Oligometastatic carcinoma prostate - An overview of the last decade.

Introduction: Oligometastatic prostate cancer (OMPC) has gained profound interest lately due to its different tumor biology and our ability to use multimodality therapy for cure or prolonged survival. Selecting the appropriate patient for treatment has become the aim of treating urologists, medical oncologists, and radiation oncologists. Through this review, we try to highlight the management of OMPC in light of recent literature. Methods: Literature search was performed on Pubmed, Scopus and Embase using keywords "Oligometastatic", " Prostate Cancer" using operators such as "And" & "Or". Relevant articles were screened and all the latest articles on this emerging entity were included in this review. Results: All trials relevant to oligometastatic prostate cancer defining the role of surgery, radiotherapy and systemic therapy were included and appropriate inferences were drawn. Relevant studies were compiled in tabular form for this article. Conclusion: The current standard of care of management for OMPC remains systemic therapy on the lines of hormone-sensitive metastatic prostate cancer. The evolving role of surgery, and radiotherapy along with systemic therapy is highlighted in this article.

Stage Migration in Renal Malignancies in COVID Era: A Single-Center Analysis.

The COVID-19 disease, caused by SARS-CoV-2 virus, attained the status of a pandemic by March 2020. There was apprehension among patients suffering from renal malignancies about balancing cancer treatment and preventing COVID-19 infection transmission. We analyzed 184 patients with renal malignancies retrospectively, who presented to our institute over 2 years: 91 patients of renal malignancies in pre-COVID era (March 2019-Feb 2020) and 93 patients in COVID era (March 2020-Feb 2021). The parameters analyzed were age, tumor size, clinical presentation, clinical stage, pathological stage, nuclear grade, and presence of metastasis. Level of significance was kept at 95%, and p value <0.05 was considered significant. The age of patients was comparable in both groups (p: 0.381). Clinical presentation was also similar in both groups whereas there were more cases diagnosed during routine evaluation in pre-COVID era (p: 0.022). Tumor size was 5.84 ± 3.03cm vs. 7.10±3.83cm (p: 0.017) in pre-COVID vs. COVID era, respectively. Patients in COVID era had significantly higher clinical stage (p = 0.041), pathological stage (p =0.027), nuclear grade (p = 0.007), and presence of metastasis (p = 0.005) as compared to pre-COVID era. Patients, who underwent Nephron-sparing surgery, also had higher pathological stage in COVID era. COVID overshadowed the management of renal malignancies. There was a clear shift and stage migration in patients of renal malignancies in COVID era as compared to pre-COVID era, probably because of less routine health check-ups and patients deferring hospital visits due to fear of contracting COVID infection.

Outcomes of Hem-o-Lok clip migration at vesico-urethral anastomotic site post-robotic-assisted laparoscopic radical prostatectomy: a single centre experience.

BACKGROUND: Robotic-assisted laparoscopic prostatectomy (RALP) is the most preferred intervention for the management of prostatic malignancy worldwide. Hem-o-Lok clips (HOLC) are widely used for haemostasis and lateral pedicle ligation. These clips are prone to migrate and lodge at the anastomotic junction as well as inside the bladder causing lower urinary tract symptoms (LUTS) secondary to bladder neck contracture (BNC) or bladder calculi. The objective of this study is to describe the incidence, clinical presentation, management, and outcome of HOLC migration. METHODOLOGY: Retrospective analysis of the database of Post RALP patients who developed LUTS secondary to HOLC migration was done. Cystoscopy findings, number of procedures required, number of HOLC removed intra-operatively, and follow-up of the patients was reviewed. RESULTS: The incidence of HOLC migration requiring intervention was 1.78% (9/505). The mean age of the patient, BMI, Pre-operative Serum PSA were 62.8 years, 27.8 kg/m2, and 9.8 ng/mL, respectively. The mean duration of appearance of symptoms due to HOLC migration was 9 months. Two patients presented with Haematuria and 7 presented with LUTS. Seven patients required a single intervention while 2 required up to 6 procedures for recurrent symptoms secondary to recurrent HOLC migration. CONCLUSION: HOLC use in RALP may present with migration and associated complications. HOLC migration is associated with severe BNC and may require multiple endoscopic interventions. Severe dysuria and LUTS not responding to medical management should be treated using an algorithmic approach and there should be a low threshold for performing cystoscopy and intervention in these cases to improve outcomes.

Outcome of post-COVID-19 fungal pyelonephritis: A single Indian tertiary center experience.

Introduction: COVID-19 pandemic is associated with secondary opportunistic fungal infections. These have an aggressive course with a high mortality rate. We present our experience of seven cases of post-COVID-19 fungal pyelonephritis. Methods: An observational study over a period of 8 months of May to December 2021 was carried out at our tertiary care hospital, including all patients with features of fungal pyelonephritis in post-COVID-19 setting. The patient demographics, details of previous COVID-19 infection, details of present admission and management were collected. The endpoints were either discharge from the hospital or death. Results: Seven patients were included. Mean age of presentation was 42 years (range: 20-63 years, standard deviation ± 14.2). Male-to-female ratio was 6:1. One patient was diabetic. Two patients were asymptomatic, one had mild infection, and four patients had severe COVID-19 infection as per National Institute of Health criteria. In the present admission, all patients had symptomatic pyelonephritis with laboratory parameters showing elevated D dimer, C reactive protein, and total leukocyte counts. In all seven patients, ultrasound of kidney ureter bladder region showed bulky kidney, color Doppler showed main renal arterial thrombosis in two patients, segmental arterial thrombosis in another patient. Computed tomography scan was suggestive of changes of pyelonephritis in all patients with multiple renal hypodense areas. All patients required nephrectomy with biopsy suggestive of changes of necrotizing fungal inflammation. Three patients expired. Conclusion: Management of post-COVID-19 fungal pyelonephritis should be aggressive and suspicious laboratory and imaging findings should be treated by early nephrectomy.

Initial experience with slimmest single-use flexible ureteroscope Uscope PU3033A (PUSEN™) in retrograde intrarenal surgery and its comparison with Uscope PU3022a: a single-center prospective study.

PURPOSE: Single-use disposable digital flexible ureterorenoscope has become an attractive option to reusable scope with many advantages. Currently available single-use digital fURS have outer shaft diameter above 9 Fr which requires large access sheath insertion and sometimes double J stent placement. Recently, 7.5 Fr single-use digital fURS is introduced in market by Pusen. Objective of this study is to compare two Pusen single-use scopes in the clinical setting: 7.5 Fr Uscope PU3033A and 9.5 Fr Uscope PU3022A. METHODS: 30 patients, having renal stones < 2 cm, planned for RIRS were prospectively randomized to two groups: group 1 had 15 patients in which 7.5 Fr Uscope PU3033A and group 2 had 15 patients in which 9.5 Fr Uscope PU3022A was used. The various pre-operative, intra-operative, and post-operative parameters at 1 month along with complications were evaluated for both the scopes by a single surgical team. RESULTS: Pre-operative parameters including stone characteristics were comparable in both the groups. Three patients in group 2 needed ureteric dilatation prior to 11/13 access sheath insertion, while 10/12 Fr access sheath was placed in all patients in group 1 without manipulation (p = 0.06). Intra-operative vision was comparable in both scopes with an empty working channel and with laser. Hazy vision while lasing in two and one patient in group 1 and group 2, respectively (p = 0.54). In group 1, one had fever and UTI, while in group 2, one had fever post-operatively. CONCLUSION: 7.5 Fr Uscope PU3033A could be introduced with smaller access sheath. The vision, deflection, maneuverability is comparable to 9.5 Fr Uscope PU3022a.

Myelolipoma of Kidney: A Rare Extra-Adrenal Tumor in an Unusual Site.

Myelolipoma of the kidney is a very rare benign disease which is composed of mature adipose tissue admixed with mature hematopoietic elements in varying proportions. The most common location of myelolipoma is in the adrenal glands, but extra-adrenal myelolipomas in other locations such as the retroperitoneum, presacral region, pelvis, and mediastinum has also been reported. In this case report, we present a case of huge extra-adrenal myelolipoma in renal parenchyma which is rare site for its origin. We report a case of extra-adrenal myelolipoma occurring in the left kidney of a 46-year-old Indian man. We describe the radiological and clinicopathologic features of this unusual tumor with a review of the literature. This case is noteworthy because the tumor was very enlarged and its site was unusual. It is generally impossible to distinguish extra-adrenal myelolipoma from other retroperitoneal tumors by radiological imaging given the rarity of tumor more cases need to be reported to elucidate its biological behavior.

A clinical experience of thulium fibre laser in miniperc to dust with suction: a new horizon.

PURPOSE: To report safety and efficacy of mini-PCNL with suction attached to sheath combined with high-power Thulium Fibre laser (TFL). The secondary aim was to evaluate optimal laser settings for maximum stone dusting. MATERIALS AND METHODS: Prospective, single arm study was conducted from June 2019-December 2019 using miniPCNL with suction and TFL in 54 patients with renal stones < 3 cm. Stone fragments for each laser setting were independently retrieved and segregated according to size(< 1 mm,1-3 mm, > 3 mm) and weighed. Xray/CT scan imaging was performed in all patients within 48 h and 30 days to assess stone clearance. Optimal laser settings were evaluated for maximum dusting. RESULTS: Mean stone size was 18.32 ± 6.37 mm, volume was 2337.75 ± 1996.84mm3 and stone density was 1300.55 ± 435.32 HU. Total operative time was 39.85 ± 20.52 min, laser time was 10.08 ± 7.41 min and stone fragmentation rate was 5.02 ± 3.93 mm3/s. The procedure was completely tubeless in 37.04%, nephrostomy tube in 37.04% and DJ stent placed in 25.92%. Postoperatively, three patients had urinary infection (Clavien 2). Complete stone clearance at 48 h was achieved in 35 (64.8%) cases. 19 patients (35.2%) who had residual fragments at 48 h, had 100% clearance at one month on CT/Xray KUB. CONCLUSIONS: MiniPCNL using a nephrostomy sheath with suction along with high power Thulium Fibre Laser is safe and effective modality for lithotripsy. An initial laser setting of 0.2 J and 125-200 Hz was optimal for maximum dusting and simultaneous aspiration. Randomized comparative studies with other energy sources are being considered.

Validity of a Novel Chicken and Porcine Model for Laparoscopic Neobladder Reconstruction.

Introduction: Simulation-based training in laparoscopic urology is essential, as these surgeries require a skill set different from routine urologic procedures. We aim to describe and validate the chicken and porcine intestine model for laparoscopic neobladder reconstruction. Materials and Methods: Prospective observational study was conducted at our institute. Twenty novice and 20 trained laparoscopic surgeons were included in the study. The relevant chicken anatomy and surgical steps were described to all the surgeons. The surgeons were asked to fill a nine-point questionnaire after completing the exercise comprising bowel organization, ability to do urethroneovesical anastomosis, suturing time, suturing similarity, quality of suturing, tissue feel, integrity of anastomosis, realism, and usefulness of model after finishing the procedure, and score it on a scale of 1-5. Time taken to perform the entire exercise was noted in addition. An independent expert observer retrospectively rated the urethroneovesical anastomosis on a scale of 1-5. Results: All the participants in the study gave a mean score of 3.5 or more to all the questions asked in the questionnaire. Both the groups rated the usefulness of the model highly with a mean score of 4.6 and 4.45, respectively. The mean score of the questionnaire was 35.9 and 36, respectively, for both the groups. The quality of urethroneovesical anastomosis as observed by an expert was better in the expert group (p = 0.001). Conclusion: The chicken and porcine model for laparoscopic neobladder reconstruction is a useful and effective training tool. This model has face, content, and construct validity to be used as a teaching and training tool in laparoscopic urology.

A Single-Center Prospective Comparative Study of Two Single-Use Flexible Ureteroscopes: LithoVue (Boston Scientific, USA) and Uscope PU3022a (Zhuhai Pusen, China).

Introduction and Objective: Single-use flexible ureteroscopes have the benefit of decreasing infection transmission, avoiding sterilization need, and no maintenance cost. Primary objective was to compare in vivo performance and surgical outcomes with two single-use ureteroscopes: LithoVue (Boston Scientific, USA) and Uscope PU3022a (Zhuhai Pusen, China) with secondary objective being to compare in vivo vision by independent endourologist blinded to ureteroscope manufacturer. Materials and Methods: Fifty patients undergoing retrograde intrarenal surgery with <2 cm renal stones were prospectively allocated: Group 1 (25 patients) for LithoVue and group 2 (25 patients) for Uscope. Pre-, intra-, and postoperative parameters were evaluated. Vision of both ureteroscopes with and without accessory was evaluated by an independent endourologist, blinded to the make of the ureteroscope. Stone clearance was assessed with kidney, ureter, and bladder radiograph (KUB) and ultrasonography KUB at 1 month. Student's t-test for quantitative and chi-square for categorical data was used. Results: Pre- and intraoperative parameters such as need for ureteral dilatation (p > 0.05), ureteral access-sheath size (p = 0.78), accessibility to pelvicaliceal system (p > 0.05), and maneuverability (p > 0.05) were comparable in both groups. Lower-pole access was possible in all cases of LithoVue and slightly difficult in three cases of Uscope (p > 0.5). Intraoperative vision was hazy in four cases of LithoVue and eight cases of Uscope (p = 0.32) during lasing along with three cases of Uscope with accessory (p = 0.24). Blinded endourologist reported more cases of hazy vision with or without accessory or lasing in Uscope arm (p > 0.05). One device had malfunction in LithoVue arm. Complete stone clearance was achieved in all cases at 1 month. Conclusions: We conclude that performance of these two single-use ureteroscopes, LithoVue and Uscope, is comparable in clinical settings with similar clinical outcomes and complications.

Migration of Hem-O-Lok in Pelvicaliceal System Mimicking Renal Calculus Following Robotic Nephron-Sparing Surgery: A Case Report with Review of Literature.

Background: Migration of Hem-O-Lok clips in pelvicaliceal system after nephron-sparing surgery (NSS) is rare. We present a rare case of clip migration 8 years after robotic NSS. Case Presentation: A 61-year-old female presented with right flank pain and fever 8 years after robotic NSS for clear cell carcinoma. She was reported to have an 11 mm right renal calculus (570 HU) on CT scan. She underwent flexible ureteroscopy that revealed three Hem-O-Lok clips with encrustations. We removed the clips after laser lithotripsy of the encrusted clips. She is now asymptomatic on follow-up. Conclusion: The possibility of intrarenal migration of Hem-O-Lok clips should be kept as differential diagnosis for patients presenting as renal calculus postminimal access NSS. They could act as nidus for stone formation, leading to recurrent urinary infection. Excessive tension on renorrhaphy sutures should be avoided to prevent migration of clips. The underrunning of any clip in the renal bed during reconstruction should be the standard of care.

Pericardial sarcoidosis presenting as PUO diagnosed on FDG PET CT scan.

Pyrexia of unknown origin (PUO) is a common problem in day-to-day practice. FDG PET CT is an established investigation that aids in identifying the cause of PUO. Due to its high sensitivity PET detects an occult hypermetabolic focus in the body where CT helps in anatomical localization, vascularity, enhancement characteristics of the lesion detected on PET. It helps to differentiate benign versus malignant cause and target biopsy. Tuberculosis, lymphoma, pyelonephritis, thyroiditis appear hypermetabolic on FDG PET CT. Pericardial sarcoidosis is rare and not reported in literature as a cause of PUO. Presented here is a case of PUO secondary to pericardial granulomatosis diagnosed on PET CT. Cardiac MRI also helps in better tissue characterization and associated myocardial involvement of sarcoidosis. Histology confirmed the diagnosis of pericardial sarcoidosis in this case.

Localization of acute pyelonephritis in pyrexia of unknown origin using FDG PET/CT.

OBJECTIVES: Acute pyelonephritis presents with high-grade fever, dysuria, flank pain, leukocytosis, and microscopic hematuria. Urine culture aids in the diagnosis of this infection. It can be complicated or uncomplicated. Complicated pyelonephritis includes uncontrolled diabetes, transplant, pregnancy, acute or chronic renal failure, structural abnormality of the urinary tract, immunocompromised state, and hospital-acquired infections. Gram-negative bacteria commonly involved are Escherichia, Klebsiella, Proteus, and Enterobacter. The FDG PET/CT helps detect occult causes of fever, such as skeletal tuberculosis, thyroiditis, and lymphoma, when other investigations are inconclusive. We present three cases of pyrexia of unknown origin (PUO) in whom FDG PET/CT helped localize the focus of infection in the kidneys. METHODS: The 18F-FDG PET/CT was performed on all three cases and images were acquired using the Biograph Horizon PET/CT system. RESULTS: A cortical-based focus of FDG uptake was localized in the kidneys. The focus of abnormality was persistent following diuretic administration at 1-hour delayed regional image. Two cases had supportive evidence of pyelonephritis on DMSA scan. One case also had frank pus drained after DJ stenting of the affected side. All of them responded to treatment. CONCLUSION: Physiologic excretion of FDG in the urinary tract may interfere with the detection of the focus of infection in the kidneys on FDG PET/CT. However, occult infection in the kidneys may be detected with adequate precautions, such as the use of diuretics and delayed imaging, as illustrated in this case report. Routine investigations were noncontributory in all three cases presenting with PUO. However, FDG PET provided a diagnostic clue for pyelonephritis.

A fruit-tissue (apple) based training model for transurethral resection of prostate: face, content and construct validation.

AIMS AND OBJECTIVES: To establish face, content and construct validity of an innovative fruit-tissue (apple) based transurethral resection of prostate (TURP) training model devised at our institute. METHOD AND MATERIAL: Six consultants, three fellows and 16 residents performed TURP on the new fruit-tissue (apple) based TURP model for ten minutes after watching a demo-video. The procedure was videographed. At the end, participants answered a set of questionnaires regarding their experience. The video and the apple both were examined by blinded separate assessors based on pre-decided parameters. Statistical analysis was done to find out the face, content and construct validity of the training model. RESULTS: Participants were divided into two groups, expert and novice, based TURP surgery experience. The model was positively rated (lowest median value 4) by all novice for its 'realism' and 'acceptability'. The expert group also felt that the model reproduced real TURP experience (lowest median value 4). Thus, both face and content validity were established. The expert group resected more tissue (18.3±2.5 gm vs 10.3±3.4 gm; P<0.001) with less irrigation fluid (1566.6±187.0 ml vs 2112.5±344.2 ml; P<0.001) removing more chips (39.8±6.2 vs 25.6±3.0; P<0.001) and orientated themselves faster (63.3±12.2 sec vs 90.3±12.7 sec; P<0.001). The assessors' subjective evaluation of videos and apples both favored the experts. The model can differentiate 'expert' from 'novice', thus establishing 'construct validity'. CONCLUSION: The new fruit-tissue (apple) based TURP model is a realistic and acceptable TRUP training model with proven face, content and construct validity.

Robotic-assisted kidney transplant: a single center experience with median follow-up of 2.8 years.

PURPOSE: The main aim of the paper is to report a single-centre experience with RAKT, focusing on surgical, perioperative and functional outcomes at a median follow-up of 2.8 years. METHODS: Data of 26 RAKT patients was prospectively collected from December 2014 to February 2019 with follow-up of up to 55 months. All donors were done laparoscopically. We followed Vattikuti-Medanta technique with modification of using pfannenstiel incision instead of Gelpoint and patient positioned in steep Trendelenburg position (30°) with leg split position. Hypothermia was maintained using a "modified graft hypothermia jacket". The engrafted kidney is oriented with the vessels being tagged with Prolene sutures. RESULTS: The mean BMI was 26.1 ± 4.7. The mean warm, cold and total ischemia times were 4.8 ± 1.1, 113.8 ± 20.9 and 118.7 ± 21.2 min, respectively. Mean rewarming time was 62.5 ± 10 min. The mean post-operative day (POD) 1, 3, 7, 30, 6 months, 1 year and most recent creatinine was 3.4, 2.4, 1.8, 1.4,1.2, 1.2 and 1.69 mg/dl. There was no case of delayed graft dysfunction (DGF) with graft survival of 1.8-55 months. The mean GFR at POD 1, 1 month and 1 year was 24, 53.16 and 64.6. We had two intraoperative complications-one topsy turvy graft placement with anastomosis of donor ureter to native ureter and other had to be converted to open technique after anastomosis to control graft surface bleeding. Three postoperative complications-one patient has graft pyelonephritis which was managed conservatively with antibiotics. Two patients had lymphocele. One patient was managed with just aspiration while the other required laparoscopic de-roofing of the lymphocele. The mean hospital stay was 13.5 ± 3 days. CONCLUSIONS: RAKT is feasible and safe only if performed by surgeons with appropriate background in robotic surgery and kidney transplantation after proper surgical training at experienced centres in the mid-term follow-up. Further studies need to confirm the long-term safety of RAKT.

Two South Indian Children with KCNT1-Related Malignant Migrating Focal Seizures of Infancy - Clinical Characteristics and Outcome of Targeted Treatment with Quinidine.

KCNT1 gene encodes a sodium-gated potassium channel subunit that plays an important role in regulating excitability in neurons. Quinidine is a partial antagonist of this channel. We report the clinical characteristics of two south Indian children with KCNT1-related epileptic encephalopathy. Both of them had very high seizure burden which were resistant to antiepileptic and dietary therapy. Pharmacological response to quinidine in these children is described. Case 1 had 30% reduction in seizure burden at 20 mg/kg/day and 80% reduction at 36 mg/kg/day; case 2 had 30% reduction at 20 mg/kg/day. Serial electrocardiography was used to monitor the cardiotoxicity. Serum quinidine levels were not measured due to nonavailability. A critical review on the current status of targeted treatment of KCNT1-related epileptic encephalopathies with quinidine is attempted.

False-positive FDG PET CT Scan in Vertebral Hemangioma.

FDG PET CT scan is considered to be a sensitive tool to detect skeletal metastasis in known malignancies. However, it's high sensitivity and low specificity may account for false positive diagnosis in cases of trauma, infection, inflammation and other benign conditions. Skeletal hemangioma is one of the common benign conditions which are typically ametabolic on FDG PET CT with no uptake on bone scan. However, rarely they may have atypical imaging features and appear hypermetabolic. Other imaging modalities such as MRI and CT scan have typical imaging findings for hemangioma and can be used for evaluation of focal hypermetabolic skeletal lesions. There are atypical imaging characteristics in each of these modalities. Hence when used judiciously they can complement each other and avoid a false positive test result. This case report highlights the importance of bone scan and CT scan in excluding pathological involvement of skeleton with false positive FDG PET scan result.

Comparison of contrast-enhanced voiding urosonography with voiding cystourethrography in pediatric vesicoureteral reflux.

OBJECTIVE: Voiding cystourethrography (VCUG) has been considered as the gold standard technique for the diagnosis of vesicoureteral reflux (VUR). But, it requires fluoroscopic guidance which expose children to radiation. Voiding urosonography (VUS) is technically analogous to VCUG and has the major advantage of zero radiation exposure. This study aims to determine the efficacy of contrast enhanced-VUS (ce-VUS) with respect to VCUG in diagnosing VUR. MATERIAL AND METHODS: This study involves 30 children over a period of 3 years. All patients underwent a VCUG followed by the ce-VUS on the same day. All VUS studies were done by the same sonologist in the sonography department. The images were recorded and reviewed by the same sonologist before reporting. RESULTS: The median age of the patients was 51.53 months. There were 21 males and 9 females. On VCUG, 16 patients had no reflux, and 14 patients had reflux. On ce-VUS, 14 patients had no VUR, and 16 patients had VUR. Of the total 58 kidney-ureter units (KUUs), VUR was detected in 17 KUUs on VCUG and in 21 KUUs on ce-VUS. Thus, ce-VUS detected 4 refluxing units that were not seen on VCUG. In right KUUs, ce-VUS detected VUR in 3 units where no reflux was found in VCUG. In the 28 left KUUs, 25 units on ce-VUS showed concordance with the grade of VUR as detected by VCUG; 3 were discordant. Two units on ce-VUS showed a VUR one grade higher than the corresponding grade on VCUG and in one unit it was one grade lower. Thus, in total, ce-VUS picked up 4 cases which were missed by VCUG. CONCLUSION: ce-VUS is a good imaging modality when compared to voiding cystourethrography to assess pediatric vesicoureteral reflux, in view of its superior diagnostic performance, feasibility and radiation safety for children.

Human CDK18 promotes replication stress signaling and genome stability.

Cyclin-dependent kinases (CDKs) coordinate cell cycle checkpoints with DNA repair mechanisms that together maintain genome stability. However, the myriad mechanisms that can give rise to genome instability are still to be fully elucidated. Here, we identify CDK18 (PCTAIRE 3) as a novel regulator of genome stability, and show that depletion of CDK18 causes an increase in endogenous DNA damage and chromosomal abnormalities. CDK18-depleted cells accumulate in early S-phase, exhibiting retarded replication fork kinetics and reduced ATR kinase signaling in response to replication stress. Mechanistically, CDK18 interacts with RAD9, RAD17 and TOPBP1, and CDK18-deficiency results in a decrease in both RAD17 and RAD9 chromatin retention in response to replication stress. Importantly, we demonstrate that these phenotypes are rescued by exogenous CDK18 in a kinase-dependent manner. Collectively, these data reveal a rate-limiting role for CDK18 in replication stress signalling and establish it as a novel regulator of genome integrity.

The leukemia-associated Rho guanine nucleotide exchange factor LARG is required for efficient replication stress signaling.

We previously identified and characterized TELO2 as a human protein that facilitates efficient DNA damage response (DDR) signaling. A subsequent yeast 2-hybrid screen identified LARG; Leukemia-Associated Rho Guanine Nucleotide Exchange Factor (also known as Arhgef12), as a potential novel TELO2 interactor. LARG was previously shown to interact with Pericentrin (PCNT), which, like TELO2, is required for efficient replication stress signaling. Here we confirm interactions between LARG, TELO2 and PCNT and show that a sub-set of LARG co-localizes with PCNT at the centrosome. LARG-deficient cells exhibit replication stress signaling defects as evidenced by; supernumerary centrosomes, reduced replication stress-induced γH2AX and RPA nuclear foci formation, and reduced activation of the replication stress signaling effector kinase Chk1 in response to hydroxyurea. As such, LARG-deficient cells are sensitive to replication stress-inducing agents such as hydroxyurea and mitomycin C. Conversely we also show that depletion of TELO2 and the replication stress signaling kinase ATR leads to RhoA signaling defects. These data therefore reveal a level of crosstalk between the RhoA and DDR signaling pathways. Given that mutations in both ATR and PCNT can give rise to the related primordial dwarfism disorders of Seckel Syndrome and Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) respectively, which both exhibit defects in ATR-dependent checkpoint signaling, these data also raise the possibility that mutations in LARG or disruption to RhoA signaling may be contributory factors to the etiology of a sub-set of primordial dwarfism disorders.

FANCD2 re-expression is associated with glioma grade and chemical inhibition of the Fanconi Anaemia pathway sensitises gliomas to chemotherapeutic agents.

Brain tumours kill more children and adults under 40 than any other cancer. Around half of primary brain tumours are glioblastoma multiforme (GBMs) where treatment remains a significant challenge, where survival rates have improved little over the last 40 years, thus highlighting an unmet need for the identification/development of novel therapeutic targets and agents to improve GBM treatment. Using archived and fresh glioma tissue, we show that in contrast to normal brain or benign schwannomas GBMs exhibit re-expression of FANCD2, a key protein of the Fanconi Anaemia (FA) DNA repair pathway, and possess an active FA pathway. Importantly, FANCD2 expression levels are strongly associated with tumour grade, revealing a potential exploitable therapeutic window to allow inhibition of the FA pathway in tumour cells, whilst sparing normal brain tissue. Using several small molecule inhibitors of the FA pathway in combination with isogenic FA-proficient/deficient glioma cell lines as well as primary GBM cultures, we demonstrate that inhibition of the FA pathway sensitises gliomas to the chemotherapeutic agents Temozolomide and Carmustine. Our findings therefore provide a strong rationale for the development of novel and potent inhibitors of the FA pathway to improve the treatment of GBMs, which may ultimately impact on patient outcome.