Radiotherapy-induced miR-223 prevents relapse of breast cancer by targeting the EGF pathway

Blood circulating miRNAs as pancreatic cancer biomarkers: An evidence from pooled analysis and bioinformatics study

Pancreatic cancer (PC) is one of the deadliest cancers, characterized by a poor prognosis. Currently, there are no screening programs for the early detection of PC, and existing diagnostic methods are primarily limited to high-risk individuals. Biomarkers such as CA19-9 have not significantly improved early diagnosis, making the identification of new potential biomarkers crucial for routine clinical practice. Among the candidate biomarkers, miRNAs have been most extensively studied due to their role in regulating gene expression (either as oncomiRs or tumor suppressor miRNAs) and their potential for minimally invasive analysis through liquid biopsy techniques. This review aims to summarize the current literature on blood-circulating miRNAs and their diagnostic value in PC detection, considering the context of CA19-9 and benign pancreatic diseases. The data from the collected studies were curated through both statistical and bioinformatics analyses to identify the most promising miRNAs with optimal diagnostic accuracy for PC detection and to assess their role in the molecular processes leading to tumor development.

Effects of ionizing radiations of different qualities and delivery types on blood cells

This review explores the effects of ionizing radiation on blood and its components, focusing on its applications, biological impacts, and implications for medical and occupational settings. Ionizing radiation is a cornerstone of modern medicine, playing a critical role in diagnostic imaging, cancer treatment, and preventive measures, such as the irradiation of blood units to prevent transfusion-associated graft-versus-host disease. However, it also induces significant alterations in blood cells, including genetic damage, immune suppression, and changes in hematological, biochemical, and hemorheological parameters, depending on the dose, dose rate, and type of radiation. Conventional radiotherapy, hadron therapy, and the emerging FLASH modality exhibit distinct effects on blood. Hadron therapy and FLASH radiotherapy could reduce oxidative stress preserving red blood cell deformability more effectively than conventional methods, thereby minimizing systemic toxicity. However, the underlying mechanisms remain a topic of ongoing investigation. Additionally, studies reveal how different types of radiation, including gamma rays, X-rays, electron beams, and hadrons, uniquely influence blood cells, underscoring the complexity of radiobiological interactions. Challenges and controversies, such as the long-term hematological impact of radiation exposure, individual variability in response, and the potential of radioprotective strategies and immune system stimulation are also addressed. Insights into hemorheological changes and the development of personalized approaches are critical for optimizing therapeutic outcomes and safety protocols. By synthesizing current knowledge, this review emphasizes the need for further research on the effects of ionizing radiation on blood to bridge gaps in understanding and enhance clinical and practical applications.

Role of Non-coding RNAs on the Radiotherapy Sensitivity and Resistance in Cancer Cells

Radiotherapy (RT) is an integral part of treatment management in cancer patients. However, one of the limitations of this treatment method is the resistance of cancer cells to radiotherapy. These restrictions necessitate the introduction of modalities for the radiosensitization of cancer cells. It has been shown that Noncoding RNAs (ncRNAs), along with modifiers, can act as radiosensitivity and radioresistant regulators in a variety of cancers by affecting double strand break (DSB), wnt signaling, glycolysis, irradiation induced apoptosis, ferroptosis and cell autophagy. This review will provide an overview of the latest research on the roles and regulatory mechanisms of ncRNA after RT in in vitro and preclinical researches.

Landscape of the Peripheral Immune Response Induced by Intraoperative Radiotherapy Combined with Surgery in Early Breast Cancer Patients

A comprehensive analysis of the immune response triggered by intraoperative radiation therapy (IORT) remains incomplete. In this study, single-cell RNA sequencing and single-cell T cell receptor sequencing are conducted on peripheral blood mononuclear cells (PBMCs) from patient with early-stage breast cancer before and after IORT. Following IORT combined with surgery (defined as IORT+Surgery), PBMC counts remained stable, with increased proportions of T cells, mononuclear phagocytes, and plasma cells, and a reduction in neutrophil proportions. The cytotoxic score of CD8Teff_GZMK cells increased significantly post-IORT. Communication between CD8Teff_GZMK cells and other immune cells via MIF_CD74 and MIF_TNFRSF14 is decreased after IORT. cDCs showed an upregulation of the MCH II signaling pathway, while memory B cells exhibited enhanced activation of the B cell pathway. T cell clones expanded significantly after treatment. IORT+Surgery demonstrated the ability to partially suppress the anti-tumor effects of neutrophils. Flow cytometry analysis and co-culture experiments are utilized to delve deeper into the functional alterations in T cells. IORT+Surgery significantly enhanced T cell cytotoxic activity. Blockade of PD-1 of post-IORT PBMCs shows higher T-cell activity than that of pre-IORT PBMCs. This research highlights IORT's impact on immune cells, offering insights for targeting immune responses in breast cancer.

Breast Cancer Adjuvant Radiotherapy and Chemotherapy Sequencing: Sequential, Concomitant, or What Else? A Comprehensive Review of the Adjuvant Combinations Journey

Background: To date, in breast cancer (BC) treatment, adjuvant chemotherapy (A-CT) has preceded adjuvant radiotherapy (A-RT). In the last twenty years, the adjuvant treatment of BC has quickly evolved due to better knowledge of its molecular biology, genetic profile, and α/β ratio of 3/4 Gy for tumor and normal tissue radiosensitivity. Thus, new schedules with hypofractionated radiotherapy have been tested, and a third generation of A-CT has been introduced, raising the question of whether it is time to rethink the sequencing between these two approaches. Methods: In the last 20 years, many attempts have been made worldwide to optimize the best sequencing strategy between these two approaches in terms of sequential CT-RT and RT-CT and concomitant and sandwich modalities using drugs and schedules. This paper presents a comprehensive review of the state of the art, analyzing all the available studies to assess the sequencing between A-CT and A-RT with different generations of chemotherapy schedules. Results: More than 8000 patients from 30 studies treated with adjuvant chemotherapy and whole breast radiotherapy who were enrolled in randomized, retrospective, and prospective studies were analyzed. Sequential, concomitant, and sandwich modalities of chemotherapy with conventional or hypofractionated RT schedules from the most important studies were included. The most used sequence was adjuvant chemotherapy followed by conventional or hypofractionated radiotherapy. In the concomitant approach, i.v. CMF has been the most important adopted schedule, while the concomitant use of anthracyclines and taxanes with conventional or hypofractionated radiotherapy has been found to be more toxic. One study analyzed the benefit in terms of reducing adjuvant treatment time with upfront hypofractionated radiotherapy and third-generation chemotherapy. Conclusions: At present, the best sequencing strategy has not yet been defined. This comprehensive review is a journey among the most important randomized, retrospective, and prospective studies that highlights the past, current, and novel time sequencing proposals between A-CT and A-RT to assess the state of the art and provide useful information for future adjuvant approaches in breast cancer treatment.

Comparative long-term oncological outcomes of intraoperative radiotherapy vs. whole-breast irradiation in early breast cancer: a single institute study

Background

Intraoperative radiation therapy (IORT) and whole breast irradiation (WBI) are both effective adjuvant radiotherapy methods for ductal carcinoma in situ (DCIS) or early-stage breast cancer (BC) patients undergoing breast-conserving surgery (BCS). We aim to evaluate the long-term oncological efficacy and refine patient selection criteria based on our findings.

Methods

Female patients who underwent either IORT or WBI from January 2016 to December 2019, with a minimum follow-up of 12 months were collected. IORT was administered as a single fraction of 20 Gray (Gy) to the lumpectomy cavity using the Axxent electronic brachytherapy system, while WBI consisted of a standard fractionation of 50 Gy in 25 fractions, along with a reduced boost of 10 Gy. The clinicopathologic characteristics and oncological outcomes were retrospectively analyzed.

Results

A total of 247 patients were enrolled, comprising 164 with BC and 83 with DCIS. Among them, 112 underwent IORT, and 135 received WBI after BCS. The median age was 62.2 years, with median tumor sizes of 1.5 cm for BC and 1.2 cm for DCIS. At a median follow-up of 64.6 months, IORT demonstrated 11 locoregional recurrences (LRR), 1 metastasis, and 1 death, compared to 4 LRR, 5 metastases, and 2 deaths in the WBI group. WBI yielded significantly higher locoregional control (97.0% vs. 90.2%, p = 0.033), although metastasis-free (96.3% vs. 99.1%, p = 0.166) and overall survival rates (98.4% vs. 99%, p = 0.688) did not differ. The LRR rate was significantly higher in the IORT group among the DCIS or BC patients (p = 0.043). The hazard ratio for locoregional recurrence significantly increased in estrogen-receptor-negative (ER-) patients in both univariate analysis (HR = 4.98, 95% CI = 1.76-14.09, p = 0.002) and multivariate analysis (HR = 40.88, 95% CI = 1.29-1297.84, p = 0.035). Additionally, IORT was associated with increased LRR in the multivariate analysis (HR = 4.71, 95% CI = 1.16-19.06, p = 0.030).

Conclusion

At a long-term follow-up, the LRR rate was higher in the BCS followed by IORT, without significant differences in metastasis-free or overall survival rates. Our data confirmed the importance of exclusion ER- patients for IORT.

MiR-223-3p in Cancer Development and Cancer Drug Resistance: Same Coin, Different Faces

MicroRNAs (miRNAs) are mighty post-transcriptional regulators in cell physiology and pathophysiology. In this review, we focus on the role of miR-223-3p (henceforth miR-223) in various cancer types. MiR-223 has established roles in hematopoiesis, inflammation, and most cancers, where it can act as either an oncogenic or oncosuppressive miRNA, depending on specific molecular landscapes. MiR-223 has also been linked to either the sensitivity or resistance of cancer cells to treatments in a context-dependent way. Through this detailed review, we highlight that for some cancers (i.e., breast, non-small cell lung carcinoma, and glioblastoma), the oncosuppressive role of miR-223 is consistently reported in the literature, while for others (i.e., colorectal, ovarian, and pancreatic cancers, and acute lymphocytic leukemia), an oncogenic role prevails. In prostate cancer and other hematological malignancies, although an oncosuppressive role is frequently described, there is less of a consensus. Intriguingly, NLRP3 and FBXW7 are consistently identified as miR-223 targets when the miRNA acts as an oncosuppressor or an oncogene, respectively, in different cancers. Our review also describes that miR-223 was increased in biological fluids or their extracellular vesicles in most of the cancers analyzed, as compared to healthy or lower-risk conditions, confirming the potential application of this miRNA as a diagnostic and prognostic biomarker in the clinic.

Intraoperative radiotherapy in breast cancer: Alterations to the tumor microenvironment and subsequent biological outcomes (Review)

Intraoperative radiotherapy (IORT) is a precise, single high‑dose irradiation directly targeting the tumor bed during surgery. In comparison with traditional external beam RT, it minimizes damage to other normal tissues, ensures an adequate dose to the tumor bed and results in improved cosmetic outcomes and quality of life. Furthermore, IORT offers a shorter treatment duration, lower economic costs and therapeutic efficacy comparable with traditional RT. However, its relatively higher local recurrence rate limits its further clinical applications. Identifying effective radiosensitizing drugs and rational RT protocols will improve its advantages. Furthermore, IORT may not only damage DNA to directly kill breast tumor cells but also alter the tumor microenvironment (TME) to exert a sustained antitumor effect. Specific doses of IORT may exert anti‑angiogenic effects, and consequently antitumor effects, by impacting post‑radiation peripheral blood levels of vascular endothelial growth factor and delta‑like 4. IORT may also modify the postoperative wound fluid composition to continuously inhibit tumor growth, e.g. by reducing components such as microRNA (miR)‑21, miR‑221, miR‑115, oncostatin M, TNF‑β, IL‑6 and IL‑8, and by elevating levels of components such as miR‑223, to inhibit the ability of postoperative wound fluid to induce proliferation, invasion and migration of residual cancer cells. IORT can also modify cancer cell glucose metabolism to inhibit the proliferation of residual tumor cells. In addition, IORT can induce a bystander effect, eliminating the postoperative wound fluid‑induced epithelial‑mesenchymal transition and tumor stem cell phenotype. Insights gained at the molecular level may provide new directions for identifying novel therapeutic targets and approaches. A more comprehensive understanding of the effects of IORT on the breast cancer (BC) TME may further its clinical application. Hence, the present article reviews the primary effects of IORT on BC and its impact on the TME, aiming to offer fresh research perspectives for relevant professionals.

Higher immunoexpression of CK14 from the Wnt-1/β-catenin pathway in the development of odontomas

Tooth development depends on a series of reciprocal signaling interactions between the oral epithelium and ectomesenchyme. This study aimed to investigate the role of CK14, a protein involved in Wnt-1/β-catenin signaling, in odontogenesis and the development of odontomas. This cross-sectional, retrospective, immunohistochemical study analyzed 30 compound odontomas, 30 complex odontomas, and 17 tooth germs. Higher immunoexpression of CK14 was observed in odontogenic epithelial cells of tooth germs (p < 0.001) and odontogenic epithelial cells of odontomas (p < 0.001). There was higher immunoexpression of Wnt-1 and β-catenin proteins in epithelial cells of tooth germs (p = 0.002 and p < 0.001, respectively), as well as in the ectomesenchyme of odontomas (p = 0.003 and p < 0.001, respectively). β-Catenin was moderately and significantly correlated with CK14 in the membrane of reduced enamel epithelial cells in odontomas (p = 0.007). Higher immunoexpression of CK14 was observed in the odontogenic epithelium during the bud and cap stages and lower immunoexpression in the internal enamel epithelium during the bell stage. In odontomas, lower expression of Wnt-1/β-catenin and higher immunoexpression of CK14 were found in odontogenic epithelial cells, especially adjacent to the mineralized material resembling the tooth formed in these lesions.

Increased Expression of miR-223-3p and miR-375-3p and Anti-Inflammatory Activity in HDL of Newly Diagnosed Women in Advanced Stages of Breast Cancer

The expression of inflammation-related miRs bound to high-density lipoproteins (HDLs), the anti-inflammatory activity of HDLs isolated from individuals with breast cancer, and controls were determined. Forty newly diagnosed women with breast cancer naïve of treatment and 10 control participants were included. Cholesterol-loaded bone-marrow-derived macrophages were incubated with HDL from both groups and challenged with lipopolysaccharide (LPS). Interleukin 6 (IL6) and tumor necrosis factor (TNF) in the medium were quantified. The miRs in HDLs were determined by RT-qPCR. Age, body mass index, menopausal status, plasma lipids, and HDL composition were similar between groups. The ability of HDL to inhibit IL6 and TNF production was higher in breast cancer compared to controls, especially in advanced stages of the disease. The miR-223-3p and 375-3p were higher in the HDLs of breast cancer independent of the histological type of the tumor and had a high discriminatory power between breast cancer and controls. The miR-375-3p was greater in the advanced stages of the disease and was inversely correlated with the secretion of inflammatory cytokines. Inflammation-related miRs and the anti-inflammatory role of HDLs may have a significant impact on breast cancer pathophysiology.

Comparison of intraoperative radiotherapy as a boost vs. simultaneously integrated boosts after breast-conserving therapy for breast cancer

Background

Currently, there are no data from randomized trials on the use of intraoperative radiotherapy (IORT) as a tumor bed boost in women at high risk of local recurrence. The aim of this retrospective analysis was to compare the toxicity and oncological outcome of IORT or simultaneous integrated boost (SIB) with conventional external beam radiotherapy (WBI) after breast conserving surgery (BCS).

Methods

Between 2009 and 2019, patients were treated with a single dose of 20 Gy IORT with 50 kV photons, followed by WBI 50 Gy in 25 or 40.05 in 15 fractions or WBI 50 Gy with SIB up to 58.80-61.60 Gy in 25-28 fractions. Toxicity was compared after propensity score matching. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method.

Results

A 1:1 propensity-score matching resulted in an IORT + WBI and SIB + WBI cohort of 60 patients, respectively. The median follow-up for IORT + WBI was 43.5 vs. 32 months in the SIB + WBI cohort. Most women had a pT1c tumor: IORT group 33 (55%) vs. 31 (51.7%) SIB group (p = 0.972). The luminal-B immunophenotype was most frequently diagnosed in the IORT group 43 (71.6%) vs. 35 (58.3%) in the SIB group (p = 0.283). The most reported acute adverse event in both groups was radiodermatitis. In the IORT cohort, radiodermatitis was grade 1: 23 (38.3%), grade 2: 26 (43.3%), and grade 3: 6 (10%) vs. SIB cohort grade 1: 3 (5.1%), grade 2: 21 (35%), and grade 3: 7 (11.6%) without a meaningful difference (p = 0.309). Fatigue occurred more frequently in the IORT group (grade 1: 21.7% vs. 6.7%; p = 0.041). In addition, intramammary lymphedema grade 1 occurred significantly more often in the IORT group (11.7% vs. 1.7%; p = 0.026). Both groups showed comparable late toxicity. The 3- and 5-year local control (LC) rates were each 98% in the SIB group vs. 98% and 93% in the IORT group (LS: log rank p = 0.717).

Conclusion

Tumor bed boost using IORT and SIB techniques after BCS shows excellent local control and comparable late toxicity, while IORT application exhibits a moderate increase in acute toxicity. These data should be validated by the expected publication of the prospective randomized TARGIT-B study.

Facing the CDK4/6i resistance dilemma in patients with breast cancer, exploration of the resistance mechanism and possible reverse strategy: A narrative review

Breast cancer is one of the highest rates of malignancy of women, approximate 70% metastatic breast cancer are hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-). Hormone therapy is the primary strategy of HR+/HER2- metastatic breast cancer. With the permission of cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i), progress free survival and overall survival were significantly licensed. However, inevitable outcome of CDK4/6i resistance has become the main reason that restricts the clinical benefit of patients. In recent years, the research on dealing with drug resistance has become a hot topic, a large number of molecular mechanisms have been focused, and a lot of experiments have been carried out at the preclinical level. This review summarizes the current knowledge of CDK4/6i resistance mechanism, systematically expounds the signaling pathways and targets leading to CDK4/6i resistance, analyzes different ways and mechanisms, and provides theoretical guidance for the clinical reversal of endocrine therapy resistance.

Biological and clinical review of IORT-induced wound fluid in breast cancer patients

Intraoperative radiotherapy (IORT) has become a growing therapy for early-stage breast cancer (BC). Some studies claim that wound fluid (seroma), a common consequence of surgical excision in the tumor cavity, can reflect the effects of IORT on cancer inhibition. However, further research by our team and other researchers, such as analysis of seroma composition, affected cell lines, and primary tissues in two-dimensional (2D) and three-dimensional (3D) culture systems, clarified that seroma could not address the questions about IORT effectiveness in the surgical site. In this review, we mention the factors involved in tumor recurrence, direct or indirect effects of IORT on BC, and all the studies associated with BC seroma to attain more information about the impact of IORT-induced seroma to make a better decision to remove or remain after surgery and IORT. Finally, we suggest that seroma studies cannot decipher the mechanisms underlying the effectiveness of IORT in BC patients. The question of whether IORT-seroma has a beneficial effect can only be answered in a trial with a clinical endpoint, which is not even ongoing.

The impact of intraoperative radiotherapy on breast cancer: focus on the levels of angiogenic factors

OBJECTIVE

Angiogenesis is one of the hallmarks of cancers that is involved in tumor progression. Angiogenic factors induce the formation of new blood vessels and tumor extension, and finally reduce the survival of patients. Intraoperative radiotherapy (IORT), in which radiation is delivered to the tumor bed can kill cells and change tumor microenvironment. Here, we compared the impact of IORT on the levels of angiogenic factors in the blood and surgical wound fluids (SWF) of the breast cancer patients.

PATIENTS AND METHODS

Three hundred sixty patients, who had undergone breast-conserving surgery between 2013 and 2018, were enrolled in IORT and non-IORT groups non-randomly. Blood and drained wound fluid (WF) samples were collected from the patients before and after surgery, followed by quantification of the amounts of TGF-β, EGF, FGF, VEGF, and DLL4 in the patients using ELISA.

RESULTS

Our results were indicative of significant differences between the pre-surgery and post-surgery serum levels of EGF, DLL4, and VEGF. Furthermore, ROC analyses showed that TGF-β and DLL4 can differentiate of the early-stage from late-stage of the disease. Interestingly, the rate of the death and recurrence was reduced in IORT group.

CONCLUSIONS

In summary, IORT is a safe and effective treatment that can affect angiogenic factors and improve the overall- and recurrence-free survival of breast cancer patients.

CDK4/6 Inhibitors in Combination Therapies: Better in Company Than Alone: A Mini Review

The cyclin D-CDK4/6 complexes play a pivotal role in controlling the cell cycle. Deregulation in cyclin D-CDK4/6 pathway has been described in many types of cancer and it invariably leads to uncontrolled cell proliferation. Many efforts have been made to develop a target therapy able to inhibit CDK4/6 activity. To date, three selective CDK4/6 small inhibitors have been introduced in the clinic for the treatment of hormone positive advanced breast cancer patients, following the impressive results obtained in phase III clinical trials. However, since their approval, clinical evidences have demonstrated that about 30% of breast cancer is intrinsically resistant to CDK4/6 inhibitors and that prolonged treatment eventually leads to acquired resistance in many patients. So, on one hand, clinical and preclinical studies fully support to go beyond breast cancer and expand the use of CDK4/6 inhibitors in other tumor types; on the other hand, the question of primary and secondary resistance has to be taken into account, since it is now very clear that neoplastic cells rapidly develop adaptive strategies under treatment, eventually resulting in disease progression. Resistance mechanisms so far discovered involve both cell-cycle and non-cell-cycle related escape strategies. Full understanding is yet to be achieved but many different pathways that, if targeted, may lead to reversion of the resistant phenotype, have been already elucidated. Here, we aim to summarize the knowledge in this field, focusing on predictive biomarkers, to recognize intrinsically resistant tumors, and therapeutic strategies, to overcome acquired resistance.

Radiobiological effects of wound fluid on breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic culture

Intraoperative radiotherapy (IORT) could abrogate cancer recurrences, but the underlying mechanisms are unclear. To clarify the effects of IORT-induced wound fluid on tumor progression, we treated breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic cell culture systems, respectively. The viability, migration, and invasion of the cells under treatment of IORT-induced wound fluid (WF-RT) and the cells under surgery-induced wound fluid (WF) were compared. Our findings showed that cell viability was increased in spheroids under both WF treatments, whereas viability of the cell lines depended on the type of cells and incubation times. Both WFs significantly increased sub-G1 and arrested the cells in G0/G1 phases associated with increased P16 and P21 expression levels. The expression level of Caspase 3 in both cell culture systems and for both WF-treated groups was significantly increased. Furthermore, our results revealed that although the migration was increased in both systems of WF-treated cells compared to cell culture media-treated cells, E-cadherin expression was significantly increased only in the WF-RT group. In conclusion, WF-RT could not effectively inhibit tumor progression in an ex vivo tumor-on-chip model. Moreover, our data suggest that a microfluidic system could be a suitable 3D system to mimic in vivo tumor conditions than 2D cell culture.

Radiation therapy for triple-negative breast cancer: emerging role of microRNAs as biomarkers and radiosensitivity modifiers. A systematic review

PURPOSE

Radiation therapy (RT) for triple-negative breast cancer (TNBC) treatment is currently delivered in the adjuvant setting and is under investigation as a booster of neoadjuvant treatments. However, TNBC radioresistance remains an obstacle, so new biomarkers are needed to select patients for any integration of RT in the TNBC therapy sequence. MicroRNAs (miRs) are important regulators of gene expression, involved in cancer response to ionizing radiation (IR) and assessable by tumor tissue or liquid biopsy. This systematic review aimed to evaluate the relationships between miRs and response to radiation in TNBC, as well as their potential predictive and prognostic values.

METHODS

A thorough review of studies related to miRs and RT in TNBC was performed on PubMed, EMBASE, and Web of Science. We searched for original English articles that involved dysregulation of miRs in response to IR on TNBC-related preclinical and clinical studies. After a rigorous selection, 44 studies were chosen for further analysis.

RESULTS

Thirty-five miRs were identified to be TNBC related, out of which 21 were downregulated, 13 upregulated, and 2 had a double-side expression in this cancer. Expression modulation of many of these miRs is radiosensitizing, among which miR-7, -27a, -34a, -122, and let-7 are most studied, still only in experimental models. The miRs reported as most influencing/reflecting TNBC response to IR are miR-7, -27a, -155, -205, -211, and -221, whereas miR-21, -33a, -139-5p, and -210 are associated with TNBC patient outcome after RT.

CONCLUSION

miRs are emerging biomarkers and radiosensitizers in TNBC, worth further investigation. Dynamic assessment of circulating miRs could improve monitoring and TNBC RT efficacy, which are of particular interest in the neoadjuvant and the high-risk patients' settings.

Role of non-coding RNAs in response of breast cancer to radiation therapy

Breast cancer ranks as the first common cancer with a high incidence rate and mortality among women. Radiation therapy is the main therapeutic method for breast cancer patients. However, radiation resistance of tumor cells can reduce the efficacy of treatment and lead to recurrence and mortality in patients. Non-coding RNA (ncRNAs) refers to a group of small RNA molecules that are not translated into protein, while they have the ability to modulate the translation of target mRNA. Several studies have reported the altered expression of ncRNAs in response to radiation in breast cancer. NcRNAs have been found to influence on radiation response of breast cancer by regulating various mechanisms, including DNA damage response, cell cycle regulation, cell death, inflammatory response, cancer stem cell and EGFR related pathways. This paper aimed to provide a summary of current findings on ncRNAs dysregulation after irradiation. We also present the function and mechanism of ncRNAs in modulating radiosensitivity or radioresistance of breast cancer cells.

Non-Coding RNAs Associated With Radioresistance in Triple-Negative Breast Cancer

The resistance that Triple-Negative Breast Cancer (TNBC), the most aggressive breast cancer subtype, develops against radiotherapy is a complex phenomenon involving several regulators of cell metabolism and gene expression; understanding it is the only way to overcome it. We focused this review on the contribution of the two leading classes of regulatory non-coding RNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), against ionizing radiation-based therapies. We found that these regulatory RNAs are mainly associated with DNA damage response, cell death, and cell cycle regulation, although they regulate other processes like cell signaling and metabolism. Several regulatory RNAs regulate multiple pathways simultaneously, such as miR-139-5p, the miR-15 family, and the lncRNA HOTAIR. On the other hand, proteins such as CHK1 and WEE1 are targeted by several regulatory RNAs simultaneously. Interestingly, the study of miRNA/lncRNA/mRNA regulation axes increases, opening new avenues for understanding radioresistance. Many of the miRNAs and lncRNAs that we reviewed here can be used as molecular markers or targeted by upcoming therapeutic options, undoubtedly contributing to a better prognosis for TNBC patients.

Regulatory roles of miRNAs 16, 133a, and 223 on osteoclastic bone destruction caused by breast cancer metastasis

Osteolytic bone metastasis leads to skeletal-related events, resulting in a decline in the patient activities and survival; therefore, it is important to understand the mechanism underlying bone metastasis. Recent studies have suggested that microRNAs (miRNAs or miRs) are involved in osteoclast differentiation and/or osteolytic bone metastasis; however, the roles of miRNAs have not been elucidated. In the present study, the roles of miRNAs in bone destruction caused by breast cancer metastasis were investigated in vitro and in vivo. miR-16, miR-133a and miR-223 were transfected into a human breast cancer cell line, MDA-MB-231. The expression of osteolytic factors in conditioned medium (miR-CM) collected from the culture of transfected cells was assessed. To evaluate the effects of miRNAs on osteoclast differentiation and activities, tartrate-resistant acid phosphatase (TRAP) staining and bone resorptive assays were performed in osteoclasts following miR-CM treatment. To create in vivo bone metastasis models for histological and morphometric evaluation, miRNA-transfected MDA-MB-231 cells were transplanted into the proximal tibia of nude mice. Expression of osteolytic factors, including receptor activator for nuclear factor-κB ligand (RANKL), interleukin (IL)-1β, IL-6, parathyroid hormone-related protein (PTHrP), and tumor necrosis factor (TNF), was increased in miR-16-CM, whereas it was decreased in both miR-133a-CM and miR-223-CM. TRAP staining and bone resorptive assays revealed that osteoclast function and activities were promoted by miR-16-CM treatment, whereas they were suppressed by miR-133a-CM and miR-223-CM. Consistent with in vitro findings, in vivo experiments revealed that the overexpression of miR-16 increased osteoclast activities and bone destruction in MDA-MB-231 cells, whereas the opposite results were observed in both miR-133a- and miR-223-transfected MDA-MB-231 cells. Our results indicated that miR-16 promoted osteoclast activities and bone destruction caused by breast cancer metastasis in the bone microenvironment, whereas miR-133a and miR-223 suppressed them. These miRNAs could be potential biomarkers and therapeutic targets for breast cancer bone metastasis.

EGF-Induced miR-223 Modulates Goat Mammary Epithelial Cell Apoptosis and Inflammation via ISG15

The health of mammary gland is essential for lactation. Epidermal growth factor (EGF) is reported to play an important role in lactation initiation and miR-223 is a conserved microRNA in anti-inflammation. In this study, EGF was found to induce a higher expression of miR-223 in goat mammary epithelial cell (gMEC). The downstream genes of miR-223 were screened by RNA sequencing, including Interferon-stimulated gene product 15 (ISG15), a pivotal immune responder, which was detected to be downregulated by EGF and miR-223. Due to the correlation between inflammation and apoptosis, the gMEC apoptosis modulated by EGF, miR-223, and ISG15 was investigated, and the protein expressions of Bcl-2/Bax, Caspase 3 and p53 were examined to evaluate the apoptosis of gMEC. The protein expressions of p-STAT3/STAT3, PR, FOXC1, and HOXA10, which had been shown to be related to inflammation, were detected to assess the inflammation of gMEC. This study provided a regulation axis, EGF/miR-223/ISG15, and illustrated its regulation to gMEC apoptosis and inflammation.

The many facets of miR-223 in cancer: Oncosuppressor, oncogenic driver, therapeutic target, and biomarker of response

Given their intrinsic pleiotropism, microRNAs (miR) play complex biological roles, in both normal and pathological conditions. Often the same miR can act as oncogene or oncosuppressor, depending on the biological process dysregulated in each specific tissue. miR‐223 does not represent an exception to this rule and its functions greatly differ in different contexts. miR‐223 has been widely studied in the hematopoietic compartment, where it plays a central role in innate immune response, regulating myeloid differentiation and granulocytes function. Accordingly, dysregulated expression of miR‐223 has been associated to different inflammatory disorders and tumors arising from the immune compartment. Most carcinomas, breast cancer being the most studied, display loss of miR‐223. However, in gastro‐esophageal cancers miR‐223 is frequently overexpressed and correlates with worse prognosis. A link between miR‐223 and response to CDK4/6‐inhibitors has been recently proposed, suggesting a role as biomarker of therapeutic response. The notion that one of the most commonly mutated protein in cancer, mutant p53, binds the promoter of miR‐223 and suppresses its transcription, adds a further level of complexity to the full understanding of miR‐223 in cancer. In this review, we will summarize the current knowledge on the molecular networks that alter or are altered by miR‐223, in different cancer types. We will discuss if the times are ready for the exploitation of miR‐223 as predictive biomarker of treatment response or, even, as therapeutic target, in specific settings. Finally, we will suggest which could be the next steps to be taken for a realistic clinical application of miR‐223.

This article is categorized under:

RNA in Disease and Development > RNA in Disease

Intraoperative radiotherapy boost as part of breast-conservation therapy for breast cancer: a single-institution retrospective analysis

Background

There are currently no data from randomized controlled trials on the use of intraoperative radiotherapy (IORT) as a tumor bed boost as part of a breast-conservation approach for breast cancer. This study retrospectively reviewed the safety and efficacy of IORT as a boost treatment at a tertiary cancer center.

Methods

From 2015 to 2019, patients underwent breast-conserving surgery with axillary lymph node staging and a single dose of 20 Gy IORT with 50-kV photons, followed by whole-breast irradiation (WBI) and adjuvant systemic therapy (if applicable). Patients were followed for assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 5.0) at 3–6-month intervals. Outcomes included ipsilateral (IBTR) and contralateral breast progression-free survival (CBE), distant metastasis-free survival (DMFS), and overall survival (OS).

Results

Median follow-up for the 214 patients was 28 (range 2–59) months. Most patients had T1 disease (n = 124) and were clinically node negative. Only few patients had high-grade and/or triple-negative disease. The vast majority of patients underwent sentinel node biopsy, and 32 (15%) required re-resection for initially positive margins. Finally, all tumor bed margins were clear. Nine (4.2%) and 48 (22.4%) patients underwent neoadjuvant and adjuvant chemotherapy, respectively. WBI was predominantly performed as conventionally fractionated WBI (n = 187, 87.4%), and the median time from BCS to WBI was 54.5 days. IORT was delivered with a single dose of 20 Gy. The median WBI dose was 50 Gy (range 29.4–50.4 Gy). No patients experienced grade 4 events; acute grade 3 toxicities were limited to 17 (8%) cases of radiation dermatitis. Postoperative toxicities were mild. After WBI only one case of late grade ≥ 2 events was reported. There were two recurrences in the tumor bed and one contralateral breast event.

Conclusion

This investigation provides additional preliminary data supporting the using of IORT in the boost setting and corroborates the existing literature. These encouraging results should be prospectively validated by the eventual publication of randomized studies such as TARGIT‑B.

Wound Fluid from Breast Cancer Patients Undergoing Intraoperative Radiotherapy Exhibits an Altered Cytokine Profile and Impairs Mesenchymal Stromal Cell Function

Intraoperative radiotherapy (IORT) displays an increasingly used treatment option for early breast cancer. It exhibits non-inferiority concerning the risk of recurrence compared to conventional external irradiation (EBRT) in suitable patients with early breast cancer. Since most relapses occur in direct proximity of the former tumor site, the reduction of the risk of local recurrence effected by radiotherapy might partially be due to an alteration of the irradiated tumor bed's micromilieu. Our aim was to investigate if IORT affects the local micromilieu, especially immune cells with concomitant cytokine profile, and if it has an impact on growth conditions for breast cancer cells as well as mammary mesenchymal stromal cells (MSC), the latter considered as a model of the tumor bed stroma.42 breast cancer patients with breast-conserving surgery were included, of whom 21 received IORT (IORT group) and 21 underwent surgery without IORT (control group). Drainage wound fluid (WF) was collected from both groups 24 h after surgery for flow cytometric analysis of immune cell subset counts and potential apoptosis and for multiplex cytokine analyses (cytokine array and ELISA). It served further as a supplement in cultures of MDA-MB 231 breast cancer cells and mammary MSC for functional analyses, including proliferation, wound healing and migration. Furthermore, the cytokine profile within conditioned media from WF-treated MSC cultures was assessed. Flow cytometric analysis showed no group-related changes of cell count, activation state and apoptosis rates of myeloid, lymphoid leucocytes and regulatory T cells in the WF. Multiplex cytokine analysis of the WF revealed group-related differences in the expression levels of several cytokines, e.g., oncostatin-M, leptin and IL-1β. The application of WF in MDA-MB 231 cultures did not show a group-related difference in proliferation, wound healing and chemotactic migration. However, WF from IORT-treated patients significantly inhibited mammary MSC proliferation, wound healing and migration compared to WF from the control group. The conditioned media collected from WF-treated MSC-cultures also exhibited altered concentrations of VEGF, RANTES and GROα. IORT causes significant changes in the cytokine profile and MSC growth behavior. These changes in the tumor bed could potentially contribute to the beneficial oncological outcome entailed by this technique. The consideration whether this alteration also affects MSC interaction with other stroma components presents a promising gateway for future investigations.

High Expression of microRNA-223 Indicates a Good Prognosis in Triple-Negative Breast Cancer

Purpose

MicroRNAs can influence many biological processes and have shown promise as cancer biomarkers. Few studies have focused on the expression of microRNA-223 (miR-223) and its precise role in breast cancer (BC). We aimed to examine the expression level of miR-223 and its prognostic value in BC.

Methods

Tissue microarray (TMA)-based miRNA detection in situ hybridization (ISH) with a locked nucleic acid (LNA) probe was used to detect miR-223 expression in 450 BC tissue samples. Overall survival (OS) and disease-free survival (DFS) were compared between two groups using the Kaplan-Meier method and Cox regression model.

Results

OS and DFS were prolonged in the high miR-223 expression group compared to the low miR-223 expression group (p < 0.0001 and p = 0.017, respectively), especially in patients with the triple-negative breast cancer (TNBC) subtype (p = 0.046 and p < 0.001, respectively). Univariate and multivariate Cox regression analyses revealed that TNM stage (p = 0.008), the molecular subtype (p = 0.049), and miR-223 (p < 0.001) were independently associated with OS and DFS. External validation was performed with the METABRIC and The Cancer Genome Atlas (TCGA) databases via online webtools and was consistent with the data described above.

Conclusions

This study provides evidence that high miR-223 expression at diagnosis is associated with improved DFS and OS for BC patients, especially those with the TNBC subtype. miR-223 is a valid and independent prognostic biomarker in BC.

Changes in peripheral immune cells after intraoperative radiation therapy in low-risk breast cancer

A detailed understanding of the interactions and the best dose-fractionation scheme of radiation to maximize antitumor immunity have not been fully established. In this study, the effect on the host immune system of a single dose of 20 Gy through intraoperative radiation therapy (IORT) on the surgical bed in low-risk breast cancer patients undergoing conserving breast cancer has been assessed. Peripheral blood samples from 13 patients were collected preoperatively and at 48 h and 3 and 10 weeks after the administration of radiation. We performed a flow cytometry analysis for lymphocyte subpopulations, natural killer cells (NK), regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSCs). We observed that the subpopulation of NK CD56+high CD16+ increased significantly at 3 weeks after IORT (0.30-0.42%, P < 0.001), while no changes were found in immunosuppressive profile, CD4+CD25+Foxp3+Helios+ Treg cells, granulocytic MDSCs (G-MDSCs) and monocytic MDSCs (Mo-MDSCs). A single dose of IORT may be an effective approach to improve antitumor immunity based on the increase in NK cells and the non-stimulation of immunosuppressive cells involved in immune escape. These findings support future combinations of IORT with immunotherapy, if they are confirmed in a large cohort of breast cancer patients.

Emerging role of non-coding RNAs in response of cancer cells to radiotherapy

Radiotherapy is an effective method for treatment of a large proportion of human cancers. Yet, the efficacy of this method is precluded by the induction of radioresistance in tumor cells and the radiation-associated injury of normal cells surrounding the field of radiation. These restrictions necessitate the introduction of modalities for either radiosensitization of cancer cells or protection of normal cells against adverse effects of radiation. Non-coding RNAs (ncRNAs) have essential roles in the determination of radiosensitivity. Moreover, ncRNAs can modulate radiation-induced side effects in normal cells. Several microRNAs (miRNAs) such as miR-620, miR-21 and miR-96-5p confer radioresistance, while other miRNAs including miR-340/ 429 confer radiosensitivity. The expression levels of a number of miRNAs are associated with radiation-induced complications such as lung fibrosis or oral mucositis. The expression patterns of several long non-coding RNAs (lncRNAs) such as MALAT1, LINC00630, HOTAIR, UCA1 and TINCR are associated with response to radiotherapy. Taken together, lncRNAs and miRNAs contribute both in modulation of response of cancer cells to radiotherapy and in protection of normal cells from the associated side effects. The current review provides an overview of the roles of these transcripts in these aspects.

CDKN1B mutation and copy number variation are associated with tumor aggressiveness in luminal breast cancer

The CDKN1B gene, encoding for the CDK inhibitor p27^kip1, is mutated in defined human cancer subtypes, including breast, prostate carcinomas and small intestine neuroendocrine tumors. Lessons learned from small intestine neuroendocrine tumors suggest that CDKN1B mutations could be subclonal, raising the question of whether a deeper sequencing approach could lead to the identification of higher numbers of patients with mutations. Here, we addressed this question and analyzed human cancer biopsies from breast (n = 396), ovarian (n = 110) and head and neck squamous carcinoma (n = 202) patients, using an ultra‐deep sequencing approach. Notwithstanding this effort, the mutation rate of CDKN1B remained substantially aligned with values from the literature, showing that essentially only hormone receptor‐positive breast cancer displayed CDKN1B mutations in a relevant number of cases (3%). However, the analysis of copy number variation showed that another fraction of luminal breast cancer displayed loss (8%) or gain (6%) of the CDKN1B gene, further reinforcing the idea that the function of p27^kip1 is important in this type of tumor. Intriguingly, an enrichment for CDKN1B alterations was found in samples from premenopausal luminal breast cancer patients (n = 227, 4%) and in circulating cell‐free DNA from metastatic luminal breast cancer patients (n = 59, 8.5%), suggesting that CDKN1B alterations could correlate with tumor aggressiveness and/or occur later during disease progression. Notably, many of the identified somatic mutations resulted in p27^kip1 protein truncation, leading to loss of most of the protein or of its C‐terminal domain. Using a gene‐editing approach in a luminal breast cancer cell line, MCF‐7, we observed that the expression of p27^kip1 truncating mutants that lose the C‐terminal domains failed to rescue most of the phenotypes induced by CDKN1B gene knockout, indicating that the functions retained by the C‐terminal portion are critical for its role as an oncosuppressor, at least in luminal breast cancer. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Synthesis and Characterization of Green Zinc Oxide Nanoparticles with Antiproliferative Effects through Apoptosis Induction and MicroRNA Modulation in Breast Cancer Cells

Changes in the expression of microRNAs can affect cancer cells' viability and behavior and the impact on cancer treatment. In this study, the expression of miR-155-5p, miR-203a-3p, and miR-223-3p in the MCF7 cancer cell line was studied when exposed to ZnO nanoparticles synthesized through a green route. Mentioned ZnO-NPs were well characterized by UV-vis spectroscopy, DLS, XRD, FTIR, FE-SEM, EDX, zeta potential, and AFM analyses. Cellular studies were conducted using ZnO-NPs before miRNA investigations including MTT cytotoxicity test against MCF7, MDA-MB-231, and HFF cell lines. Moreover, apoptosis assays were performed using morphological analysis, fluorescent dyes, flow cytometry, and evaluation of caspase-3 and caspase-8 gene expression. Biological properties such as the antioxidant and antimicrobial activity of these novel ZnO-NPs were considered. MTT assays showed that the inhibitory concentration (IC50) of ZnO-NPs after 24 h was 11.16 μg/mL, 60.08 μg/mL, and 26.3 μg/mL on MCF7, MDA-MB-231, and HFF cells, respectively. The qRT-PCR results showed reduced expression of miR-155-5p, miR-203a-3p, and miR-223-3p when the MCF7 cells were treated with the IC50 concentration of ZnO-NPs (11.16 μg/mL). The antioxidant activity results showed EC50 values at 57.19 μg/mL and 31.5 μg/mL in DPPH and ABTS assays, respectively. The antimicrobial activity of ZnO-NPs was determined on Gram-negative and Gram-positive bacterial strains and fungi using MIC and MBC assays. These NPs had a significant effect in reducing the expression of microRNAs in breast cancer cells. Finally, ZnO-NPs exerted antioxidant and antimicrobial activities.

Upregulation of CCT-3 Induces Breast Cancer Cell Proliferation Through miR-223 Competition and Wnt/β-Catenin Signaling Pathway Activation

The clinical significance and the function of chaperonin-containing TCP1 complex 3 (CCT-3) in breast cancer remain unknown. In this study, we found that CCT-3 was markedly overexpressed in breast cancer tissues. Statistical analysis revealed a significant correlation of CCT-3 expression with advanced breast cancer clinical stage and poorer survival. Ablation of CCT-3 knocked down the proliferation and the tumorigenicity of breast cancer cells in vitro and in vivo. CCT-3 may regulate breast cancer cell proliferation through a ceRNA network between miR-223 and β-catenin, thus affecting Wnt/β-catenin signaling pathway activation. We also validated that CCT-3 and β-catenin are novel direct targets of tumor suppressor miR-223. Our results suggest that both mRNA and the protein levels of CCT-3 are potential diagnosis biomarkers and therapeutic targets for breast cancer.

Bta-miR-223 Targeting CBLB Contributes to Resistance to Staphylococcus aureus Mastitis Through the PI3K/AKT/NF-κB Pathway

Bovine mastitis is an inflammatory condition of the mammary gland often caused by (Staphylococcus aureus) S. aureus infection. The aim of this study was to identify mastitis-related miRNAs and their downstream target genes, and therefore elucidate the regulatory mechanisms involved in disease progression and resistance. Three healthy and three mastitic cows were identified on the basis of the somatic cell count and bacterial culture of their milk, and the histological examination of udder tissues. High-throughput RNA sequencing and bioinformatic analyses revealed that 48 differentially expressed miRNAs (DEMs) in the mastitic udder tissues relative to the healthy tissues. Among 48 DEMs, the expression level of bta-miR-223 was the most up-regulated. Overexpression of the bta-miR-223 in Mac-T cells mitigated the inflammatory pathways induced by S. aureus-derived lipoteichoic acid (LTA). The Cbl proto-oncogene B (CBLB) was identified as the target gene of bta-miR-223, and the direct binding of the miRNA to the CBLB promoter was confirmed by dual luciferase reporter assay using wild-type and mutant 3'-UTR constructs. Furthermore, overexpression of CBLB in the LTA-stimulated Mac-T cells significantly upregulated PI3K, AKT, and phosphorylated NF-κB p65, whereas CBLB knockdown had the opposite effect. Consistent with the in vitro findings, the mammary glands of mice infected with 10⁸CFU/100 μL S. aureus showed high levels of CBLB, PI3K, AKT, and p-NF-κB p65 48 h after infection. Taken together, bta-miR-223 is a predominant miRNA involved in mastitis, and bta-miR-223 likely mitigates the inflammatory progression by targeting CBLB and inhibiting the downstream PI3K/AKT/NF-κB pathway.

Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomised clinical trial

OBJECTIVE

To determine whether risk adapted intraoperative radiotherapy, delivered as a single dose during lumpectomy, can effectively replace postoperative whole breast external beam radiotherapy for early breast cancer.

DESIGN

Prospective, open label, randomised controlled clinical trial.

SETTING

32 centres in 10 countries in the United Kingdom, Europe, Australia, the United States, and Canada.

PARTICIPANTS

2298 women aged 45 years and older with invasive ductal carcinoma up to 3.5 cm in size, cN0-N1, eligible for breast conservation and randomised before lumpectomy (1:1 ratio, blocks stratified by centre) to either risk adapted targeted intraoperative radiotherapy (TARGIT-IORT) or external beam radiotherapy (EBRT).

INTERVENTIONS

Random allocation was to the EBRT arm, which consisted of a standard daily fractionated course (three to six weeks) of whole breast radiotherapy, or the TARGIT-IORT arm. TARGIT-IORT was given immediately after lumpectomy under the same anaesthetic and was the only radiotherapy for most patients (around 80%). TARGIT-IORT was supplemented by EBRT when postoperative histopathology found unsuspected higher risk factors (around 20% of patients).

MAIN OUTCOME MEASURES

Non-inferiority with a margin of 2.5% for the absolute difference between the five year local recurrence rates of the two arms, and long term survival outcomes.

RESULTS

Between 24 March 2000 and 25 June 2012, 1140 patients were randomised to TARGIT-IORT and 1158 to EBRT. TARGIT-IORT was non-inferior to EBRT: the local recurrence risk at five year complete follow-up was 2.11% for TARGIT-IORT compared with 0.95% for EBRT (difference 1.16%, 90% confidence interval 0.32 to 1.99). In the first five years, 13 additional local recurrences were reported (24/1140 v 11/1158) but 14 fewer deaths (42/1140 v 56/1158) for TARGIT-IORT compared with EBRT. With long term follow-up (median 8.6 years, maximum 18.90 years, interquartile range 7.0-10.6) no statistically significant difference was found for local recurrence-free survival (hazard ratio 1.13, 95% confidence interval 0.91 to 1.41, P=0.28), mastectomy-free survival (0.96, 0.78 to 1.19, P=0.74), distant disease-free survival (0.88, 0.69 to 1.12, P=0.30), overall survival (0.82, 0.63 to 1.05, P=0.13), and breast cancer mortality (1.12, 0.78 to 1.60, P=0.54). Mortality from other causes was significantly lower (0.59, 0.40 to 0.86, P=0.005).

CONCLUSION

For patients with early breast cancer who met our trial selection criteria, risk adapted immediate single dose TARGIT-IORT during lumpectomy was an effective alternative to EBRT, with comparable long term efficacy for cancer control and lower non-breast cancer mortality. TARGIT-IORT should be discussed with eligible patients when breast conserving surgery is planned.

TRIAL REGISTRATION

ISRCTN34086741, NCT00983684.

RASA1 inhibits the progression of renal cell carcinoma by decreasing the expression of miR-223-3p and promoting the expression of FBXW7

RAS p21 protein activator 1 (RASA1), also known as p120-RasGAP, is a RasGAP protein that functions as a signaling scaffold protein, regulating pivotal signal cascades. However, its biological mechanism in renal cell carcinoma (RCC) remains unknown. In the present study, RASA1, F-box/WD repeat-containing protein 7 (FBXW7), and miR-223-3p expression were assessed via quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. Then, the targeted correlations of miR-223-3p with FBXW7 and RASA1 were verified via a dual-luciferase reporter gene assay. CCK-8, flow cytometry, and Transwell assays were implemented independently to explore the impact of RASA1 on cell proliferation, apoptosis, migration, and cell cycle progression. Finally, the influence of RASA1 on tumor formation in RCC was assessed in vivo through the analysis of tumor growth in nude mice. Results showed that FBXW7 and RASA1 expression were decreased in RCC tissues and cell lines, while miR-223-3p was expressed at a higher level. Additionally, FBXW7 and RASA1 inhibited cell proliferation but facilitated the population of RCC cells in the G0/G1 phase. Altogether, RASA1 may play a key role in the progression of RCC by decreasing miR-223-3p and subsequently increasing FBXW7 expression.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

Effect of Delayed Targeted Intraoperative Radiotherapy vs Whole-Breast Radiotherapy on Local Recurrence and Survival: Long-term Results From the TARGIT-A Randomized Clinical Trial in Early Breast Cancer

Importance

Conventional adjuvant radiotherapy for breast cancer given daily for several weeks is onerous and expensive. Some patients may be obliged to choose a mastectomy instead, and some may forgo radiotherapy altogether. We proposed a clinical trial to test whether radiotherapy could be safely limited to the tumor bed.

Objective

To determine whether delayed second-procedure targeted intraoperative radiotherapy (TARGIT-IORT) is noninferior to whole-breast external beam radiotherapy (EBRT) in terms of local control.

Design, Setting, and Participants

In this prospective, randomized (1:1 ratio) noninferiority trial, 1153 patients aged 45 years or older with invasive ductal breast carcinoma smaller than 3.5 cm treated with breast conservation were enrolled from 28 centers in 9 countries. Data were locked in on July 3, 2019.

Interventions

The TARGIT-A trial was started in March 2000; patients were randomized after needle biopsy to receive TARGIT-IORT immediately after lumpectomy under the same anesthetic vs EBRT and results have been shown to be noninferior. A parallel study, described in this article, was initiated in 2004; patients who had their cancer excised were randomly allocated using separate randomization tables to receive EBRT or delayed TARGIT-IORT given as a second procedure by reopening the lumpectomy wound.

Main Outcomes and Measures

A noninferiority margin for local recurrence rate of 2.5% at 5 years, and long-term survival outcomes.

Results

Overall, 581 women (mean [SD] age, 63 [7] years) were randomized to delayed TARGIT-IORT and 572 patients (mean [SD] age, 63 [8] years) were randomized to EBRT. Sixty patients (5%) had tumors larger than 2 cm, or had positive nodes and only 32 (2.7%) were younger than 50 years. Delayed TARGIT-IORT was not noninferior to EBRT. The local recurrence rates at 5-year complete follow-up were: delayed TARGIT-IORT vs EBRT (23/581 [3.96%] vs 6/572 [1.05%], respectively; difference, 2.91%; upper 90% CI, 4.4%). With long-term follow-up (median [IQR], 9.0 [7.5-10.5] years), there was no statistically significant difference in local recurrence-free survival (HR, 0.75; 95% CI, 0.57-1.003; P = .052), mastectomy-free survival (HR, 0.88; 95% CI, 0.65-1.18; P = .38), distant disease-free survival (HR, 1.00; 95% CI, 0.72-1.39; P = .98), or overall survival (HR, 0.96; 95% CI, 0.68-1.35; P = .80).

Conclusions and Relevance

These long-term data show that despite an increase in the number of local recurrences with delayed TARGIT-IORT, there was no statistically significant decrease in mastectomy-free survival, distant disease-free survival, or overall survival.

Trial Registration

ISRCTN34086741, ClinicalTrials.gov Identifier: NCT00983684.

Differential miRNAs expression pattern of irradiated breast cancer cell lines is correlated with radiation sensitivity

Radiotherapy is a fundamental step in the treatment of breast cancer patients. The treatment efficiency is however reduced by the possible onset of radiation resistance. In order to develop the effective treatment approach, it is important to understand molecular basis of radiosensitivity in breast cancer. The purpose of the present study was to investigate different radiation response of breast cancer cell lines, and find out if this response may be related to change in the microRNAs expression profile. MDA-MB-231 and T47D cells were subjected to different doses of radiation, then MTT and clonogenic assays were performed to assess radiation sensitivity. Cytofluorometric and western blot analysis were performed to gain insight into cell cycle distribution and protein expression. MicroRNA sequencing and bioinformatics prediction methods were used to identify the difference in microRNAs expression between two breast cancer cells and the related genes and pathways. T47D cells were more sensitive to radiation respect to MDA-MB-231 cells as demonstrated by a remarkable G2 cell cycle arrest followed by a greater reduction in cell viability and colony forming ability. Accordingly, T47D cells showed higher increase in the phosphorylation of ATM, TP53 and CDK1 (markers of radiation response) and faster and more pronounced increase in RAD51 and γH2AX expression (markers of DNA damage), when compared to MDA-MB-231 cells. The two cell lines had different microRNAs expression profiles with a confirmed significant differential expression of miR-16-5p, which targets cell cycle related genes and predicts longer overall survival of breast cancer patients, as determined by bioinformatics analysis. These results suggest a possible role for miR-16-5p as radiation sensitizing microRNA and as prognostic/predictive biomarker in breast cancer.

The actual benefit of intraoperative radiation therapy using 50 kV x-rays in early breast cancer: A retrospective study of 676 patients

This French study reports the 5-year results of partial-breast irradiation using intraoperative radiation therapy (IORT) with 50 kV x-rays, in select early breast cancer patients. We report a retrospective analysis of 676 consecutive early breast cancer patients treated between November 2011 and December 2015 by partial-breast irradiation using the INTRABEAM^® system. Patients were highly selected based on the ASTRO and GEC-ESTRO criteria and underwent breast-conservative surgery and IORT, completed with additional whole-breast irradiation (WBI) when unexpected unfavorable prognostic factors were found at the final pathology report. Patients' outcomes relative to local and distant control, overall and breast cancer-specific survival, and toxicity are presented, as well as rates of additional WBI. Additional WBI was mandatory in one third of patients (31%), mainly due to lymph node involvement and extensive intraductal component. With a median follow-up time of 54 months, the 5-year local recurrence rate was 1.7% [95%CI: 0.9-3.3]; the median time to local recurrence was 23 months; ipsilateral breast recurrences mainly occurred in the same quadrant (7/11); in the restricted population, meeting all predefined criteria and treated with IORT alone (406 patients), the local recurrence rate was 1.5% [95%CI: 0.6-3.6]. Five-year distant tumor control was 98.6% [95%CI: 97.2-99.3], and the median time to distant recurrence was 22 months. Five-year overall survival was 96.5% [95%CI: 94.2-97.8], and 5-year breast cancer-specific survival was 98.9% [95%CI: 97.6-99.7]. In patients treated with IORT alone, there was no grade 3 toxicity, only four grade 3 (mainly fibrosis) affected patients treated with IORT and WBI. Grade 1-2 toxicity rates were 14% and 34.4% in patients treated with IORT alone and IORT plus WBI, respectively. Partial-breast irradiation using IORT by a 50 kV photon device is safe and well-tolerated in select patients with early breast cancer and is a valuable option in patients reluctant for adjuvant WBI.

Targeting Epigenetic Dependencies in Solid Tumors: Evolutionary Landscape Beyond Germ Layers Origin

Extensive efforts recently witnessed the complexity of cancer biology; however, molecular medicine still lacks the ability to elucidate hidden mechanisms for the maintenance of specific subclasses of rare tumors characterized by the silent onset and a poor prognosis (e.g., ovarian cancer, pancreatic cancer, and glioblastoma). Recent mutational fingerprints of human cancers highlighted genomic alteration occurring on epigenetic modulators. In this scenario, the epigenome dependency of cancer orchestrates a broad range of cellular processes critical for tumorigenesis and tumor progression, possibly mediating escaping mechanisms leading to drug resistance. Indeed, in this review, we discuss the pivotal role of chromatin remodeling in shaping the tumor architecture and modulating tumor fitness in a microenvironment-dependent context. We will also present recent advances in the epigenome targeting, posing a particular emphasis on how this knowledge could be translated into a feasible therapeutic approach to individualize clinical settings and improve patient outcomes.

miRNAs as radio-response biomarkers for breast cancer stem cells

In breast cancer (BC), the presence of cancer stem cells (CSCs) has been related to relapse, metastasis, and radioresistance. Radiotherapy (RT) is an extended BC treatment, but is not always effective. CSCs have several mechanisms of radioresistance in place, and some miRNAs are involved in the cellular response to ionizing radiation (IR). Here, we studied how IR affects the expression of miRNAs related to stemness in different molecular BC subtypes. Exposition of BC cells to radiation doses of 2, 4, or 6 Gy affected their phenotype, functional characteristics, pluripotency gene expression, and in vivo tumorigenic capacity. This held true for various molecular subtypes of BC cells (classified by ER, PR and HER‐2 status), and for BC cells either plated in monolayer, or being in suspension as mammospheres. However, the effect of IR on the expression of eight stemness‐ and radioresistance‐related miRNAs (miR‐210, miR‐10b, miR‐182, miR‐142, miR‐221, miR‐21, miR‐93, miR‐15b) varied, depending on cell line subpopulation and clinicopathological features of BC patients. Therefore, clinicopathological features and, potentially also, chemotherapy regimen should be both taken into consideration, for determining a potential miRNA signature by liquid biopsy in BC patients treated with RT. Personalized and precision RT dosage regimes could improve the prognosis, treatment, and survival of BC patients.

Identification of miRNA-Based Signature as a Novel Potential Prognostic Biomarker in Patients with Breast Cancer

To identify the novel, noninvasive biomarkers to assess the outcome and prognosis of breast cancer (BC), patients with high sensitivity and specificity are greatly desired. Herein, the miRNA expression profile and matched clinical features of BC patients were extracted from The Cancer Genome Atlas (TCGA) database. The preliminary candidates were screened out by the univariate Cox regression test. Then, with the help of LASSO Cox regression analysis, the hsa-let-7b, hsa-mir-101-2, hsa-mir-135a-2, hsa-mir-22, hsa-mir-30a, hsa-mir-31, hsa-mir-3130-1, hsa-mir-320b-1, hsa-mir-3678, hsa-mir-4662a, hsa-mir-4772, hsa-mir-493, hsa-mir-556, hsa-mir-652, hsa-mir-6733, hsa-mir-874, and hsa-mir-9-3 were selected to construct the overall survival (OS) predicting signature, while the hsa-mir-130a, hsa-mir-204, hsa-mir-217, hsa-mir-223, hsa-mir-24-2, hsa-mir-29b-1, hsa-mir-363, hsa-mir-5001, hsa-mir-514a-1, hsa-mir-624, hsa-mir-639, hsa-mir-659, and hsa-mir-6892 were adopted to establish the recurrence-free survival (RFS) predicting signature. Referring to the median risk scores generated by the OS and RFS formulas, respectively, subgroup patients with high risk were strongly related to a poor OS and RFS revealed by Kaplan-Meier (K-M) plots. Meanwhile, receiver operating curve (ROC) analysis validated the accuracy and stability of these two signatures. When stratified by clinical features, such as tumor stage, age, and molecular subtypes, we found that the miRNA-based OS and RFS classifiers were still significant in predicting OS/RFS and showed the best predictive values than any other features. Besides, functional prediction analyses showed that these targeted genes of the enrolled miRNAs were enriched in cancer-associated pathways, such as MAPK/RTK, Ras, and PI3K-Akt signaling pathways. In summary, our observations demonstrate that the novel miRNA-based OS and RFS signatures are independent prognostic indicators for BC patients and worthy to be validated by further prospective studies.

Downregulation of miR-223 Expression Is an Early Event during Mammary Transformation and Confers Resistance to CDK4/6 Inhibitors in Luminal Breast Cancer

miR-223 is an anti-inflammatory miRNA that in cancer acts either as an oncosuppressor or oncopromoter, in a context-dependent manner. In breast cancer, we demonstrated that it dampens the activation of the EGF pathway. However, little is known on the role of miR-223 during breast cancer onset and progression. miR-223 expression was decreased in breast cancer of luminal and HER2 subtypes and inversely correlated with patients' prognosis. In normal luminal mammary epithelial cells, miR-223 acted cell autonomously in the control of their growth and morphology in three-dimensional context. In the MMTV-Δ16HER2 transgenic mouse model, oncogene transformation resulted in a timely abrogation of miR-223 expression, likely due to activation of E2F1, a known repressor of miR-223 transcription. Accordingly, treatment with CDK4/6 inhibitors, which eventually results in restraining E2F1 activity, restored miR-223 expression and miR-223 ablation induced luminal breast cancer resistance to CDK4/6 inhibition, both in vitro and in vivo. Notably, miR-223 expression was lost in microdissected ductal carcinoma in situ (DCIS) from patients with luminal and HER2-positive breast cancer. Altogether, these results identify downmodulation of miR-223 as an early step in luminal breast cancer onset and suggest that it could be used to identify aggressive DCIS and predict the response to targeted therapy. SIGNIFICANCE: miR-223 may represent a predictive biomarker of response to CDK4/6 inhibitors and its loss could identify DCIS lesions that are likely to progress into invasive breast cancer.

MiR-223-3p targeting epithelial cell transforming sequence 2 oncogene inhibits the activity, apoptosis, invasion and migration of MDA-MB-468 breast cancer cells

Purpose

This research was to investigate the role of miR-223-3p targeting epithelial cell transforming sequence 2 oncogene (ECT2) in activity, apoptosis, invasion and migration of MDA-MB-468 breast cancer (BC) cells.

Methods

The human BC cell lines MDA-MB-468 were used for the experiment. They were divided into six groups: blank group (no plasmid transfection), NC group (negative control, transfected empty plasmid), miR-223-3p mimic group (transfected miR-223-3p mimic plasmid), miR-223-3p inhibitor group (transfected miR-223-3p inhibitor plasmid), si-ECT2 group (transfected si ECT2 plasmid) and miR-223-3p mimic+oe-ECT2 group (transfected with miR-223-3p mimic plasmid and ECT2 plasmid).

Results

Compared with the NC group, the mRNA and protein expression of Bax in miR-223-3p mimic and si-ECT2 groups were significantly increased, while the mRNA and protein expression of ECT2, Bcl-2, vascular endothelial growth factor (VEGF), and TGF-β1 were significantly decreased (all P<0.05). Compared with the NC group, the expression of miR-223-3p and the mRNA and protein expression of Bax were significantly decreased in the miR-223-3p inhibitor group, while the mRNA and protein expression of ECT2, Bcl-2, VEGF and TGF-β1 were significantly increased (both P<0.05). Compared with the single processing group, the mRNA and protein expression of Bax in the miR-223-3p mimic+si-ECT2 group were significantly increased, while the mRNA and protein expression of ECT2, Bcl-2, VEGF, and TGF-β1 were significantly decreased (all P<0.05).

Conclusion

MiR-223-3p targets and inhibits the expression of ECT2, thus inhibiting the invasion and migration of BC cells, and promoting cell apoptosis. miR-223-3p plays a protective role in BC.

Long-term changes in blood counts after intraoperative radiotherapy for breast cancer-single center experience and review of the literature

Background

Intraoperative radiotherapy (IORT) for breast cancer is used as an upfront boost or as accelerated partial breast irradiation (APBI). To date, no description of blood count changes after IORT are available. Our analysis shows blood count changes in breast cancer patients up to 5 years after IORT ± whole breast radiotherapy (WBRT).

Methods

IORT was given as APBI in 58 patients (IORT/APBI-group) and as a boost in 198 patients (IORT/WBRT-group). A median dose of 20 Gy was given intraoperatively with low energy X-rays [INTRABEAM (TM) System] and additionally 46 Gy/2 Gy per fraction to the whole breast, if WBRT was added. Blood counts were collected preoperatively, after 90 days and through year 1–5 of follow-up. Dunnett’s tests were used to calculate changes in blood counts over time. Additionally, platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and derived neutrophil-to-lymphocyte ratio (dNLR) were calculated for each time point.

Results

Significantly decreases in the IORT/WBRT-group were seen for erythrocytes, hemoglobin, platelets and leucocytes and an increase for lymphocytes for the total follow-up period. In the IORT/APBI-group significantly decreases were seen for erythrocytes and hemoglobin for the total follow-up period. Regarding changes during follow-up compared to the preoperative value, much more significant changes were seen in the IORT/WBRT-group compared to IORT/APBI-group without any relevant impact of chemotherapy. Regarding PLR-, NLR- and dNLR-values the rate of patients over the range improved over time in both groups.

Conclusions

IORT/APBI seems to have a smaller effect on blood counts compared to IORT/WBRT. Furthermore, PLR-, NLR- and dNLR-values improved over time, suggesting a positive effect on outcome after IORT in general.

Wound fluids collected postoperatively from patients with breast cancer induce epithelial to mesenchymal transition but intraoperative radiotherapy impairs this effect by activating the radiation-induced bystander effect

Wound fluids (WF) are believed to play a role in the local recurrences by inducing an inflammatory process in scar tissue area. Given that most local relapse in primary breast cancer patients occur within the scar tissue area, researchers have investigated whether localized radiotherapy, such as intraoperative radiotherapy (IORT), could be more effective than postoperative RT in inhibiting local tumor recurrence. The epithelial-mesenchymal transition (EMT) program plays a critical role in promoting metastasis in epithelium-derived carcinoma. Given this background the main aim of the present study was to determine the mechanisms by which IORT decreases the tumorigenic potential of WF. We assumed that postoperative fluids from patients would activate the radiation-induced bystander effect (RIBE) in treated cells, thus altering the tumor microenvironment. To confirm this hypothesis, WF collected from patients after breast conserving surgery (BCS) alone, after BCS followed by IORT treatment or WF from BCS patients together with RIBE medium were incubated with MCF7 and MDA-MB-468 cells. Changes in the CSC phenotype, in EMT program and potential to migrate were performed to determine the possible role of WF on the migration of breast cancer cells. Our findings show that wound fluids stimulate the CSC phenotype and EMT program in breast cancer cell lines. This effect was partially abrogated when the cells were incubated in wound fluids collected from patients after breast-conserving surgery followed by IORT. Additionally, we confirmed the role of radiation-induced bystander effect in altering the properties of the WF to induce the CSC phenotype and EMT program.

miR-223-RhoB signaling pathway regulates the proliferation and apoptosis of colon adenocarcinoma

MicroRNAs (miRNAs) can function as tumor suppressor or oncogenic genes. The putative targets of miR-223 include tumor suppressor gene, RhoB. Here we sought to investigate the role of miR-223-RhoB signaling pathway in proliferation of colon cancer. We used Western blot, immunofluorescence staining, or RT-PCR to detect expression levels of miR-223 and RhoB in colon adenocarcinoma and adjacent non-cancerous tissue samples, or in human colon adenocarcinoma cell lines. MTT assay was used to determine proliferation and apoptosis in cell lines. We further used Western blot to determine levels of cell cycle regulators CDK1 and Cyclin B1 with anti-miR-223 or apoptosis with overexpression of RhoB. The expression level of miR-223 was significantly upregulated in clinical samples and cell lines of colon adenocarcinoma, in contrast to down-regulation of RhoB. In addition, we showed that inhibition of miR-223 led to upregulation of RhoB and in turn suppression of proliferation of colon adenocarcinoma. Moreover, inhibition of miR-223 or overexpression of RhoB induced cell arrest or apoptosis in colon adenocarcinoma. These results suggest that miR-223-RhoB signaling pathway plays an important role in modulation of proliferation, cell arrest, and apoptosis in colon cancer.

Intraoperative Radiotherapy for Breast Cancer

Intraoperative radiotherapy (IORT) for early stage breast cancer is a technique for partial breast irradiation. There are several technologies in clinical use to perform breast IORT. Regardless of technique, IORT generally refers to the delivery of a single dose of radiation to the periphery of the tumor bed in the immediate intraoperative time frame, although some protocols have performed IORT as a second procedure. There are two large prospective randomized trials establishing the safety and efficacy of breast IORT in early stage breast cancer patients with sufficient follow-up time on thousands of women. The advantages of IORT for partial breast irradiation include: direct visualization of the target tissue ensuring treatment of the high-risk tissue and eliminating the risk of marginal miss; the use of a single dose coordinated with the necessary surgical excision thereby reducing omission of radiation and the selection of mastectomy for women without access to a radiotherapy facility or unable to undergo several weeks of daily radiation; favorable toxicity profiles; patient convenience and cost savings; radiobiological and tumor microenvironment conditions which lead to enhanced tumor control. The main disadvantage of IORT is the lack of final pathologic information on the tumor size, histology, margins, and nodal status. When unexpected findings on final pathology such as positive margins or positive sentinel nodes predict a higher risk of local or regional recurrence, additional whole breast radiation may be indicated, thereby reducing some of the convenience and low-toxicity advantages of sole IORT. However, IORT as a tumor bed boost has also been studied and appears to be safe with acceptable toxicity. IORT has potential efficacy advantages related to overall survival related to reduced cardiopulmonary radiation doses. It may also be very useful in specific situations, such as prior to oncoplastic reconstruction to improve accuracy of adjuvant radiation delivery, or when used as a boost in higher risk patients to improve tumor control. Ongoing international clinical trials are studying these uses and follow-up data are accumulating on completed studies.

Targeted Intraoperative Radiotherapy Tumour Bed Boost during Breast-Conserving Surgery after Neoadjuvant Chemotherapy - a Subgroup Analysis of Hormone Receptor-Positive HER2-Negative Breast Cancer

Introduction

In a previous study our group showed a beneficial effect of targeted intraoperative radiotherapy (TARGIT-IORT) as an intraoperative boost on overall survival after neoadjuvant chemotherapy (NACT) compared to an external boost (EBRT). In this study we present the results of a detailed subgroup analysis of the hormone receptor (HR)-positive HER2-negative patients.

Methods

In this cohort study involving 46 patients with HR-positive HER2-negative breast cancer after NACT, we compared the outcomes of 21 patients who received an IORT boost to those of 25 patients treated with an EBRT boost. All patients received whole breast radiotherapy.

Results

Median follow-up was 49 months. Whereas disease-free-survival and breast cancer-specific mortality were not significantly different between the groups, the 5-year Kaplan-Meier estimate of overall mortality was significantly lower by 21% with IORT, p = 0.028. Non-breast cancer-specific mortality was significantly lower by 16% with IORT, p = 0.047.

Conclusion

Although our results have to be interpreted with caution, we have shown that the improved overall survival demonstrated previously could be reproduced in the HR-positive HER2-negative subgroup. These data give further support to the inclusion of such patients in the TARGIT-B (Boost) randomised trial that is testing whether IORT boost is superior to EBRT boost.

HnRNPK/miR-223/FBXW7 feedback cascade promotes pancreatic cancer cell growth and invasion

Several studies have identified miR-223 critically involved in various types of cancer, including pancreatic ductal adenocarcinoma (PDAC). However, its action and regulatory mechanisms in PDAC remains largely unclear. In this study, we found that the expression levels of miR-223 were increased in clinical samples with PDAC (81.6%). The upregulation of miR-223 increases the proliferation, migration, and invasive abilities of PDAC cells in vitro and in vivo. Mechanistically, miR-223 directly targeted FBXW7 and overexpression of FBXW7 reverted miR-223- induced drastic proliferation in PDAC cells. Interestingly, miR-223 promoter was found to form a coprecipitable complex with hnRNPK, and siRNA knockdown of hnRNPK in PDAC cells reduced the levels of miR-223. These results show that hnRNPK is a cellular protein that binds and affects the accumulation of miR-223 in PDAC. Furthermore, FBXW7 interacts with hnRNPK and promotes its degradation, which requires phosphorylation of hnRNPK at threonine 1695 by GSK3. Consistently, we observed an inverse expression pattern between FBXW7 and miR-223, whereas a positive expression pattern between miR-223 and hnRNPK was found in human PDAC tissues. These data unveiled an important new miR-223/FBXW7/HnRNPK feedback cascade in human PDAC.

Common biological phenotypes characterize the acquisition of platinum-resistance in epithelial ovarian cancer cells

Standard of care for Epithelial Ovarian Cancer (EOC) patients relies on platinum-based therapy. However, acquired resistance to platinum occurs frequently and predicts poor prognosis. To understand the mechanisms underlying acquired platinum-resistance, we have generated and characterized three platinum-resistant isogenic EOC cell lines. Resistant cells showed 3-to 5- folds increase in platinum IC50. Cross-resistance to other chemotherapeutic agents commonly used in the treatment of EOC patients was variable and dependent on the cell line utilized. Gene expression profiling (GEP) of coding and non-coding RNAs failed to identify a common signature that could collectively explain the mechanism of resistance. However, we observed that all resistant cell lines displayed a decreased level of DNA platination and a faster repair of damaged DNA. Furthermore, all platinum resistant cell lines displayed a change in their morphology and a higher ability to grown on mesothelium. Overall, we have established and characterized three new models of platinum-resistant EOC cell lines that could be exploited to further dissect the molecular mechanisms underlying acquired resistance to platinum. Our work also suggests that GEP studies alone, at least when performed under basal culture condition, do not represent the optimal way to identify molecular alterations linked to DNA repair pathway defects.

An Integrated Approach Identifies Mediators of Local Recurrence in Head and Neck Squamous Carcinoma

Purpose: Head and neck squamous cell carcinomas (HNSCCs) cause more than 300,000 deaths worldwide each year. Locoregional and distant recurrences represent worse prognostic events and accepted surrogate markers of patients' overall survival. No valid biomarker and salvage therapy exist to identify and treat patients at high-risk of recurrence. We aimed to verify if selected miRNAs could be used as biomarkers of recurrence in HNSCC.Experimental Design: A NanoString array was used to identify miRNAs associated with locoregional recurrence in 44 patients with HNSCC. Bioinformatic approaches validated the signature and identified potential miRNA targets. Validation experiments were performed using an independent cohort of primary HNSCC samples and a panel of HNSCC cell lines. In vivo experiments validated the in vitro results.Results: Our data identified a four-miRNA signature that classified HNSCC patients at high- or low-risk of recurrence. These miRNAs collectively impinge on the epithelial-mesenchymal transition process. In silico and wet lab approaches showed that miR-9, expressed at high levels in recurrent HNSCC, targets SASH1 and KRT13, whereas miR-1, miR-133, and miR-150, expressed at low levels in recurrent HNSCC, collectively target SP1 and TGFβ pathways. A six-gene signature comprising these targets identified patients at high risk of recurrences, as well. Combined pharmacological inhibition of SP1 and TGFβ pathways induced HNSCC cell death and, when timely administered, prevented recurrence formation in a preclinical model of HNSCC recurrence.Conclusions: By integrating different experimental approaches and competences, we identified critical mediators of recurrence formation in HNSCC that may merit to be considered for future clinical development. Clin Cancer Res; 23(14); 3769-80. ©2017 AACR.