High N6-methyladenosine-activated TCEAL8 mRNA is a novel pancreatic cancer marker.

N6-methyladenosine (m6A) is an RNA modification involved in RNA processing and widely found in transcripts. In cancer cells, m6A is upregulated, contributing to their malignant transformation. In this study, we analyzed gene expression and m6A modification in cancer tissues, ducts, and acinar cells derived from pancreatic cancer patients using MeRIP-seq. We found that dozens of RNAs highly modified by m6A were detected in cancer tissues compared with ducts and acinar cells. Among them, the m6A-activated mRNA TCEAL8 was observed, for the first time, as a potential marker gene in pancreatic cancer. Spatially resolved transcriptomic analysis showed that TCEAL8 was highly expressed in specific cells, and activation of cancer-related signaling pathways was observed relative to TCEAL8-negative cells. Furthermore, among TCEAL8-positive cells, the cells expressing the m6A-modifying enzyme gene METTL3 showed co-activation of Notch and mTOR signaling, also known to be involved in cancer metastasis. Overall, these results suggest that m6A-activated TCEAL8 is a novel marker gene involved in the malignant transformation of pancreatic cancer.

Revealing neuropilin expression patterns in pancreatic cancer: From single­cell to therapeutic opportunities (Review).

Pancreatic cancer, one of the most fatal types of human cancers, includes several non-epithelial and stromal components, such as activated fibroblasts, vascular cells, neural cells and immune cells, that are involved in different cancers. Vascular endothelial cell growth factor 165 receptors 1 [neuropilin-1 (NRP-1)] and 2 (NRP-2) play a role in the biological behaviors of pancreatic cancer and may appear as potential therapeutic targets. The NRP family of proteins serve as co-receptors for vascular endothelial growth factor, transforming growth factor ß, hepatocyte growth factor, fibroblast growth factor, semaphorin 3, epidermal growth factor, insulin-like growth factor and platelet-derived growth factor. Investigations of mechanisms that involve the NRP family of proteins may help develop novel approaches for overcoming therapy resistance in pancreatic cancer. The present review aimed to provide an in-depth exploration of the multifaceted roles of the NRP family of proteins in pancreatic cancer, including recent findings from single-cell analysis conducted within the context of pancreatic adenocarcinoma, which revealed the intricate involvement of NRP proteins at the cellular level. Through these efforts, the present study endeavored to further reveal their relationships with different biological processes and their potential as therapeutic targets in various treatment modalities, offering novel perspectives and directions for the treatment of pancreatic cancer.

Circulating Plasma Exosomal PD-L1 Predicts Prognosis of Head and Neck Squamous Cell Carcinoma After Radiation Therapy.

Purpose: Radiation therapy is widely used to treat head and neck squamous cell carcinoma (HNSCC). This study evaluated the association between circulating plasma programmed death-ligand 1 (PD-L1) and the outcomes of patients with HNSCC after radiation therapy. Methods and Materials: In this retrospective observational study, plasma samples of 76 patients with HNSCC who underwent radiation therapy from June 2019 to August 2021 were analyzed. These plasma samples were obtained before radiation therapy. The median follow-up was 32.5 months. Total and exosomal PD-L1 was measured by enzyme-linked immunosorbent assay and retrospectively analyzed for association with overall survival (OS), progression-free survival (PFS), and local control (LC). Prognostic factors among patients' characteristics and circulating PD-L1 in plasma were evaluated by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses. Results: The median concentration of total PD-L1 in plasma was 115.1 pg/mL (95% CI, 114.7-137.9 pg/mL), and the median concentration of exosomal PD-L1 was 2.8 pg/mL (95% CI, 6.0-13.0 pg/mL). Univariate and multivariate analyses showed exosomal PD-L1 as a prognostic factor for PFS and LC. Patients with high exosomal PD-L1 in plasma had poor PFS and LC compared with those with low exosomal PD-L1, indicating that 1-year PFS was 79.2% versus 33.3% (P < .001) and 1-year LC was 87.3% versus 50.0% (P < .001) in patients with high and low exosomal PD-L1, respectively. However, exosomal PD-L1 in plasma had no significant effect on OS. Total PD-L1 in plasma did not correlate with PFS, LC, and OS. Conclusions: The pretreatment circulating exosomal PD-L1 in plasma of patients with HNSCC was a prognostic factor after radiation therapy.

RNA methylation in inflammatory bowel disease.

RNA modifications, including the renowned m6A, have recently garnered significant attention. This chemical alteration, present in mRNA, exerts a profound influence on protein expression levels by affecting splicing, nuclear export, stability, translation, and other critical processes. Although the role of RNA methylation in the pathogenesis and progression of IBD and colorectal cancer has been reported, many aspects remain unresolved. In this comprehensive review, we present recent studies on RNA methylation in IBD and colorectal cancer, with a particular focus on m6A and its regulators. We highlight the pivotal role of m6A in the pathogenesis of IBD and colorectal cancer and explore the potential applications of m6A modifications in the diagnosis and treatment of these diseases.

Irradiated Cell-derived Exosomes Enhance Cell Proliferation and Radioresistance via the MAPK/Erk Pathway.

BACKGROUND/AIM: Radiation therapy is pivotal in cancer treatment; however, its efficacy is limited by challenges such as tumor recurrence. This study delves into the role of exosomes, which are molecular cargo-bearing vesicles, in influencing cell proliferation, radioresistance, and consequent post-irradiation tumor recurrence. Given the significance of exosomes from irradiated malignancies in diagnostics and therapy, it is vital to delineate their functional dynamics, especially in breast and cervical cancer cell lines, where the impact of irradiation on exosome behavior remains enigmatic. MATERIALS AND METHODS: Using MDA-MB-231 and HeLa cell lines, exosomes were isolated from the culture supernatant via ultracentrifugation. The bicinchoninic acid assay was used to measure exosome quantities in irradiated and non-irradiated cells. Radiosensitivity was assessed using colony formation assays, while the role of the MAPK/Erk signaling pathway in recipient cell proliferation and radioresistance was probed using western blotting. RESULTS: Irradiated cells, in both MDA-MB-231 and HeLa lines, produced significantly more exosomes than their non-irradiated counterparts. Co-culturing irradiated cells with exosomes led to increased cell survival post-irradiation and enhanced cell proliferation in both cell lines. Western blotting indicated elevated p-Erk expression in such cells, underscoring the influence of the MAPK/Erk pathway in radioresistance and proliferation. CONCLUSION: The study establishes a potential nexus between exosome secretion and tumor resurgence following radiotherapy. The spotlight falls on the MAPK/ERK signaling conduit as a key influencer. This new knowledge provides an innovative strategy for counteracting cancer recurrence after radiotherapy, emphasizing the importance of understanding the multifaceted roles of exosomes in this context.

Stereotactic ablative body radiotherapy with a central high dose using CyberKnife for metastatic lung tumors.

BACKGROUND: The CyberKnife system features a robotically-positioned linear accelerator to deliver real-time image-guided stereotactic ablative body radiotherapy (SABR). It achieves steep dose gradients using irradiation from hundreds of different directions and increases the central dose of the gross tumor volume (GTV) without increasing the marginal dose to the planning target volume. We evaluated the effectiveness and safety of SABR with a central high dose using CyberKnife for metastatic lung tumors. METHODS: A total of 73 patients with 112 metastatic lung tumors treated with CyberKnife were retrospectively analyzed. Local control, progression-free survival, and overall survival were calculated using the Kaplan-Meier method. The median age was 69.2 years. The most common primary sites were the uterus (n = 34), colorectum (n = 24), head and neck (n = 17), and esophagus (n = 16). For peripheral lung tumors, the median radiation dose was 52 Gy in 4 fractions, whereas for centrally located lung tumors, it was 60 Gy in 8-10 fractions. The dose prescription was defined as 99% of the solid tumor components of the GTV. The median maximum dose within the GTV was 61.0 Gy. The GTV and planning target volume were enclosed conformally by the 80% and 70% isodose lines of the maximum dose, respectively. The median follow-up period was extended to 24.7 months; it was 33.0 months for survivors. RESULTS: The 2-year local control, progression-free survival, and overall survival rates were 89.1%, 37.1%, and 71.3%, respectively. Toxicities of grade ≥ 2 were noted as grade 2 and 3 radiation pneumonitis in one patient each. The two patients with grade 2 or higher radiation pneumonitis had both received simultaneous irradiation at two or three metastatic lung tumor sites. No toxicity of grade ≥ 2 was observed in patients with metastasis in one lung only. CONCLUSIONS: SABR with a central high dose using CyberKnife for metastatic lung tumors is effective with acceptable toxicity. TRIAL REGISTRATION: Number: 20557, Name: Stereotactic ablative radiotherapy using CyberKnife for metastatic lung tumor, URL: http://www.radonc.med.osaka-u.ac.jp/pdf/SBRT.pdf , Date of registration: April 1, 2021 (retrospectively registered), Date of enrollment: May 1, 2014.

Emerging roles of long noncoding and circular RNAs in pancreatic ductal adenocarcinoma.

An international project on the human genome revealed that various RNAs (e.g., messenger RNAs, microRNAs, and long noncoding RNAs [lncRNAs] and their subclass circular RNA [circRNA)) are involved in the pathogenesis of different human diseases, including cancer. Recent studies have highlighted the critical roles of lncRNAs and circRNA in pancreatic ductal adenocarcinoma (PDAC), especially in the epithelial-mesenchymal transition, a phenomenon regulating cancer metastasis. Growing research in this field has indicated that the tertiary structure of lncRNAs supposedly regulates biological function via RNA-RNA or RNA-protein associations, aiding early diagnosis and therapy selection for various diseases, including cancer. Here we describe the emerging roles of ncRNAs in PDAC and highlight how these ncRNAs can be used to detect and control this intractable cancer.

COVID-19 vaccine-induced Recurrence of the Radiation Recall Phenomenon in the Laryngeal Mucosa Due to a VEGF Inhibitor.

Purpose: The radiation recall phenomenon (RRP) is a rare and unexpected late complication of radiation therapy (RT). Although predominantly in the skin, RRP of the upper respiratory tract has also been reported. In general, RRP is caused by anticancer agents, and the COVID-19 vaccine has also been reported to cause RRP in recent years. Methods and Materials: A 50-year-old woman who had received RT around the larynx 3 years prior and was receiving a docetaxel + ramucirumab (RAM) regimen experienced recurrent sore throat. The administration of RAM was discontinued after a gastroscopic examination revealed mucosal bleeding from around the larynx, which was thought to be RRP caused by RAM, a vascular endothelial growth factor inhibitor. Results: After the remission of the RRP, the patient received a COVID-19 vaccine (Pfizer-BioNTech). Five days later, the appearance of cough and recurrence of sore throat worsened with time, and marked stridor was observed. The patient was admitted, and steroid pulse therapy was administered for 3 days starting on day 18 after vaccination. On day 50 after vaccination, edema of the vocal cords improved. Conclusions: When administering COVID-19 vaccines, considering that these vaccines may cause RRP is important, because RRP can be fatal in patients with a history of RT in the laryngeal region and treated with vascular endothelial growth factor inhibitors.

Establishment of a reference single-cell RNA sequencing dataset for human pancreatic adenocarcinoma.

Single-cell RNA sequencing (scRNAseq) has been used to assess the intra-tumor heterogeneity and microenvironment of pancreatic ductal adenocarcinoma (PDAC). However, previous knowledge is not fully universalized. Here, we built a single cell atlas of PDAC from six datasets containing over 70 samples and >130,000 cells, and demonstrated its application to the reanalysis of the previous bulk transcriptomic cohorts and inferring cell-cell communications. The cell decomposition of bulk transcriptomics using scRNAseq data showed the cellular heterogeneity of PDAC; moreover, high levels of tumor cells and fibroblasts were indicative of poor-prognosis. Refined tumor subtypes signature indicated the tumor cell dynamics in intra-tumor and their specific regulatory network. We further identified functionally distinct tumor clusters that had close interaction with fibroblast subtypes via different signaling pathways dependent on subtypes. Our analysis provided a reference dataset for PDAC and showed its utility in research on the microenvironment of intra-tumor heterogeneity.

Radiation therapy enhances systemic antitumor efficacy in PD-L1 therapy regardless of sequence of radiation in murine osteosarcoma.

Recent studies demonstrate that immune checkpoint blockade (ICB) increases the chances of the abscopal effect, an anti-tumor effect outside the radiation field in radiation therapy. However, the optimal sequence between radiation and ICB remains unclear. To investigate the impact of sequence of radiation in anti-PD-L1 antibody (P1) therapy on immune microenvironments and antitumor efficacies in local and abscopal tumors, metastatic LM8 osteosarcoma cells were inoculated into both legs of C3H mice. For irradiation, only one side leg was irradiated at 10 Gy. Then mice were divided into four groups: administrated anti-PD-L1 antibody three times (P1 monotherapy), receiving radiation 3 days prior to P1 therapy (P1+pre-Rad), and receiving concurrent radiation with P1 therapy (P1+conc-Rad). Thereafter, tumor immune microenvironment and tumor volume changes were analyzed in irradiated and unirradiated tumors. The P1+pre-Rad regimen increased the proportion of CD8+ programmed cell death 1 (PD-1)+ granzyme B (GzmB)+ reinvigorated T cells and decreased the proportion of CD8+ PD-1+ GzmB- exhausted T cells than P1+conc-Rad regimen in unirradiated tumors. Combination regimens suppressed tumor growth in irradiated tumors compared with that in P1 monotherapy. In both irradiated and unirradiated tumors, significant tumor growth suppression and prolonged overall survival were observed under both combination treatment regimens compared with P1 monotherapy. However, no distinct differences in unirradiated tumor volume and survival were observed between P1+pre-Rad and P1+conc-Rad groups. These results suggest that local irradiation is necessary to improve systemic treatment efficacy in P1 therapy regardless of sequence of local irradiation.

N(6)-methyladenosine methylation-regulated polo-like kinase 1 cell cycle homeostasis as a potential target of radiotherapy in pancreatic adenocarcinoma.

In pancreatic cancer, methyltransferase-like 3 (METTL3), a N(6)-methyladenosine (m6A) methyltransferase, has a favorable effect on tumors and is a risk factor for patients' prognosis. However, the details of what genes are regulated by METTL3 remain unknown. Several RNAs are methylated, and what genes are favored in pancreatic cancer remains unclear. By epitranscriptomic analysis, we report that polo-like kinase 1 (PLK1) is an important hub gene defining patient prognosis in pancreatic cancer and that RNA methylation is involved in regulating its cell cycle-specific expression. We found that insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) binds to m6A of PLK1 3' untranslated region and is involved in upregulating PLK1 expression and that demethylation of this site activates the ataxia telangiectasia and Rad3-related protein pathway by replicating stress and increasing mitotic catastrophe, resulting in increased radiosensitivity. This suggests that PLK1 methylation is essential for cell cycle maintenance in pancreatic cancer and is a new therapeutic target.

High Dose Local Photon Irradiation Is Crucial in Anti-CTLA-4 Antibody Therapy to Enhance the Abscopal Response in a Murine Pancreatic Carcinoma Model.

Pancreatic cancer is an extremely treatment-resistant neoplasm to chemotherapy and immunotherapy. The combination of photon beam irradiation and anti-CTLA-4 antibody (C4) for the anti-tumor effect enhancement at local and distant tumors (abscopal tumors) was investigated using the pancreatic ductal adenocarcinoma (PDAC) mouse model. Pan02 cells were bilaterally inoculated to both legs of C57BL/6 mice. High dose photon beams in a hypofractionation or a single fraction were delivered to the tumors on one leg. Monotherapy with C4 via i.p. was not effective for PDAC. The high dose irradiation to the local tumors produced significant shrinkage of irradiated tumors but did not induce the abscopal responses. In contrast, the combination therapy of high dose photon beam irradiation in both hypofractionation and a single fraction with C4 enhanced the anti-tumor effect for abscopal tumors with significantly prolonged overall survival. The flow cytometric analysis revealed that the combination therapy dramatically decreased the regulatory T cell (Treg) proportion while increasing the cytotoxic T lymphocytes in both local and abscopal tumors. These results suggest that high dose photon beam irradiation plays an important role in C4 therapy to enhance the abscopal response with immune microenvironment changes in PDAC, regardless of the fractionation in radiation therapy.

Stereotactic Ablative Radiotherapy Using CyberKnife for Stage I Non-small-cell Lung Cancer: A Retrospective Analysis.

BACKGROUND/AIM: We evaluated the effectiveness and safety of stereotactic ablative radiotherapy (SABR) delivered using Cyberknife in patients with stage I non-small-cell lung cancer. PATIENTS AND METHODS: The clinical results of 153 patients with 161 lung cancers treated with CyberKnife between May 2014 and August 2020 at the Osaka University Hospital were retrospectively analyzed. The median age was 80 years (range=48-99 years). Nine patients (5.6%) had interstitial pneumonia. The median radiation dose was 52 Gy (range=40-70 Gy) in 4-10 fractions, and the median follow-up extended to 21.4 months (range=0-68.9 months). RESULTS: The 2-year local control, progression-free, and overall survival rates were 91.9%, 61.7%, and 84.8%, respectively. Toxicities of grade ≥3 were observed in 13 (8.1%) patients; one patient with interstitial pneumonia developed grade 5 radiation pneumonitis and one patient developed grade 5 bronchopulmonary hemorrhage. CONCLUSION: In patients with stage I non-small-cell lung cancer, SABR using Cyberknife was effective with acceptable toxicity.

Poly (ADP-ribose) polymerase inhibitors sensitize cancer cells to hypofractionated radiotherapy through altered selection of DNA double-strand break repair pathways.

PURPOSE: Poly (ADP-ribose) polymerase inhibitors (PARPi) are known to induce radiosensitization. However, the exact mechanisms of radiosensitization remain unclear. We previously reported that PARPi may have a unique radiosensitizing effect to enhance ß-components of the linear-quadratic model. The aim of this study was to evaluate PARPi in combination with high-dose-per-fraction radiotherapy and to elucidate the underlying mechanisms of its radiosensitization. MATERIALS AND METHODS: Radiosensitizing effects of PARPi PJ34, olaparib, and veliparib were measured using a colony-forming assay in the human cancer cell lines, HCT116, NCI-H460, and HT29. Six different radiation dose fractionation schedules were examined by tumor regrowth assay using three-dimensional multicellular spheroids of HCT116, NCI-H460, SW620, and HCT15. The mechanisms of radiosensitization were analyzed by measuring DNA double-strand breaks (DSB), DNA damage responses, chromosomal translocations, cellular senescence, and cell cycle analysis. RESULTS: Olaparib and PJ34 were found to show radiosensitization preferentially at higher radiation doses per fraction. Similar results were obtained using a mouse model bearing human tumor xenografts. A kinetic analysis of DNA damage responses and repairs showed that olaparib and PJ34 reduced the homologous recombination activity. However, a neutral comet assay showed that PJ34 treatment did not affect the physical rejoining of DNA-DSBs induced by ionizing radiation. Cell cycle analysis revealed that olaparib and PJ34 strikingly increased G1 tetraploid cells following irradiation, leading to premature senescence. The C-banding analysis of metaphase spreads showed that olaparib and PJ34 significantly increased ionizing radiation-induced dicentric chromosomes. The data suggests that PARPi olaparib and PJ34 altered the choice of DNA-DSB repair pathways rather than reducing the total amount of DNA-DSB repair, which resulted in increased repair errors. Increased quadratic misrepair was one of the mechanisms of PARP-mediated radiosensitization, preferentially at the higher dose range compared to the lower dose range. CONCLUSION: PARPi may be a promising candidate to combine with stereotactic hypofractionated radiotherapy, aiming at high-dose region-directed radiosensitization.

Methylosystem for Cancer Sieging Strategy.

As cancer is a genetic disease, methylation defines a biologically malignant phenotype of cancer in the association of one-carbon metabolism-dependent S-adenosylmethionine (SAM) as a methyl donor in each cell. Methylated substances are involved in intracellular metabolism, but via intercellular communication, some of these can also be secreted to affect other substances. Although metabolic analysis at the single-cell level remains challenging, studying the "methylosystem" (i.e., the intercellular and intracellular communications of upstream regulatory factors and/or downstream effectors that affect the epigenetic mechanism involving the transfer of a methyl group from SAM onto the specific positions of nucleotides or other metabolites in the tumor microenvironment) and tracking these metabolic products are important research tasks for understanding spatial heterogeneity. Here, we discuss and highlight the involvement of RNA and nicotinamide, recently emerged targets, in SAM-producing one-carbon metabolism in cancer cells, cancer-associated fibroblasts, and immune cells. Their significance and implications will contribute to the discovery of efficient methods for the diagnosis of and therapeutic approaches to human cancer.

Monitoring expiratory carbon monoxide to study the effect of complete smoking cessation on definitive radiation therapy for early stage glottic carcinoma.

BACKGROUND: Previous studies reported that cigarette smoking during radiation therapy was associated with unfavorable outcomes in various cancers using medical interviewing or monitoring of cotinine. Here, we evaluated the effect of smoking cessation on definitive radiation therapy for early stage glottic carcinoma by monitoring expiratory carbon monoxide (CO). MATERIAL AND METHODS: We enrolled 103 patients with early glottic carcinoma (T1N0/T2N0 = 79/24) who underwent conventional radiotherapy between 2005 and 2016. The median age was 70 years. Pathologically, all patients had squamous cell carcinoma. Since 2009, we confirmed smoking cessation before radiation therapy by medical interviews. Since 2014, we measured expiratory CO to strictly monitor smoking cessation. The patients were divided according to diagnosis years: 'no cessation' (2005-2008), 'incomplete cessation' (2009-2013), and 'complete cessation' (2014-2016). We retrospectively analyzed the local recurrence rate and disease-free survival (DFS). RESULTS: The median follow-up period was 60.1 months (range, 1.9-110.0 months). The 2-year local recurrence rate in the 'complete cessation' group was 5.3% and tended to be lower than that in the 'incomplete cessation' group (13.7%) and 'no cessation' group (21.2%). Multivariate analysis revealed that 'no cessation' was a risk factor for DFS (hazard ratio [HR] = 4.25) and local recurrence rate (HR = 16.5, p < .05) compared to 'complete cessation.' DISCUSSION: We confirmed that the 'complete cessation' group had better prognosis than the 'no cessation' group by monitoring expiratory CO during radiation therapy for early stage glottic carcinoma. Moreover, monitoring expiratory CO was easier and more suitable than conventional methods for evaluating smoking cessation because it provided real-time measurements.

Dihydroouabain, a novel radiosensitizer for cervical cancer identified by automated high-throughput screening.

BACKGROUND AND PURPOSE: Radiotherapy plays a crucial role in the treatment of cervical cancer, but existing radiosensitizers have limited efficacy in clinical applications. The aims of this study were to establish and verify an efficient method for identifying new radiosensitizers, to use this to identify candidate radiosensitizers for cervical cancer, and to investigate the specific mechanisms of these when used in combination with radiotherapy. MATERIALS AND METHODS: An automated platform for identifying radiosensitizers for cervical cancer was created based on high-throughput screening technology. The radiosensitizing effects of candidate compounds from the LOPAC1280 chemical library were evaluated in radiosensitive and radioresistant cervical cancer cells using a clonogenic survival assay, with cell cycle analyses, and western blot analyses performed for both cell lines. RESULTS: The automated high-throughput screening approach identified four hit compounds. One of the most potent candidates was dihydroouabain (DHO), an inhibitor of Na+/K+-ATPase that has not previously been classified as a radiosensitizer. DHO significantly enhanced radiosensitivity in cervical cancer cells. It also abrogated radiation-induced S phase arrest in cervical cancer cells. Combination treatment significantly caused the inhibition of Chk1 and increased DNA double-strand breaks (DSB). CONCLUSIONS: DHO is a novel radiosensitizer for the treatment of cervical cancer. The automated high-throughput screening platform developed in this study proved to be powerful and effective, with the potential to be widely used in the future identification of radiosensitizers.

Ro 90-7501 Is a Novel Radiosensitizer for Cervical Cancer Cells that Inhibits ATM Phosphorylation.

BACKGROUND/AIM: Ro 90-7501 has been reported as an inhibitor of the amyloid ß42 fibril assembly that is associated with Alzheimer's disease. The present study aimed to elucidate the radiosensitizing effects of Ro 90-7501 and focused on ATM signaling after irradiation. MATERIALS AND METHODS: Clonogenic survival, apoptosis, and cell-cycle assays as well as western blotting were performed in HeLa cells treated with irradiation and Ro 90-7501. Tumor growth delay assay was also performed using BALB/c-nu mice. RESULTS: The combination of irradiation with Ro 90-7501 showed significant radiosensitizing effects in clonogenic survival and tumor growth delay assays. Ro 90-7501 significantly increased apoptosis and impaired cell cycle after irradiation. Western blotting showed that Ro 90-7501 suppressed the phosphorylation of ATM and its downstream proteins, such as H2AX, Chk1, and Chk2, after irradiation. CONCLUSION: Ro 90-7501 inhibits DNA damage response by inhibiting ATM and has significant radiosensitizing effects on cervical cancer cells.

Epigenetic repression of miR-375 is the dominant mechanism for constitutive activation of the PDPK1/RPS6KA3 signalling axis in multiple myeloma.

Cytogenetic/molecular heterogeneity is the hallmark of multiple myeloma (MM). However, we recently showed that the serine/threonine kinase PDPK1 and its substrate RPS6KA3 (also termed RSK2) are universally active in MM, and play pivotal roles in myeloma pathophysiology. In this study, we assessed involvement of aberrant miR-375 repression in PDPK1 overexpression in MM. An analysis of plasma cells from 30 pre-malignant monoclonal gammopathies of undetermined significance and 73 MM patients showed a significant decrease in miR-375 expression in patient-derived plasma cells regardless of the clinical stage, compared to normal plasma cells. Introduction of miR-375 reduced PDPK1 expression in human myeloma cell lines (HMCLs), indicating that miR-375 is the dominant regulator of PDPK1 expression. In addition, miR-375 introduction also downregulated IGF1R and JAK2 in HMCLs. CpG islands in the MIR375 promoter were pathologically hypermethylated in all 8 HMCLs examined and in most of 58 patient-derived myeloma cells. Treatment with SGI-110, a hypomethylating agent, and/or trichostatin A, a histone deacetylase inhibitor, increased miR-375 expression, but repressed PDPK1, IGF1R and JAK2 in HMCLs. Collectively, these results show the universal involvement of overlapping epigenetic dysregulation for abnormal miR-375 repression in MM, which is likely to contribute to myelomagenesis and to subsequent myeloma progression by activating oncogenic signalling pathways.

Detection of chromosomal abnormalities by G-banding and prognostic impact in follicular lymphoma in the rituximab era.

Disease-specific cytogenetic abnormalities involving BCL2 gene rearrangement frequently co-exist with other cytogenetic abnormalities, contributing to disease progression in follicular lymphoma (FL). In the present study, we retrospectively investigated the prognostic impact of BCL2-unrelated cytogenetic abnormalities in FL. Of 139 consecutively diagnosed patients with FL at two independent institutes, metaphase spreads of tumor cells were obtained for use in G-banding analysis in 77 patients. The recurrent additional cytogenetic abnormalities included chromosome gains +5 (n = 8), +7 (n = 16), +12 (n = 10), and +X (n = 12), and losses -8 (n = 7), -13 (n = 12) -15 (n = 7), and 6q- (n = 7). While -15 was associated with shorter progression-free survival (PFS) in all 77 analyzed patients with evaluable G-banding results (p = 0.04), this negative impact was not evident in 42 patients treated using an R-CHOP-like regimen as first-line treatment. By contrast, 6q- was predictive for shorter PFS in patients who were initially treated with R-CHOP-like regimens without maintenance therapy (p < 0.01), while this negative impact was not evident in all 77 patients with evaluable G-banding results. These results suggest the presence of a molecular region in chromosome 6q that is responsible for the shorter PFS following R-CHOP-like chemotherapy.