The accuracy of MRI in detecting pathological complete response following neoadjuvant chemotherapy in different breast cancer subtypes.

BACKGROUND: Pathological complete response (pCR) following neo-adjuvant chemotherapy (NACT) for breast cancer is associated with improved disease-free and overall survival in certain breast cancer subtypes. Magnetic Resonance Imaging (MRI) is increasingly used as standard to assess treatment response in patients receiving NACT. The aim of this study was to determine the clinical utility of MRI in accurately predicting pCR post-NACT. METHODS: A single-centre, retrospective study was conducted in breast cancer patients, who received NACT between 2013 and 2020. Patients who had an MRI before and after NACT were included. Pathological and MRI radiological response rates to NACT were analyzed and MRI accuracy assessed in detecting pCR according to breast cancer subtype. RESULTS: One hundred and sixty-seven patients were included in the study. Forty-one of the 167 patients achieved pCR (24.6 %), with the highest proportion in HR- HER2+ subgroup (58.3 %), followed by triple negative breast cancer (TNBC) (35 %). Only 22.2 % and 10.5 % of patients with HR + HER2+ and HR + HER2-respectively achieved pCR. The overall accuracy of MRI in predicting pCR after NACT was 77.3 %. The greatest accuracy was in TNBC (87.5 %) with a specificity and positive predictive value (PPV) of 100 % and the highest number of correctly diagnosed complete responses (14 of 40). MRI was less accurate in predicting response rates in HR + HER2- (PPV 91.2 %) and HR + HER2+ groups (PPV 90.5 %). MRI performed significantly better in predicting complete response in TNBC compared to HR + HER2-subtype (p = 0.0057). CONCLUSION: MRI is a clinically useful adjunct in assessing pCR following NACT and appears to predict pathological response more accurately in TNBC compared to HR + HER2-breast cancer subtypes. This has significant clinical implications in terms of surgical planning, adjuvant treatment options and prognosis.

Shaping of the abdominal flap in breast reconstruction: The coning technique in muscle sparing TRAM.

In the setting of autologous breast reconstruction, achieving an aesthetic outcome through shaping of the flap is of the upmost importance. We describe the abdominal flap folding technique of 'coning' and the indications. We define 'coning' as the technique of folding the abdominal flap in a circular fashion to create a conical breast mound, with the line of fusion forming a pillar of tissue for structural integrity. A retrospective study of 34 patients undergoing unilateral muscle-sparing TRAM flap was performed. Of these patients, the majority (79.4%) underwent immediate reconstruction, with the thoracodorsal vessels largely acting as the recipients (94.1%). Three (8.8%) patients were noted to have a contour defect secondary to incomplete folding of the flap. Two (5.9%) patients had partial skin envelope necrosis. One patient had 50% flap loss, requiring return to theatre for excision. In conclusion, coning was used exclusively in the muscle-sparing TRAM flap. This cuff of muscle protected the pedicle during folding through cushioning the perforators at their most vulnerable points. This technique allowed for muscle cuff harvest whilst minimising anterior sheath sacrifice. Coning achieved long-term maintenance of shape, volume and projection.

No-drain Technique in Abdominal Closure for Breast Reconstruction: Lower Complication Rate, Shorter Hospitalization Stay.

BACKGROUND: Progressive tension suture (PTS) technique in cosmetic abdominoplasty is safe in terms of seroma rates. This was extrapolated to deep inferior epigastric perforator (DIEP) flap donor site closure. No study to our knowledge has analyzed the PTS technique alone without drains in transverse rectus abdominis musculocutaneous (TRAM) flap donor sites. We aim to show that no-drain closure has similar complication rates and this may be applied to TRAM flaps safely even though they have higher drain output. METHODS: A single-center, single-surgeon retrospective study was performed over 4 years. Patients undergoing breast reconstruction with an abdominal flap were included. Data collected included patient's demographics, type of flap, usage of drains or PTS technique, drain output, date of fitness for discharge, date of discharge, and seroma rates. The outcomes studied were drain volumes, seroma rates, and duration of hospital stay. RESULTS: Fifty patients were recruited. The first 25 patients (13 DIEP and 12 TRAM) underwent conventional closure. The subsequent 25 patients (17 DIEP and 8 TRAM) underwent PTS technique. TRAM flaps had higher drain volume (785.6 mL) compared to DIEP flaps (366.2 mL) (P = 0.047). No patients developed a seroma. Patients who underwent the PTS technique had lower abdominal-specific complications (P = 0.021). Patients without drains were discharged faster at 5.4 versus 8.2 days (P ≤ 0.001). CONCLUSIONS: Patients who underwent the PTS technique had lower complication rates, faster time to fitness for discharge and shorter hospitalization stay. The PTS technique may be applied to TRAM flaps safely.

A Rare Case of Persistent Unilateral Gestational Gigantomastia.

A 34-year-old para 2 + 0 Indonesian woman presented with persistent right-sided gestational gigantomastia some 24 months following delivery. This was severely debilitating her activities of daily living, including caring for her children. On examination, she was found to have extreme hypertrophy of her right breast, which was nodular throughout on palpation. Biochemical investigations were unremarkable and revealed no obvious etiology. Magnetic resonance imaging identified grossly enlarged right breast tissue with prominent vessels. Given the minimal involution of her breast over the 24 months postpartum, she elected for a breast reduction with free nipple grafting following appropriate counseling. This was performed through excision of breast parenchyma preserving superior-medial tissue, followed by a free nipple graft.

Activation of AMP-activated protein kinase rapidly suppresses multiple pro-inflammatory pathways in adipocytes including IL-1 receptor-associated kinase-4 phosphorylation.

Inflammation of adipose tissue in obesity is associated with increased IL-1ß, IL-6 and TNF-α secretion and proposed to contribute to insulin resistance. AMP-activated protein kinase (AMPK) regulates nutrient metabolism and is reported to have anti-inflammatory actions in adipose tissue, yet the mechanisms underlying this remain poorly characterised. The effect of AMPK activation on cytokine-stimulated proinflammatory signalling was therefore assessed in cultured adipocytes. AMPK activation inhibited IL-1ß-stimulated CXCL10 secretion, associated with reduced interleukin-1 receptor associated kinase-4 (IRAK4) phosphorylation and downregulated MKK4/JNK and IKK/IκB/NFκB signalling. AMPK activation inhibited TNF-α-stimulated IKK/IκB/NFκB signalling but had no effect on JNK phosphorylation. The JAK/STAT3 pathway was also suppressed by AMPK after IL-6 stimulation and during adipogenesis. Adipose tissue from AMPKα1-/- mice exhibited increased JNK and STAT3 phosphorylation, supporting suppression of these distinct proinflammatory pathways by AMPK in vivo. The inhibition of multiple pro-inflammatory signalling pathways by AMPK may underlie the reported beneficial effects of AMPK activation in adipose tissue.

Phosphorylation of Janus kinase 1 (JAK1) by AMP-activated protein kinase (AMPK) links energy sensing to anti-inflammatory signaling.

Adenosine 5'-monophosphate-activated protein kinase (AMPK) is a pivotal regulator of metabolism at cellular and organismal levels. AMPK also suppresses inflammation. We found that pharmacological activation of AMPK rapidly inhibited the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in various cells. In vitro kinase assays revealed that AMPK directly phosphorylated two residues (Ser515 and Ser518) within the Src homology 2 domain of JAK1. Activation of AMPK enhanced the interaction between JAK1 and 14-3-3 proteins in cultured vascular endothelial cells and fibroblasts, an effect that required the presence of Ser515 and Ser518 and was abolished in cells lacking AMPK catalytic subunits. Mutation of Ser515 and Ser518 abolished AMPK-mediated inhibition of JAK-STAT signaling stimulated by either the sIL-6Rα/IL-6 complex or the expression of a constitutively active V658F-mutant JAK1 in human fibrosarcoma cells. Clinically used AMPK activators metformin and salicylate enhanced the inhibitory phosphorylation of endogenous JAK1 and inhibited STAT3 phosphorylation in primary vascular endothelial cells. Therefore, our findings reveal a mechanism by which JAK1 function and inflammatory signaling may be suppressed in response to metabolic stress and provide a mechanistic rationale for the investigation of AMPK activators in a range of diseases associated with enhanced activation of the JAK-STAT pathway.

Colo-colic intussusception secondary to lipomatous polyp in an adult.

A woman in her early 50s presented with a 2-week history of gradually worsening colicky abdominal pain with associated vomiting, loose stools and reduced appetite. There was no malaena or perrectal bleeding. On examination, there was tenderness in the epigastric region with an associated palpable fullness. Subsequent imaging revealed a substantial colo-colic intussusception with the lead point being a lipoma of the ascending colon. Subsequent colonic resection was undertaken with histology confirming a lipomatous polyp.

Priming of signal transducer and activator of transcription proteins for cytokine-triggered polyubiquitylation and degradation by the A 2A adenosine receptor.

Here we demonstrate that overexpression of the human A(2A) adenosine receptor (A(2A)AR) in vascular endothelial cells confers an ability of interferon-alpha and a soluble IL-6 receptor/IL-6 (sIL-6R alpha/IL-6) trans-signaling complex to trigger the down-regulation of signal transducer and activator of transcription (STAT) proteins. It is noteworthy that STAT down-regulation could be reversed by coincubation with A(2A)AR-selective inverse agonist 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM241385) but not adenosine deaminase, suggesting that constitutive activation of the receptor was responsible for the effect. Moreover, STAT down-regulation was selectively abolished by proteasome inhibitor N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132), whereas lysosome inhibitor chloroquine was without effect. Down-regulation required Janus kinase (JAK) activity and a Tyr705-->Phe-mutated STAT3 was resistant to the phenomenon, suggesting that JAK-mediated phosphorylation of this residue is required. Consistent with this hypothesis, treatment of A(2A)AR-overexpressing cells with sIL-6R alpha/IL-6 triggered the accumulation of polyubiquitylated wild-type but not Tyr705-->Phe-mutated STAT3. Support for a functional role of this process was provided by the observation that A(2A)AR overexpression attenuated the JAK/STAT-dependent up-regulation of vascular endothelial growth factor receptor-2 by sIL-6R alpha/IL-6. Consistent with a role for endogenous A(2A)ARs in regulating STAT protein levels, prolonged exposure of endogenous A(2A)ARs in endothelial cells with ZM241385 in vitro triggered the up-regulation of STAT3, whereas deletion of the A(2A)AR in vivo potentiated STAT1 expression and phosphorylation. Together, these experiments support a model whereby the A(2A)AR can prime JAK-phosphorylated STATs for polyubiquitylation and proteasomal degradation and represents a new mechanism by which an anti-inflammatory seven-transmembrane receptor can negatively regulate JAK/STAT signaling.

Selective inhibition of cytokine-activated extracellular signal-regulated kinase by cyclic AMP via Epac1-dependent induction of suppressor of cytokine signalling-3.

Here we demonstrate that elevation of cyclic AMP (cAMP) levels in human umbilical vein endothelial cells (HUVECs) specifically attenuates ERK1,2 activation in response to either leptin or a soluble interleukin IL-6 receptor-alpha/IL-6 (sIL-6R alpha/IL-6) trans-signalling complex but not protein kinase C activator phorbol 12-myristate 13-acetate. The inhibitory effects of cAMP on sIL-6R alpha/IL-6-stimulated phosphorylation of ERK1,2 and STAT3 were abolished by either short interfering (si) RNA-mediated knockdown or genetic ablation of suppressor of cytokine signalling-3 (SOCS-3). The inhibitory effect of cAMP could not be reversed by inhibition of cAMP-dependent protein kinase (PKA) but was blocked by depletion of the alternative intracellular cAMP sensor exchange protein activated by cAMP 1 (Epac1), which is also required to observe SOCS-3 accumulation in response to cAMP. Interestingly, the ability of cAMP elevation to inhibit IL-6 signalling was blocked by ERK inhibition. Consistent with this observation, cAMP elevation in HUVECs produced a transient yet robust activation of ERK, and subsequent phosphorylation of transcription factor C/EBP beta, both of which were resistant to PKA inhibition. However, siRNA depletion and immunoblotting experiments revealed that neither Epac1 nor Epac2 contributed to the PKA-independent activation of ERK1,2 observed following cAMP elevation. Together, these observations suggest that while SOCS-3 induction and subsequent inhibition of cytokine-mediated phosphorylation of ERK1,2 and STAT3 in response to cAMP require Epac1 and a transient PKA-independent activation of the ERK pathway, these two events are controlled by distinct mechanisms. In addition, it reveals a novel Epac-dependent mechanism by which cAMP can specifically inhibit ERK in response to cytokine receptor activation.

Exchange protein activated by cyclic AMP (Epac)-mediated induction of suppressor of cytokine signaling 3 (SOCS-3) in vascular endothelial cells.

Here, we demonstrate that elevation of intracellular cyclic AMP (cAMP) in vascular endothelial cells (ECs) by either a direct activator of adenylyl cyclase or endogenous cAMP-mobilizing G protein-coupled receptors inhibited the tyrosine phosphorylation of STAT proteins by an interleukin 6 (IL-6) receptor trans-signaling complex (soluble IL-6Ralpha/IL-6). This was associated with the induction of suppressor of cytokine signaling 3 (SOCS-3), a bona fide inhibitor in vivo of gp130, the signal-transducing component of the IL-6 receptor complex. Attenuation of SOCS-3 induction in either ECs or SOCS-3-null murine embryonic fibroblasts abolished the inhibitory effect of cAMP, whereas inhibition of SHP-2, another negative regulator of gp130, was without effect. Interestingly, the inhibition of STAT phosphorylation and SOCS-3 induction did not require cAMP-dependent protein kinase activity but could be recapitulated upon selective activation of the alternative cAMP sensor Epac, a guanine nucleotide exchange factor for Rap1. Consistent with this hypothesis, small interfering RNA-mediated knockdown of Epac1 was sufficient to attenuate both cAMP-mediated SOCS-3 induction and inhibition of STAT phosphorylation, suggesting that Epac activation is both necessary and sufficient to observe these effects. Together, these data argue for the existence of a novel cAMP/Epac/Rap1/SOCS-3 pathway for limiting IL-6 receptor signaling in ECs and illuminate a new mechanism by which cAMP may mediate its potent anti-inflammatory effects.

Phosphorylation-independent internalisation and desensitisation of the human sphingosine-1-phosphate receptor S1P3.

Here we demonstrate that phosphorylation of the sphingosine-1-phosphate (S1P) receptor S1P(3) is increased specifically in response to S1P. Truncation of the receptor's carboxyl-terminal domain revealed that the presence of a serine-rich stretch of residues between Leu332 and Val352 was essential to observe this effect. Although agonist-occupied wild-type (WT) S1P(3) could be phosphorylated in vitro by G-protein-coupled receptor kinase 2 (GRK2), a role of S1P(3) phosphorylation in controlling S1P(3)-G(q/11) coupling was excluded since A) a phosphorylation-resistant S1P(3) mutant desensitised in a manner indistinguishable from the WT receptor and was phosphorylated to a greater extent than the WT receptor by GRK2 in vitro, and B) co-expression with GRK2 or GRK3 failed to potentiate S1P(3) phosphorylation. S1P(3) phosphorylation was also not required for receptor sequestration away from the cell surface. Together, these data suggest that S1P(3) function is not subject to conventional regulation by GRK phosphorylation and that novel aspects of S1P(3) function distinct from classical G-protein coupling and receptor internalisation may be controlled its carboxyl-terminal domain.