Multi-omics staging of locally advanced rectal cancer predicts treatment response: a pilot study.

Treatment response assessment of rectal cancer patients is a critical component of personalized cancer care and it allows to identify suitable candidates for organ-preserving strategies. This pilot study employed a novel multi-omics approach combining MRI-based radiomic features and untargeted metabolomics to infer treatment response at staging. The metabolic signature highlighted how tumor cell viability is predictively down-regulated, while the response to oxidative stress was up-regulated in responder patients, showing significantly reduced oxoproline values at baseline compared to non-responder patients (p-value < 10-4). Tumors with a high degree of texture homogeneity, as assessed by radiomics, were more likely to achieve a major pathological response (p-value < 10-3). A machine learning classifier was implemented to summarize the multi-omics information and discriminate responders and non-responders. Combining all available radiomic and metabolomic features, the classifier delivered an AUC of 0.864 (± 0.083, p-value < 10-3) with a best-point sensitivity of 90.9% and a specificity of 81.8%. Our results suggest that a multi-omics approach, integrating radiomics and metabolomic data, can enhance the predictive value of standard MRI and could help to avoid unnecessary surgical treatments and their associated long-term complications.

Flow Cytometry Detection of Anthracycline-Treated Breast Cancer Cells: An Optimized Protocol.

The use of anthracycline derivatives was approved for the treatment of a broad spectrum of human tumors (i.e., breast cancer). The need to test these drugs on cancer models has pushed the basic research to apply many types of in vitro assays, and, among them, the study of anthracycline-induced apoptosis was mainly based on the application of flow cytometry protocols. However, the chemical structure of anthracycline derivatives gives them a strong autofluorescence effect that must be considered when flow cytometry is used. Unfortunately, the guidelines on the analysis of anthracycline effects through flow cytometry are lacking. Therefore, in this study, we optimized the flow cytometry detection of doxorubicin and epirubicin-treated breast cancer cells. Their autofluorescence was assessed both by using conventional and imaging flow cytometry; we found that all the channels excited by the 488 nm laser were affected. Anthracycline-induced apoptosis was then measured via flow cytometry using the optimized setting. Consequently, we established a set of recommendations that enable the development of optimized flow cytometry settings when the in vitro assays of anthracycline effects are analyzed, with the final aim to reveal a new perspective on the use of those in vitro tests for the further implementation of precision medicine strategies in cancer.

Whole breast radiotherapy in cN0 early breast cancer patients with pathological sentinel lymph nodes (pN1mic, pN1a) without axillary dissection: preliminary results of the observational LISEN trial.

PURPOSE: Axillary management remains unclear when sentinel lymph node (SLN) results are positive in cN0 patients with breast cancer (BC). The trial ACOSOG Z0011 represented a revolution with axillary lymph node dissection (ALND) omission in SLN+ patients, despite critiques regarding non-uniformity of radiation fields. We conducted an observational study (LISEN) where whole breast radiotherapy (WBRT) was planned with tangential fields without nodal irradiation in patients eligible for the Z0011 trial. METHODS: Inclusion criteria were female patients with histologically proven BC, cT1-2cN0, planned conservative surgery, no neoadjuvant therapy. Patients were stratified into two groups: micrometastatic (pN1mic, group 1) and macrometastatic (pN1a, group 2) lymph nodes. Tangential field WBRT was mandatory. Clinical outcomes were analysed, measured from surgery until the first event. RESULTS: In all, 199 patients underwent conservative surgery and SLN biopsy; 133 patients meeting criteria were analysed: 41 patients (30.8%) pN1mic and 92 (69.2%) pN1a. The 5­year disease-free survival (DFS) was 95.0% (85.9-100%) in group 1 and 93.0% (86.3-100.0%) in group 2 (p = 0.78). Overall survival (OS) was 100% (100-100%) in group 1 and 97.4% (92.4-100%) in group 2 (p = 0.74). For the whole cohort DFS and OS were 93.6% (88.2-99.4%) and 96.9% (91.5-100.0%), respectively. For groups 1 and 2, the 5­year outcomes were 5.0% (0.0-14.4%) and 2.3% (0.0-6.1%) for local recurrence (p = 0.51), and 6.2% (0.0-17.4%) and 7.0% (0.0-13.7%) for distant metastasis (p = 0.61), respectively. In group 1, regional recurrence (RR) and local regional recurrence (LRR) were 5.0% (0.0-14.1%; p = 0.13). In group 2, RR and LRR were 0.0% (0.0-0.0%). CONCLUSION: Our results showed good regional control in patients who met the Z0011 trial criteria. WBRT, without nodal surgery or RT, avoiding axillary morbidity, seems to be a good choice.

Impact of BMI on HER2+ metastatic breast cancer patients treated with pertuzumab and/or trastuzumab emtansine. Real-world evidence.

Body mass index (BMI) is a main indicator of obesity and its association with breast cancer is well established. However, little is known in the metastatic setting, especially in HER2-positive patients. We assessed the influence of BMI on clinical outcomes of patients treated with pertuzumab and/or trastuzumab emtansine (T-DM1) for HER2+ metastatic breast cancer (mBC). BMI was addressed as a categorical variable, being classified on the basis of the following ranges, that is, 18.5-24.9, 25-29.9, and 30.0-34.9, namely, normal weight, overweight, and Class I obesity. The outcomes chosen were progression-free survival to first-line chemotherapy (PFS1) and overall survival (OS). Overall (N = 709), no impact of BMI was observed on PFS1 (p = .15), while BMI ≥ 30 was associated with worse OS (p = .003). In subjects who progressed to first line (N = 575), analyzing data across PFS1 quartiles and strata of disease burden, BMI predicted lower PFS1 in patients within the I PFS1 quartile and with the lowest disease burden (p = .001). Univariate analysis showed a detrimental effect of BMI ≥ 30 on OS for women within the I PFS1 quartile (p = .03). Results were confirmed in multivariate analysis. According to PFS1 quartiles a higher percentage of patients with high BMI and low disease burden progressed within 6 months of therapy. The effect of BMI on prognosis was also confirmed in multivariate analysis of OS for overall population. In our cohort, a BMI ≥ 30 correlated with worse OS in patients with HER2+ mBC who received pertuzumab and/or T-DM1 but had no impact on PFS to first line. BMI predicted worse I PFS1 quartile.

Distinct HR expression patterns significantly affect the clinical behavior of metastatic HER2+ breast cancer and degree of benefit from novel anti-HER2 agents in the real world setting.

We analyzed data from 738 HER2-positive metastatic breast cancer (mbc) patients treated with pertuzumab-based regimens and/or T-DM1 at 45 Italian centers. Outcomes were explored in relation to tumor subtype assessed by immunohistochemistry (IHC). The median progression-free survival at first-line (mPFS1) was 12 months. Pertuzumab as first-line conferred longer mPFS1 compared to other first-line treatments (16 vs. 9 months, p = 0.0001), regardless of IHC subtype. Median PFS in second-line (mPFS2) was 7 months, with no difference by IHC subtype, but it was more favorable with T-DM1 compared to other agents (7 vs. 6 months, p = 0.03). There was no PFS2 gain in patients with tumors expressing both hormonal receptors (HRs; p = 0.17), while a trend emerged for tumors with one HR (p = 0.05). Conversely, PFS2 gain was significant in HRs-negative tumors (p = 0.04). Median overall survival (mOS) was 74 months, with no significant differences by IHC subtypes. Survival rates at 2 and 3 years in patients treated with T-DM1 in second-line after pertuzumab were significantly lower compared to pertuzumab-naïve patients (p = 0.01). When analyzed by IHC subtype, the outcome was confirmed if both HRs or no HRs were expressed (p = 0.02 and p = 0.006, respectively). Our results confirm that HRs expression impacts the clinical behavior and novel treatment-related outcomes of HER2-positive tumors when treatment sequences are considered. Moreover, multivariate analysis showed that HRs expression had no effect on PFS and OS. Further studies are warranted to confirm our findings and clarify the interplay between HER2 and estrogen receptor pathways in HER2-positive (mbc) patients.

Palbociclib plus endocrine therapy in HER2 negative, hormonal receptor-positive, advanced breast cancer: A real-world experience.

Data from 423 human epidermal growth factor receptor 2-negative (HER2-), hormone receptor-positive (HR+) advanced breast cancer (aBC) patients treated with palbociclib and endocrine therapy (ET) were provided by 35 Italian cancer centers and analyzed for treatment outcomes. Overall, 158 patients were treated in first line and 265 in second/later lines. We observed 19 complete responses and 112 partial responses. The overall response rate (ORR) was 31% (95% confidence interval [CI], 26.6-35.4) and clinical benefit was 52.7% (95% CI, 48-57.5). ORR was negatively affected by prior exposure to everolimus/exemestane ( p = 0.002) and favorably influenced by early line-treatment ( p < 0.0001). At 6 months, median progression-free survival was 12 months (95% CI, 8-16) and median overall survival was 24 months (95% CI, 17-30). More favorable outcomes were associated with palbociclib in early lines, no visceral metastases and no prior everolimus/exemestane. The main toxicity reported was neutropenia. Our results provide further support to the use of palbociclib with ET in HER2-, HR+ aBC. Differences in outcomes across patients subsets remain largely unexplained.

Clinical Outcomes of Patients with Advanced Cancer and Pre-Existing Autoimmune Diseases Treated with Anti-Programmed Death-1 Immunotherapy: A Real-World Transverse Study.

BACKGROUND: Patients with a history of autoimmune diseases (AIDs) have not usually been included in clinical trials with immune checkpoint inhibitors. MATERIALS AND METHODS: Consecutive patients with advanced cancer, treated with anti-programmed death-1 (PD-1) agents, were evaluated according to the presence of pre-existing AIDs. The incidence of immune-related adverse events (irAEs) and clinical outcomes were compared among subgroups. RESULTS: A total of 751 patients were enrolled; median age was 69 years. Primary tumors were as follows: non-small cell lung cancer, 492 (65.5%); melanoma, 159 (21.2%); kidney cancer, 94 (12.5%); and others, 6 (0.8%). Male/female ratio was 499/252. Eighty-five patients (11.3%) had pre-existing AIDs, further differentiated in clinically active (17.6%) and inactive (82.4%). Among patients with pre-existing AIDs, incidence of irAEs of any grade was significantly higher when compared with patients without AIDs (65.9% vs. 39.9%). At multivariate analysis, both inactive (p = .0005) and active pre-existing AIDs (p = .0162), female sex (p = .0004), and Eastern Cooperative Oncology Group Performance Status <2 (p = .0030) were significantly related to a higher incidence of irAEs of any grade. No significant differences were observed regarding grade 3/4 irAEs and objective response rate among subgroups. Pre-existing AIDs were not significantly related with progression-free survival and overall survival. CONCLUSION: This study quantifies the increased risk of developing irAEs in patients with pre-existing AIDs who had to be treated with anti-PD-1 immunotherapy. Nevertheless, the incidence of grade 3/4 irAEs is not significantly higher when compared with control population. The finding of a greater incidence of irAEs among female patients ranks among the "hot topics" in gender-related differences in immuno-oncology. IMPLICATIONS FOR PRACTICE: Patients with a history of autoimmune diseases (AIDs) have not usually been included in clinical trials with immune checkpoint inhibitors but are frequent in clinical practice. This study quantifies the increased risk of developing immune-related adverse events (irAEs) in patients with pre-existing AIDs who had to be treated with anti-programmed death-1 immunotherapy. Nevertheless, their toxicities are mild and the incidence of grade 3/4 irAEs is not significantly higher compared with those of controls. These results will help clinicians in everyday practice, improving their ability to offer a proper counselling to patients, in order to offer an immunotherapy treatment even to patients with pre-existing autoimmune disease.

PLC-gamma-1 phosphorylation status is prognostic of metastatic risk in patients with early-stage Luminal-A and -B breast cancer subtypes.

BACKGROUND: Phospholipase Cγ1 (PLCγ1) is highly expressed in human tumours. Our previous studies reported that both stable and inducible PLCγ1 down-regulation can inhibit formation of breast-cancer-derived experimental lung metastasis. Further, high expression of PLCγ1 and its constitutively activated forms (i.e., PLCγ1-pY1253, PLCγ1-pY783) is associated with worse clinical outcome in terms of incidence of distant metastases, but not of local relapse in T1-T2, N0 breast cancer patients. METHODS: In the present retrospective study, we analysed the prognostic role of PLCγ1 in early breast cancer patients stratified according to the St. Gallen criteria and to their menopausal status. PLCγ1-pY1253 and PLCγ1-pY783 protein expression levels were determined by immunohistochemistry on tissue microarrays, and were correlated with patients' clinical data, using univariate and multivariate statistical analyses. RESULTS: In our series, the prognostic value of PLCγ1 overexpression was restricted to Luminal type tumours. From multivariate analyses, pY1253-PLCγ1High was an independent prognostic factor only in postmenopausal patients with Luminal-B tumours (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.1-5.3; P = 0.034). Conversely, PLCγ1-pY783High was a remarkably strong risk factor (HR, 20.1; 95% CI, 2.2-178.4; P = 0.003) for pre/perimenopausal patients with Luminal-A tumours. CONCLUSIONS: PLCγ1 overexpression is a strong predictive surrogate marker of development of metastases in early Luminal-A and -B breast cancer patients, being able to discriminate patients with high and low risk of metastases. Therefore, targeting the PLCγ1 pathway can be considered of potential benefit for prevention of metastatic disease.

Intratumoral Delivery of Immunotherapy-Act Locally, Think Globally.

Immune mechanisms have evolved to cope with local entry of microbes acting in a confined fashion but eventually inducing systemic immune memory. Indeed, in situ delivery of a number of agents into tumors can mimic in the malignant tissue the phenomena that control intracellular infection leading to the killing of infected cells. Vascular endothelium activation and lymphocyte attraction, together with dendritic cell-mediated cross-priming, are the key elements. Intratumoral therapy with pathogen-associated molecular patterns or recombinant viruses is being tested in the clinic. Cell therapies can be also delivered intratumorally, including infusion of autologous dendritic cells and even tumor-reactive T lymphocytes. Intralesional virotherapy with an HSV vector expressing GM-CSF has been recently approved by the Food and Drug Administration for the treatment of unresectable melanoma. Immunomodulatory monoclonal Abs have also been successfully applied intratumorally in animal models. Local delivery means less systemic toxicity while focusing the immune response on the malignancy and the affected draining lymph nodes.

Long-term performance of risk scores for venous thromboembolism in ambulatory cancer patients.

The long-term performance of prediction scores for venous thromboembolism (VTE) in cancer patients has been poorly investigated. We evaluated the discriminatory performance of the Khorana, PROTECHT, CONKO, and ONKOTEV scores for the first 3-6 months and for 12 months, and re-assessed scores after 3-6 months to determine the influence of variations in patients' risk classification on performance. Retrospective cohort of ambulatory patients with active cancer who were scheduled to receive first or new line of chemotherapy. The primary outcome was symptomatic or incidental VTE. A total of 776 patients were included of whom 540 (70%) had distant metastases. The time-dependent c-statistics of Khorana, PROTECHT, CONKO, and ONKOTEV scores at 6 months were 0.61 (95% CI 0.56 to 0.66), 0.61 (95% CI 0.55 to 0.66), 0.60 (95% CI 0.54 to 0.66), and 0.59 (0.52 to 0.66), respectively, with a tendency to decrease during follow-up. None of the scores discriminated between high and low risk patients at the conventional 3-point positivity threshold. The use of a 2-point positivity threshold improved performance of all scores and captured a higher proportion of VTE. The accuracy of risk scores re-assessed at 3-6 months was modest. The Khorana, PROTECHT, CONKO, and ONKOTEV scores are not sufficiently accurate when used at a conventional threshold of 3 points. Performance improves at positivity threshold of 2 points, as evaluated in recent randomized studies on VTE prophylaxis. Score accuracy tends to decrease over time suggesting the need of periodic re-evaluation to estimate possible variation of risk.

Neoadjuvant chemotherapy in triple-negative breast cancer: A multicentric retrospective observational study in real-life setting.

We aimed to assess the efficacy of neoadjuvant chemotherapy (NACT) in a cohort of 213 triple-negative breast cancer (TNBC) patients treated in real-world practice at eight Italian cancer centers. We computed descriptive statistics for all the variable of interest. Factors testing significant in univariate analysis were included in multivariate models. Survival data were compared by Kaplan-Meier curves and log-rank test. The median follow-up was 45 months. We observed 60 (28.2%) pathological complete response (pCR). The sequential anthracyclines-taxanes-based regimens produced the highest rate of pCR (42.6%), followed by concomitant anthracycline-taxane (24.2%), and other regimens (15.6%) (p = 0.008). When analyzing the role of baseline Ki-67, a 50% cut-off was the optimal threshold value for pCR prediction (p = 0.0005). The 5-year disease-free survival (DFS) was 57.3% and the 5-year overall survival (OS) was 70.8%. In patients not achieving pCR, the optimal Ki-67 variation between biopsy and surgical specimen with prognostic relevance on long-term outcomes was 13% (p = 0.04). Patients with a Ki-67 reduction (rKi-67)<13% had worse outcomes compared to those who experienced pCR or a rKi-67≥13%. The number of NACT cycles also affected long-term outcomes (5-year DFS 65.7% vs 51.6% in patients having received >6 cycles compared with their counterparts, p = 0.02). In multivariate analysis, node status, grading, and bio-pathological treatment response (including pCR and rKi-67) impacted DFS and OS. Our results confirmed the advantage conferred by more than 6 cycles of a sequential antracycline-taxane-based NACT. Higher baseline Ki-67 values shows greater predictive significance on pathogical response, while the rKi-67 plays a prognostic role on long-term outcomes.

90K immunostimulatory glycoprotein in children with juvenile idiopathic arthritis.

OBJECTIVES: To assess whether circulating levels of 90K glycoprotein are increased in children with juvenile idiopathic arthritis (JIA) at different stages of the disease, compared to healthy controls and to evaluate potential over time changes in its concentrations following treatment with the antitumor-necrosis factor (TNF) drug etanercept. METHODS: 90K glycoprotein, C-reactive protein, erythrocyte sedimentation rate, TNF, antinuclear antibodies, rheumatoid factor and the Juvenile Arthritis Disease Activity Score were assessed in 71 children: 23 with newly diagnosed JIA, 23 with established and active JIA and 25 healthy controls. Patients, eligible for anti-TNF treatment, underwent a similar clinical/laboratory assessment after 6- and 12-month etanercept therapy. RESULTS: At baseline, significant differences were found in 90K levels between the three study groups: JIA at onset (157.7 [131.4-241.5] µg/ml), JIA on treatment (90.0 [68.8-120.2] µg/ml) and control group (58.0 [44.5-79.0] µg/ml), (p for trend <.001), with the JIA at onset group showing the highest values. In the JIA on treatment group, following one-year etanercept treatment, a significant reduction in 90K was detected already at 6 months (74.3 [56.0-104.1] µg/ml p = .001) and a further decline was observed at 12 months (49.3 [46.0-67.6] µg/ml p < .001). CONCLUSION: Our study showed that 90K glycoprotein levels are increased in JIA children compared to healthy controls, suggesting a potential pathogenetic role in the JIA. Besides, 12 months of therapy with etanercept can reduce 90K levels.

Prognostic relevance of LGALS3BP in human colorectal carcinoma.

BACKGROUND: A previous report has shown that LGALS3BP (also known as 90K or Mac-2 BP) has antitumor activity in colorectal cancer (CRC) via suppression of Wnt signalling with a novel mechanism of ISGylation-dependent ubiquitination of ß-catenin. The role of LGALS3BP in CRC prognosis was investigated. METHODS: The role of LGALS3BP on CRC progression and clinical prognosis was analyzed by combining cell cultures, in vitro assays, and immunohistochemistry. RESULTS: Silencing of LGALS3BP in HCT-116 human colon cancer cells resulted in enhanced ß-catenin expression that was reversed by addition of human recombinant LGALS3BP. Moreover, intra-tumor delivery of LGALS3BP reduced tumor growth of xenografts originating from LGALS3BP-silenced HCT-116 cells. Finally, in a series of 196 CRC patients, LGALS3BP expression in tumor tissue associated with clinical outcome. Patients with high LGALS3BP expression had lower risk of relapse and a longer overall survival time than those with low LGALS3BP expression. Multivariate analyses confirmed LGALS3BP expression status as the only independent prognostic factor of survival. CONCLUSIONS: These results provide evidence that low expression of LGALS3BP participates in malignant progression of CRC and implicates poor prognosis, highlighting its augmentation as a potential therapeutic approach.

Outcomes of HER2-positive early breast cancer patients in the pre-trastuzumab and trastuzumab eras: a real-world multicenter observational analysis. The RETROHER study.

Addition of trastuzumab to adjuvant chemotherapy has dramatically reduced the risk of recurrence and has become the standard of care for human epidermal growth factor receptor 2 (HER2)-positive early breast cancer patients. Since most data on trastuzumab benefits come from clinical trials, conducted in selected patient populations, we performed a retrospective analysis of HER2-positive early breast cancer patients treated in the "pre-trastuzumab" and "trastuzumab" eras, with the aim to determine patients' outcomes in real-world practice. 925 consecutive HER2-positive breast cancer patients treated with adjuvant chemotherapy in ten Italian oncologic centers were identified. Patients who had received adjuvant chemotherapy alone (cohort A, 352 patients), and patients who had received adjuvant chemotherapy followed or combined with trastuzumab (cohort B, 573 patients) were analyzed. Relapse rate at 3 years, relapse-free survival, and overall survival were significantly more unfavorable in the cohort A than in the cohort B (p < 0.0001). In multivariate analysis, factors related to relapse were younger age, advanced stage at diagnosis, absence of hormonal and of trastuzumab therapy. The benefit derived from the addition of trastuzumab was independent of nodal status and hormonal receptors expression. A subgroup analysis including 163 "triple positive" tumors with high levels of estrogen and progesterone receptor (TP50) suggested that addition of trastuzumab to adjuvant chemotherapy and hormonal therapy did not translate into better outcomes. In our analysis, trastuzumab benefit was confirmed in all but a small subset of TP50 tumors subgroups. In this subset further investigations are needed.

Long-term outcome of neoadjuvant endocrine therapy with aromatase inhibitors in elderly women with hormone receptor-positive breast cancer.

BACKGROUND: Aromatase inhibitors (AIs) are more effective than tamoxifen as neoadjuvant endocrine therapy (NET) for hormone receptor (HR)-positive breast cancer. Here we report the surgical and long-term outcome of elderly postmenopausal patients with locally advanced, HR-positive breast cancer treated with preoperative AIs. METHODS: Between January 2003 and December 2012, 144 postmenopausal patients inoperable with breast conservative surgery (BCS) received letrozole, anastrozole, or exemestane as NET. Patients underwent breast surgery and received adjuvant AIs. Adjuvant systemic therapy, chemotherapy and/or trastuzumab, and adjuvant radiotherapy were administered as appropriate, but limited to high-risk patients with few or no comorbidities. RESULTS: After a median follow-up of 49 months, 4 (3.0 %) patients had local relapse, 18 (12.5 %) had distant metastases, and 24 (17.0 %) died. BCS was performed in 121 (84.0 %) patients. A tumor size <3 cm and human epidermal growth factor receptor 2 (HER2) negativity were predictors of BCS. The achievement of BCS and grade G1 were significantly associated with longer disease-free survival (DFS) (p = 0.009 and p = 0.01, respectively) and overall survival (p = 0.002 and p = 0.005, respectively). Residual tumor ≤2 cm (yT0-yT1) in the longest diameter after NET was also statistically associated with longer DFS (p = 0.005). CONCLUSIONS: The results of this retrospective study indicate that elderly breast cancer patients with a tumor size <3 cm at diagnosis and HER2 negativity have a higher probability of achieving BCS after NET. Moreover, patients treated with BCS and with grade G1 tumor have a reduced risk of recurrence and death in the long-term follow-up.

Overexpression of activated phospholipase Cγ1 is a risk factor for distant metastases in T1-T2, N0 breast cancer patients undergoing adjuvant chemotherapy.

Phospholipase Cγ1 (PLCγ1) is highly expressed in several tumors. We have previously reported that both stable and inducible PLCγ1 down-regulation resulted in an almost complete inhibition of breast cancer-derived experimental lung metastasis formation. The aim of our study is to evaluate the association between the expression of PLCγ1 and of PLCγ1 phosphorylated at Tyr1253 (PLCγ1-pY1253) and at Tyr783 (PLCγ1-pY783) with the clinical outcome of patients with node negative, T1/T2 breast cancers. The study groups consisted of 292 (training set) and 122 (validation set) patients presenting with primary unilateral breast carcinoma (T1-T2), with no evidence of nodal involvement and distant metastases. PLCγ1, PLCγ1-pY1253 and PLCγ1-pY783 protein expression were assessed by immunohistochemistry on tissue microarrays and the results correlated with the clinical data using Kaplan-Meier curves and multivariate Cox regression analysis. Tumor cells while expressing variable proportions of cytoplasmic PLCγ1, express PLCγ1-pY1253 and PLCγ1-pY783 predominantly in the nucleus. High expression of PLCγ1, and of its activated forms, is associated with a worse clinical outcome in terms of incidence of distant metastases, and not of local relapse in T1-T2, N0 breast cancer patients undergone adjuvant chemotherapy. PLCγ1 over-expression appears to be a reliable predictive surrogate marker of development of metastases. Thus, targeting PLCγ1 pathways might represent a potential therapeutic approach for the prevention of metastatic disease in breast cancer.

The 2EF Antibody Targets a Unique N-Terminal Epitope of Trop-2 and Enhances the In Vivo Activity of the Cancer-Selective 2G10 Antibody.

Trop-2 proteolytic processing in cancer cells exposes epitopes that were specifically targeted by the 2G10 antibody. We sought additional recognition of Trop-2 within difficult-to-reach, densely packed tumor sites. Trop-2 deletion mutants were employed in immunization and screening procedures, and these led to the recognition of a novel epitope in the N-terminal region of Trop-2, by the 2EF antibody. The 2EF mAb was shown to bind Trop-2 at cell-cell junctions in MCF-7 breast cancer cells, and in deeply seated sites in prostate cancer, that were inaccessible to benchmark anti-Trop-2 antibodies. The 2EF antibody was shown to inhibit the growth of HT29 colon tumor cells in vitro, with the highest activity at high cell density. In vivo, 2EF showed anticancer activity against SKOv3 ovarian, Colo205, HT29, HCT116 colon and DU-145 prostate tumors, with the highest impact on densely packed tumor sites, whereby 2EF outcompeted benchmark anti-Trop-2 antibodies. Given the different recognition modes of Trop-2 by 2EF and 2G10, we hypothesized the effective interaction of the two mAb in vivo. The 2EF mAb was indeed demonstrated to enhance the activity of 2G10 against tumor xenotransplants, opening novel avenues for Trop-2-targeted therapy. We humanized 2EF by state-of-the-art CDR grafting/re-modeling, yielding the Hu2EF for therapy of Trop-2-expressing tumors in patients.

Phylogenetic conservation of Trop-2 across species-rodent and primate genomics model anti-Trop-2 therapy for pre-clinical benchmarks.

A phylogenetic conservation analysis of Trop-2 across vertebrate species showed a high degree of sequence conservation, permitting to explore multiple models as pre-clinical benchmarks. Sequence divergence and incomplete conservation of expression patterns were observed in mouse and rat. Primate Trop-2 sequences were found to be 95%-100% identical to the human sequence. Comparative three-dimension primate Trop-2 structures were obtained with AlphaFold and homology modeling. This revealed high structure conservation of Trop-2 (0.66 ProMod3 GMQE, 0.80-0.86 ± 0.05 QMEANDisCo scores), with conservative amino acid changes at variant sites. Primate TACSTD2/TROP2 cDNAs were cloned and transfectants for individual ORF were shown to be efficiently recognized by humanized anti-Trop-2 monoclonal antibodies (Hu2G10, Hu2EF). Immunohistochemistry analysis of Macaca mulatta (rhesus monkey) tissues showed Trop-2 expression patterns that closely followed those in human tissues. This led us to test Trop-2 targeting in vivo in Macaca fascicularis (cynomolgus monkey). Intravenously injected Hu2G10 and Hu2EF were well tolerated from 5 to 10 mg/kg. Neither neurological, respiratory, digestive, urinary symptoms, nor biochemical or hematological toxicities were detected during 28-day observation. Blood serum pharmacokinetic (PK) studies were conducted utilizing anti-idiotypic antibodies in capture-ELISA assays. Hu2G10 (t1/2 = 6.5 days) and Hu2EF (t1/2 = 5.5 days) were stable in plasma, and were detectable in the circulation up to 3 weeks after the infusion. These findings validate primates as reliable models for Hu2G10 and Hu2EF toxicity and PK, and support the use of these antibodies as next-generation anti-Trop-2 immunotherapy tools.

CAR-T-Derived Extracellular Vesicles: A Promising Development of CAR-T Anti-Tumor Therapy.

Extracellular vesicles (EVs) are a heterogenous population of plasma membrane-surrounded particles that are released in the extracellular milieu by almost all types of living cells. EVs are key players in intercellular crosstalk, both locally and systemically, given that they deliver their cargoes (consisting of proteins, lipids, mRNAs, miRNAs, and DNA fragments) to target cells, crossing biological barriers. Those mechanisms further trigger a wide range of biological responses. Interestingly, EV phenotypes and cargoes and, therefore, their functions, stem from their specific parental cells. For these reasons, EVs have been proposed as promising candidates for EV-based, cell-free therapies. One of the new frontiers of cell-based immunotherapy for the fight against refractory neoplastic diseases is represented by genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes, which in recent years have demonstrated their effectiveness by reaching commercialization and clinical application for some neoplastic diseases. CAR-T-derived EVs represent a recent promising development of CAR-T immunotherapy approaches. This crosscutting innovative strategy is designed to exploit the advantages of genetically engineered cell-based immunotherapy together with those of cell-free EVs, which in principle might be safer and more efficient in crossing biological and tumor-associated barriers. In this review, we underlined the potential of CAR-T-derived EVs as therapeutic agents in tumors.

3D-Informed Targeting of the Trop-2 Signal-Activation Site Drives Selective Cancer Vulnerability.

Next-generation Trop-2-targeted therapy against advanced cancers is hampered by expression of Trop-2 in normal tissues. We discovered that Trop-2 undergoes proteolytic activation by ADAM10 in cancer cells, leading to the exposure of a previously inaccessible protein groove flanked by two N-glycosylation sites. We designed a recognition strategy for this region, to drive selective cancer vulnerability in patients. Most undiscriminating anti-Trop-2 mAbs recognize a single immunodominant epitope. Hence, we removed it by deletion mutagenesis. Cancer-specific, glycosylation-prone mAbs were selected by ELISA, bio-layer interferometry, flow cytometry, confocal microscopy for differential binding to cleaved/activated, wild-type and glycosylation site-mutagenized Trop-2. The resulting 2G10 mAb family binds Trop-2-expressing cancer cells, but not Trop-2 on normal cells. We humanized 2G10 by state-of-the-art complementarity determining region grafting/re-modeling, yielding Hu2G10. This antibody binds cancer-specific, cleaved/activated Trop-2 with Kd < 10-12 mol/L, and uncleaved/wtTrop-2 in normal cells with Kd 3.16×10-8 mol/L, thus promising an unprecedented therapeutic index in patients. In vivo, Hu2G10 ablates growth of Trop-2-expressing breast, colon, prostate cancers, but shows no evidence of systemic toxicity, paving the way for a paradigm shift in Trop-2-targeted therapy.