The Insulin Receptor Substrate 1 (Irs1) in Intestinal Epithelial Differentiation and in Colorectal Cancer

Colorectal cancer (CRC) is associated with lifestyle factors that affect insulin/IGF signaling, of which the insulin receptor substrate 1 (IRS1) is a key transducer. We investigated expression, localization and pathologic correlations of IRS1 in cancer-uninvolved colonic epithelium, primary CRCs with paired liver metastases and in vitro polarizing Caco2 and HT29 cells. IRS1 mRNA and protein resulted higher, relative to paired mucosa, in adenomas of familial adenomatous polyposis patients and in CRCs that overexpressed c-MYC, ß-catenin, InsRß, and IGF1R. Analysis of IRS1 immunostaining in 24 cases of primary CRC with paired colonic epithelium and hepatic metastasis showed that staining intensity was significantly higher in metastases relative to both primary CRC (P<0.01) and colonic epithelium (P<0.01). Primary and metastatic CRCs, compared to colonic epithelium, contained significantly higher numbers of IRS1-positive cells (P = 0.013 and P = 0.014, respectively). Pathologic correlations in 163 primary CRCs revealed that diffuse IRS1 staining was associated with tumors combining differentiated phenotype and aggressive markers (high Ki67, p53, and ß-catenin). In Caco 2 IRS1 and InsR were maximally expressed after polarization, while IGF1R was highest in pre-polarized cells. No nuclear IRS1 was detected, while, with polarization, phosphorylated IRS1 (pIRS1) shifted from the lateral to the apical plasma membrane and was expressed in surface cells only. In HT29, that carry mutations constitutively activating survival signaling, IRS1 and IGF1R decreased with polarization, while pIRS1 localized in nuclear spots throughout the course. Overall, these data provide evidence that IRS1 is modulated according to CRC differentiation, and support a role of IRS1 in CRC progression and liver metastatization

Neutralizing antibodies to Omicron after the fourth SARS-CoV-2 mRNA vaccine dose in immunocompromised patients highlight the need of additional boosters

IntroductionImmunocompromised patients have been shown to have an impaired immune response to COVID-19 vaccines.MethodsHere we compared the B-cell, T-cell and neutralizing antibody response to WT and Omicron BA.2 SARS-CoV-2 virus after the fourth dose of mRNA COVID-19 vaccines in patients with hematological malignancies (HM, n=71), solid tumors (ST, n=39) and immune-rheumatological (IR, n=25) diseases. The humoral and T-cell responses to SARS-CoV-2 vaccination were analyzed by quantifying the anti-RBD antibodies, their neutralization activity and the IFN-γ released after spike specific stimulation.ResultsWe show that the T-cell response is similarly boosted by the fourth dose across the different subgroups, while the antibody response is improved only in patients not receiving B-cell targeted therapies, independent on the pathology. However, 9% of patients with anti-RBD antibodies did not have neutralizing antibodies to either virus variants, while an additional 5.7% did not have neutralizing antibodies to Omicron BA.2, making these patients particularly vulnerable to SARS-CoV-2 infection. The increment of neutralizing antibodies was very similar towards Omicron BA.2 and WT virus after the third or fourth dose of vaccine, suggesting that there is no preferential skewing towards either virus variant with the booster dose. The only limited step is the amount of antibodies that are elicited after vaccination, thus increasing the probability of developing neutralizing antibodies to both variants of virus.DiscussionThese data support the recommendation of additional booster doses in frail patients to enhance the development of a B-cell response directed against Omicron and/or to enhance the T-cell response in patients treated with anti-CD20

Cholangiocarcinoma: Current opinion on clinical practice diagnostic and therapeutic algorithms. A review of the literature and a long-standing experience of a referral center

In the oncology landscape, cholangiocarcinoma is a challenging disease in terms of both diagnosis and treatment. Besides anamnesis and clinical examination, a definitive diagnosis of cholangiocarcinoma should be supported by imaging techniques (US, CT, MRI) and invasive investigations (ERC or EUS with brushing and FNA or US or CT-guided biopsy) followed by pathological confirmation. Surgery is the main curative option, so resectability of the tumour should be promptly assessed. Moreover, jaundice must be evaluated at the outset because biliary tract decompression with drainage and stent placement may be required. If the patient is resectable, pre-operative assessment of postoperative liver function is mandatory. After a curative resection, an adjuvant therapy may be administered. Otherwise, in cases with macroscopic residual disease after surgery or locally recurrent or unresectable cholangiocarcinoma at the diagnosis, first-line chemotherapy is the preferred strategy, possibly associated with radiotherapy and/or locoregional treatments. As the diagnostic and therapeutic pathway for cholangiocarcinoma can be declined in different modalities, patients should be promptly referred to a multidisciplinary team in a tertiary centre, familiar with this rare but lethal disease. Hence, the aim of the present paper is to focus on diagnostic and therapeutic algorithms based on the common guidelines and also on the clinical practice of multispecialist expert groups

Sustained complete response of advanced hepatocellular carcinoma with metronomic capecitabine: a report of three cases

Abstract Background Hepatocellular carcinoma (HCC) is one of the most frequent causes of cancer-related death. Sorafenib, a multitarget angiogenesis inhibitor, is an approved frontline treatment for advanced HCC in Western countries, although a complete response (CR) to treatment is infrequently reported. Capecitabine, an oral fluoropyrimidine, has been shown to be effect in both treatment-naïve patients and those previously treated with sorafenib. To date, however, only one case of sustained CR to metronomic capecitabine has been reported. Case presentation We describe three cases of advanced HCC treated with metronomic capecitabine where a CR was obtained. In the first case, capecitabine was administered as first line therapy; in the second case, capecitabine was used after intolerance to sorafenib; while in the third case, capecitabine was administered after sorafenib failure. Conclusion Capecitabine is a potentially important treatment option for patients with advanced HCC and may even represent a cure in certain cases

Do axis gut-breast microbiota orchestrate cancer progression?

: Breast cancer, even today, can cause death. Therefore, prevention and early detection are fundamental factors. The mechanisms that favour it are genetic and epigenetic and seems to play a significant role also the microbiota that can change estrogen levels and can induce chronic inflammation in the neoplastic site, alternating the balance between proliferation and cell death. Activated steroid hormone receptors induce transcription of genes that encode for proteins involved in cell proliferation and activate another transduction pathway, inducing cell cycle progression and cell migration. These important studies have allowed to develop therapies with selective modulators of estrogen receptors (SERMs), able to block their proliferative and pro-tumorigenic action. Of fundamental importance is also the role played by the microbiota in regulating the metabolism of estrogens and their levels in the blood. There are microbial populations, able to promote the development of breast cancer, through the production of enzymes responsible for the deconiugation of estrogens, the increase of these in the intestine, subsequent circulation and migration to other locations such as the udder. Other microbial populations are, instead, able to synthesize estrogen compounds similar or that mimic estrogenic action and to interfere with the metabolism of drugs, affecting the outcome of therapies. The microbial composition of the intestine and hormonal metabolism, depend largely on eating habits, the consumption of fats and proteins favours the increase of estrogen free in the blood, unlike a diet rich in fiber. Therefore, an in-depth knowledge of the microbiota present in the intestine-breast axis could, in the future, encourage the development of new diagnostic and therapeutic approaches in breast cancers

Expression of IRS1, insulin receptor, IGF1 receptor and ultrastructural differentiation in polarizing Caco-2 cells.

<p>Panel A shows western blot analysis of IRS1, beta subunit of the insulin receptor (InsRß), beta subunit of the insulin-like growth factor 1 receptor (IGF1Rß) and ß-actin, as loading control, in Caco-2 cells at days 3, 7 and 14 post-confluence, duplicated in absence (−) and presence (+) of serum in the culture medium. The histograms show quantitations, after normalization for ß-actin, of the IRS1, InsRß and IGF1Rß signals (means ± SE from the two experiments). Under both culture conditions increased espression of IRS1 and InsRß is clearly evident in polarized cells at day 14 (IRS1) and at days 7 and 14 (InsRß), whereas maximum expression of IGF1Rß is detected only at day 3. Transmission electron microscopy of Caco-2 cells at day 3 of the spontaneous polarization time course reveals forming electron-dense junctions at the apex of the lateral membranes of adjacent cells (panel A, arrow). With progression of polarization, tight junctions and desmosomes (panels C–D, arrows) and adhesion junctions (panel D) become evident as electron-dense plaques on adjacent lateral membranes at days 7 and 14, respectively. In addition, tight multicellular clusters, with differentiation features, such as intracellular lumina rich of apical brush border (panels E–F), become evident at day 14. Abbreviations: tj, tight junction; ad, adhesion junction; ds, desmosome. Panel G shows western blot levels of tyrosine 632-phosphorylated IRS1 (IRS1tyr632) and, as loading control, ß-actin, in serum-starved Caco-2 cells unstimulated (−) and stimulated (+) with insulin (100 nM) or IGF1 (10 nM). IRS1 tyrosine phosphorylation is relevant at day 7 of polarization, independently from the addition of exogenous insulin or IGF1. However, at day 3, only exogenous IGF1 determines IRS1 phosphorylation.</p