chemoradiotherapy or radiotherapy were retrospectively analyzed. CD8+ T-cell infiltration and PD-L1 expression were determined by immunohistochemistry using biopsy specimens before radiotherapy (pre-RT) and after 10 Gy radiotherapy (post-10 Gy). The PD-L1+ rate was significantly increased from 5% (4/75) pre-RT to 52% (39/75) post-10 Gy (P<0.01). Despite this increase in the PD-L1+ rate post-10 Gy, there was no significant association between both pre-RT and post-10 Gy and overall survival (OS), locoregional control (LC) and progression-free survival (PFS). On the other hand, the CD8+ T-cell infiltration density was significantly decreased for all patients (median, 23.1% pre-RT vs. 16.9% post-10 Gy; P=0.038); however, this tended to increase in patients treated with radiotherapy alone (median, 17.7% pre-RT vs. 24.0% post-10 Gy; P=0.400). Notably, patients with high CD8+ T-cell infiltration either pre-RT or post-10 Gy exhibited positive associations with OS, LC and PFS. Thus, the present analysis suggested that CD8+ T-cell infiltration may be a prognostic biomarker for patients with cervical cancer receiving radiotherapy. Furthermore, immune checkpoint inhibitors may be effective in patients who have received radiotherapy, since radiotherapy upregulated PD-L1 expression in cervical cancer specimens.

FIGO 2018 Staging for Cervical Cancer: Influence on Stage Distribution and Outcomes in the 3D-Image-Guided Brachytherapy Era.

Recent widespread use of three-dimensional image-guided brachytherapy (3D-IGBT) has improved radiotherapy outcomes of cervical cancer dramatically. In 2018, the International Federation of Gynecology and Obstetrics (FIGO) staging system for cervical cancer was revised. However, the influence of the revisions on the stage distribution and outcomes of cervical cancers treated with 3D-IGBT remains unclear. Here, we retrospectively analyzed 221 patients with cervical squamous cell carcinoma treated with definitive radiotherapy using 3D-IGBT (median follow-up, 60 months). The stage distribution and outcomes were compared between the 2009 and 2018 schemas. Stage migration occurred in 52.9% of the patients. Patients classified with the 2018 criteria as stage IIICr had the highest proportion (43.8%) of migration, and were mainly from the 2009 stages IIB and IIIB. The 2009 and 2018 schemas showed comparable performance at stratifying 5-year overall survival (OS) and 5-year progression-free survival (PFS) for patients in stages IB-IVA. The 2018 criteria effectively stratified 5-year OS and PFS in the stage III substages. The 5-year OS and PFS for stage IIIC1r patients varied according to tumor T stage. These data provide evidence for the utility of the revised 2018 FIGO staging system in the clinical management of cervical cancers in the 3D-IGBT era.

AST-120, an Oral Carbon Absorbent, Protects against the Progression of Atherosclerosis in a Mouse Chronic Renal Failure Model by Preserving sFlt-1 Expression Levels.

Soluble Flt-1 (sFlt-1), an endogenous antagonist of the proatherogenic cytokine placental growth factor, is decreased in chronic kidney disease (CKD), leading to atherosclerotic progression. In this study, we investigated the effect of AST-120, an oral carbon adsorbent which can remove uremic toxins, on sFlt-1 expression levels and atherosclerosis progression. Atherosclerotic apolipoprotein E-deficient mice underwent a 5/6 nephrectomy (5/6 NR) or a sham operation (sham) at 8 weeks of age and were then treated or not with oral AST-120 for 12 weeks. sFlt-1 expression levels and the degree of atherosclerosis were assessed at 22 weeks of age in each of the four groups (sham; n = 7, 5/6 NR; n = 10, sham + AST-120: n = 8, 5/6 NR + AST-120; n = 8). The expression levels of sFlt-1 mRNA in the kidney were significantly lower in the 5/6 NR group than in the sham group, but AST-120 treatment prevented this decrease in sFlt-1 levels. Similarly, the atherosclerotic plaque area of the thoracoabdominal aorta was significantly larger in the 5/6 NR group than in the sham group, and AST-120 treatment prevented this increase in atherosclerosis. AST-120 could, therefore, be used as a therapeutic to treat atherosclerosis in patients with CKD.

FGFR Signaling as a Candidate Therapeutic Target for Cancers Resistant to Carbon Ion Radiotherapy.

Radiotherapy is an essential component of cancer therapy. Carbon ion radiotherapy (CIRT) promises to improve outcomes compared with standard of care in many cancers. Nevertheless, clinicians often observe in-field recurrence after CIRT. This indicates the presence of a subset of cancers that harbor intrinsic resistance to CIRT. Thus, the development of methods to identify and sensitize CIRT-resistant cancers is needed. To address this issue, we analyzed a unique donor-matched pair of clinical specimens: a treatment-naïve tumor, and the tumor that recurred locally after CIRT in the same patient. Exon sequencing of 409 cancer-related genes identified enrichment of somatic mutations in FGFR3 and FGFR4 in the recurrent tumor compared with the treatment-naïve tumor, indicating a pivotal role for FGFR signaling in cancer cell survival through CIRT. Inhibition of FGFR using the clinically available pan-FGFR inhibitor LY2874455 sensitized multiple cancer cell lines to carbon ions at 3 Gy (RBE: relative biological effectiveness), the daily dose prescribed to the patient. The sensitizer enhancement ratio was 1.66 ± 0.17, 1.27 ± 0.09, and 1.20 ± 0.18 in A549, H1299, and H1703 cells, respectively. Our data indicate the potential usefulness of the analytical pipeline employed in this pilot study to identify targetable mutations associated with resistance to CIRT, and of LY21874455 as a sensitizer for CIRT-resistant cancers. The results warrant validation in larger cohorts.

Dosimetric parameters predictive of nasolacrimal duct obstruction after carbon-ion radiotherapy for head and neck carcinoma.

BACKGROUND AND PURPOSE: Little information is available on the risk factors for nasolacrimal duct obstruction after radiotherapy for head and neck tumors. We investigated the incidence and predictive dosimetric parameters for nasolacrimal duct obstruction following carbon-ion radiotherapy for head and neck tumors. MATERIALS AND METHODS: Twenty-eight patients with head and neck non-squamous cell carcinoma were analyzed in this single-institution prospective study. More than half of the tumors were located in the nasal cavity and maxillary sinus. Carbon-ion radiotherapy consisting of 57.6 or 64.0 Gy(relative biological effectiveness; RBE) in 16 fractions was administered. Nasolacrimal duct obstruction was recorded according to Common Terminology Criteria for Adverse Events version 4.0. Cutoff values were determined using receiver operating characteristic (ROC) curve analysis. VX indicates the volume irradiated with X Gy(RBE). RESULTS: The median follow-up period was 60.3 months. Incidences of Grade 1 and 2 nasolacrimal duct obstructions were 46% (13/28) and 7% (2/28), respectively; no Grade 3 or greater toxicities were recorded. Throughout the dose range, the volumes of the irradiated nasolacrimal ducts were significantly higher in the obstruction-positive patients than in the obstruction-negative patients (p < 0.001 for V10, V20, V30, V40, V50, and V60). Cutoff values determined by the ROC curve analysis classified the obstruction-positive patients with an accuracy of >96% over the entire range of V10-V60. CONCLUSION: The incidence and predictive dosimetric parameters for nasolacrimal duct obstruction after carbon-ion radiotherapy were demonstrated in a prospective cohort. These data should help optimize carbon-ion radiotherapy treatments for patients with head and neck tumors.

Suppressed Production of Soluble Fms-Like Tyrosine Kinase-1 Contributes to Myocardial Remodeling and Heart Failure.

Soluble fms-like tyrosine kinase-1 (sFlt-1), an endogenous inhibitor of vascular endothelial growth factor and placental growth factor, is involved in the pathogenesis of cardiovascular disease. However, the significance of sFlt-1 in heart failure has not been fully elucidated. We found that sFlt-1 is decreased in renal failure and serves as a key molecule in atherosclerosis. In this study, we aimed to investigate the role of the decreased sFlt-1 production in heart failure, using sFlt-1 knockout mice. sFlt-1 knockout mice and wild-type mice were subjected to transverse aortic constriction and evaluated after 7 days. The sFlt-1 knockout mice had significantly higher mortality (52% versus 15%; P=0.0002) attributable to heart failure and showed greater cardiac hypertrophy (heart weight to body weight ratio, 8.95±0.45 mg/g in sFlt-1 knockout mice versus 6.60±0.32 mg/g in wild-type mice; P<0.0001) and cardiac dysfunction, which was accompanied by a significant increase in macrophage infiltration and cardiac fibrosis, than wild-type mice after transverse aortic constriction. An anti-placental growth factor-neutralizing antibody prevented pressure overload-induced cardiac hypertrophy, fibrosis, and cardiac dysfunction. Moreover, monocyte chemoattractant protein-1 expression was significantly increased in the hypertrophied hearts of sFlt-1 knockout mice compared with wild-type mice. Monocyte chemoattractant protein-1 inhibition with neutralizing antibody ameliorated maladaptive cardiac remodeling in sFlt-1 knockout mice after transverse aortic constriction. In conclusion, decreased sFlt-1 production plays a key role in the aggravation of cardiac hypertrophy and heart failure through upregulation of monocyte chemoattractant protein-1 expression in pressure-overloaded heart.

Gradual reduction in rRNA transcription triggers p53 acetylation and apoptosis via MYBBP1A.

The nucleolus, whose primary function is ribosome biogenesis, plays an essential role in p53 activation. Ribosome biogenesis is inhibited in response to cellular stress and several nucleolar proteins translocate from the nucleolus to the nucleoplasm, where they activate p53. In this study, we analysed precisely how impaired ribosome biogenesis regulates the activation of p53 by depleting nucleolar factors involved in rRNA transcription or rRNA processing. Nucleolar RNA content decreased when rRNA transcription was inhibited. In parallel with the reduced levels of nucleolar RNA content, the nucleolar protein Myb-binding protein 1 A (MYBBP1A) translocated to the nucleoplasm and increased p53 acetylation. The acetylated p53 enhanced p21 and BAX expression and induced apoptosis. In contrast, when rRNA processing was inhibited, MYBBP1A remained in the nucleolus and nonacetylated p53 accumulated, causing cell cycle arrest at the G1 phase by inducing p21 but not BAX. We propose that the nucleolus functions as a stress sensor to modulate p53 protein levels and its acetylation status, determining cell fate between cell cycle arrest and apoptosis by regulating MYBBP1A translocation.

The nucleolar protein nucleophosmin is essential for autophagy induced by inhibiting Pol I transcription.

Various cellular stresses activate autophagy, which is involved in lysosomal degradation of cytoplasmic materials for maintaining nutrient homeostasis and eliminating harmful components. Here, we show that RNA polymerase I (Pol I) transcription inhibition induces nucleolar disruption and autophagy. Treatment with autophagy inhibitors or siRNA specific for autophagy-related (ATG) proteins inhibited autophagy but not nucleolar disruption induced by Pol I transcription inhibition, which suggested that nucleolar disruption was upstream of autophagy. Furthermore, treatment with siRNA specific for nucleolar protein nucleophosmin (NPM) inhibited this type of autophagy. This showed that NPM was involved in autophagy when the nucleolus was disrupted by Pol I inhibition. In contrast, NPM was not required for canonical autophagy induced by nutrient starvation, as it was not accompanied by nucleolar disruption. Thus, our results revealed that, in addition to canonical autophagy, there may be NPM-dependent autophagy associated with nucleolar disruption.

Perturbation of ribosome biogenesis drives cells into senescence through 5S RNP-mediated p53 activation.

The 5S ribonucleoprotein particle (RNP) complex, consisting of RPL11, RPL5, and 5S rRNA, is implicated in p53 regulation under ribotoxic stress. Here, we show that the 5S RNP contributes to p53 activation and promotes cellular senescence in response to oncogenic or replicative stress. Oncogenic stress accelerates rRNA transcription and replicative stress delays rRNA processing, resulting in RPL11 and RPL5 accumulation in the ribosome-free fraction, where they bind MDM2. Experimental upregulation of rRNA transcription or downregulation of rRNA processing, mimicking the nucleolus under oncogenic or replicative stress, respectively, also induces RPL11-mediated p53 activation and cellular senescence. We demonstrate that exogenous expression of certain rRNA-processing factors rescues the processing defect, attenuates p53 accumulation, and increases replicative lifespan. To summarize, the nucleolar-5S RNP-p53 pathway functions as a senescence inducer in response to oncogenic and replicative stresses.

Novel nucleolar pathway connecting intracellular energy status with p53 activation.

In response to a shortage of intracellular energy, mammalian cells reduce energy consumption and induce cell cycle arrest, both of which contribute to cell survival. Here we report that a novel nucleolar pathway involving the energy-dependent nucleolar silencing complex (eNoSC) and Myb-binding protein 1a (MYBBP1A) is implicated in these processes. Namely, in response to glucose starvation, eNoSC suppresses rRNA transcription, which results in a reduction in nucleolar RNA content. As a consequence, MYBBP1A, which is anchored to the nucleolus via RNA, translocates from the nucleolus to the nucleoplasm. The translocated MYBBP1A induces acetylation and accumulation of p53 by enhancing the interaction between p300 and p53, which eventually leads to the cell cycle arrest (or apoptosis). Taken together, our results indicate that the nucleolus works as a sensor that transduces the intracellular energy status into the cell cycle machinery.

Critical role of the nucleolus in activation of the p53-dependent postmitotic checkpoint.

Cells eventually exit from mitosis during sustained arrest at the spindle checkpoint, without sister chromatid separation and cytokinesis. The resulting tetraploid cells are arrested in the subsequent G1 phase in a p53-dependent manner by the regulatory function of the postmitotic G1 checkpoint. Here we report how the nucleolus plays a critical role in activation of the postmitotic G1 checkpoint. During mitosis, the nucleolus is disrupted and many nucleolar proteins are translocated from the nucleolus into the cytoplasm. Among the nucleolar factors, Myb-binding protein 1a (MYBBP1A) induces the acetylation and accumulation of p53 by enhancing the interaction between p300 and p53 during prolonged mitosis. MYBBP1A-dependent p53 activation is essential for the postmitotic G1 checkpoint. Thus, our results demonstrate a novel nucleolar function that monitors the prolongation of mitosis and converts its signal into activation of the checkpoint machinery.