Case report: Precision guided reactive cancer management: molecular complete response in heavily pretreated metastatic CRC by dual immunotherapy and sorafenib.

Background: Metastatic colon adenocarcinoma presents significant challenges in treatment, particularly when resistant to standard therapies. Precision oncology, guided by multidisciplinary tumor boards (MTBs), offers a promising way for individualized therapeutic approaches. Integration of comprehensive genomic profiling (CGP) and minimal residual disease (MRD) testing strengthens treatment decision-making, yet challenges persist in identifying and overcoming resistance mechanisms. FLT3 amplification can be one of those resistance/escape mechanisms that needs to be targeted. Case presentation: This case report presents a 58-year-old male diagnosed with metastatic colon adenocarcinoma with liver metastasis, resistant to conventional treatments. Utilizing CGP and MRD testing, our multidisciplinary MTB identified a complex mutational profile, including APC, DAXX, TP53 mutations, and CDK8 and FLT3 amplifications. With a tumor mutational burden of 10 muts/mb and TPS, CPS scores of 0, immunotherapy was considered, employing dual immune checkpoint inhibitors alongside mebendazole and Lenvatinib targeting the WNT and VEGF/angiogenesis pathways. MRD testing revealed early treatment failure. Re-evaluation identified high copied FLT3 amplification (62 copies) as a resistance mechanism, prompting modification to incorporate sorafenib and dual immunotherapy with mebendazole. Subsequent MRD assessments and radiological scans demonstrated a remarkable therapeutic response, with sustained efficacy and absence of detectable residual disease. Conclusion: This case highlights the successful application of precision oncology principles, facilitated by dynamic MTB-guided treatment strategies. Integration of MRD testing provided early detection of treatment inefficacy, allowing for timely intervention and adaptation of the treatment plan. Additionally, the case highlights the educational value of rare molecular alterations, emphasizing continual learning and refinement of treatment approaches in precision oncology.

Alterations of ceramide synthesis induce PD-L1 internalization and signaling to regulate tumor metastasis and immunotherapy response.

Programmed death ligand 1, PD-L1 (CD274), facilitates immune evasion and exerts pro-survival functions in cancer cells. Here, we report a mechanism whereby internalization of PD-L1 in response to alterations of bioactive lipid/ceramide metabolism by ceramide synthase 4 (CerS4) induces sonic hedgehog (Shh) and transforming growth factor ß receptor signaling to enhance tumor metastasis in triple-negative breast cancers (TNBCs), exhibiting immunotherapy resistance. Mechanistically, data showed that internalized PD-L1 interacts with an RNA-binding protein, caprin-1, to stabilize Shh/TGFBR1/Wnt mRNAs to induce ß-catenin signaling and TNBC growth/metastasis, consistent with increased infiltration of FoxP3+ regulatory T cells and resistance to immunotherapy. While mammary tumors developed in MMTV-PyMT/CerS4-/- were highly metastatic, targeting the Shh/PD-L1 axis using sonidegib and anti-PD-L1 antibody vastly decreased tumor growth and metastasis, consistent with the inhibition of PD-L1 internalization and Shh/Wnt signaling, restoring anti-tumor immune response. These data, validated in clinical samples and databases, provide a mechanism-based therapeutic strategy to improve immunotherapy responses in metastatic TNBCs.

Targeting LINC00152 activates cAMP/Ca2+/ferroptosis axis and overcomes tamoxifen resistance in ER+ breast cancer.

Tamoxifen has been the mainstay therapy to treat early, locally advanced, and metastatic estrogen receptor-positive (ER + ) breast cancer, constituting around 75% of all cases. However, the emergence of resistance is common, necessitating the identification of novel therapeutic targets. Here, we demonstrated that long-noncoding RNA LINC00152 confers tamoxifen resistance by blocking tamoxifen-induced ferroptosis, an iron-mediated cell death. Mechanistically, inhibiting LINC00152 reduces the mRNA stability of phosphodiesterase 4D (PDE4D), leading to activation of the cAMP/PKA/CREB axis and increased expression of the TRPC1 Ca2+ channel. This causes cytosolic Ca2+ overload and generation of reactive oxygen species (ROS) that is, on the one hand, accompanied by downregulation of FTH1, a member of the iron sequestration unit, thus increasing intracellular Fe2+ levels; and on the other hand, inhibition of the peroxidase activity upon reduced GPX4 and xCT levels, in part by cAMP/CREB. These ultimately restore tamoxifen-dependent lipid peroxidation and ferroptotic cell death which are reversed upon chelating Ca2+ or overexpressing GPX4 or xCT. Overexpressing PDE4D reverses LINC00152 inhibition-mediated tamoxifen sensitization by de-activating the cAMP/Ca2+/ferroptosis axis. Importantly, high LINC00152 expression is significantly correlated with high PDE4D/low ferroptosis and worse survival in multiple cohorts of tamoxifen- or tamoxifen-containing endocrine therapy-treated ER+ breast cancer patients. Overall, we identified LINC00152 inhibition as a novel mechanism of tamoxifen sensitization via restoring tamoxifen-dependent ferroptosis upon destabilizing PDE4D, increasing cAMP and Ca2+ levels, thus leading to ROS generation and lipid peroxidation. Our findings reveal LINC00152 and its effectors as actionable therapeutic targets to improve clinical outcome in refractory ER+ breast cancer.

Durable radiologic and molecular complete response following nivolumab in an HNSCC patient with UV signature and HIV.

Cancer patients living with HIV (CPLWH) may experience increased mortality risk. Furthermore, they have been historically excluded from clinical trials due to safety concerns. Our patient with squamous cell carcinoma of the lower lip received radiotherapy and platinum-based chemotherapy but declined by multiple centers due to his accidental HIV status. Genomic profiling revealed CDKN2A/B, PBRM1, TP53, and TERT alterations corresponding to UV signature, and high tumor mutational burden with positive PD-L1 staining. Accordingly, we report a durable radiologic and molecular complete response upon nivolumab plus IVC and antiretroviral therapy (ART). We demonstrated the safety and efficacy of ICIs, and feasibility of managing adverse events caused by antitumor, antiviral, and integrative therapies.

Navigating uncharted territory: a case report and literature review on the remarkable response to personalized crizotinib containing combinational therapy in a pazopanib refractory patient with novel alterations.

This paper presents a patient with a novel Ig-like-III domain fibroblast growth factor receptor (FGFR2) alteration (W290_P307>C) along with CDKN2A/B alterations and a cadherin 1 (CDH1) alteration. Initial responsiveness to pazopanib monotherapy was encouraging, yet progression occurred after 7.5 months. Following progression, the molecular tumor board recommended a combination therapy approach comprising pazopanib, crizotinib, and palbociclib to target all of the changed pathways at the same time. Pazopanib was chosen to specifically target the FGFR2 alteration, while crizotinib was selected due to its potential synthetic lethality with the CDH1 alteration. In addition, the CDK4/6 inhibitor palbociclib was administered to address the CDKN2A/B alterations. The patient exhibited a remarkable and sustained response to this innovative combination. This case not only underscores the potential of tyrosine kinase inhibitors, exemplified by pazopanib, as a viable alternative for patients without access to pan-FGFR inhibitors, but it also emphasizes their efficacy beyond commonly detected point mutations and rearrangements. Notably, the outstanding response to combination therapy, including crizotinib, in a patient with a CDH1 alteration, further substantiates the preclinical evidence of synthetic lethality between crizotinib and CDH1 alterations. To our knowledge, this represents the first clinical evidence demonstrating the efficacy of crizotinib in a patient with a CDH1 alteration. Through careful dosage adjustments and consideration of individualized genomic information, this case exemplifies the power of personalized medicine in achieving favorable treatment outcomes.

PARP inhibitor combinations with high-dose vitamin C in the treatment of Ewing sarcoma: two case reports and mechanistic overview.

Ewing's sarcoma (ES) is a bone and soft tissue tumor that mainly occurs at a young age. The underlying cause of Ewing's sarcoma is the formation of fusion proteins between FET family genes and ETS family genes. Tumors with FET/ETS fusion genes can have defects in the DNA damage response and are sensitive to PARP inhibitors (PARPi). However, several studies have shown that PARPi alone is not sufficient to induce a meaningful antitumor response and that combinations of DNA-damaging agents with PARPi are required to achieve efficacy. Accordingly, preclinical studies have reported dramatic responses to PARPi treatment in combination with DNA-damaging agents such as temozolomide or irinotecan. Similarly, it has been previously reported that by generating reactive oxygen species, high-dose intravenous vitamin C (IVC) can induce DNA damage. This suggests that the combination of IVC with PARPi may increase genotoxic stress and enhance the antitumor response. In addition, unlike chemotherapeutic agents, IVC induces DNA damage selectively in cancer cells, and the side effects are significantly milder than those of chemotherapy. As ETS fusion-positive ES is deficient in faithful DNA repair, partly due to the interaction between ETS fusion products and PARP1, a PARPi plus IVC seems to be a logical and effective combination for the treatment of ETS fusion-positive ES. This paper reports significant responses to IVC (1-1.5 g/kg) in combination with PARPi (olaparib 300 mg BID or talazoparib 1 mg/day) in two patients with metastatic Ewing's sarcoma. The observations highlight an unmet therapeutic need for patients with advanced metastatic ES. The combination of PARPi with a selective DNA-damaging agent was effective in these cases. This case experience suggests that IVC may be incorporated into PARPi-based therapeutic strategies. Further studies are needed to confirm the efficacy of this combination in the treatment of Ewing sarcoma with ETS fusions.

Combining vitamin C with PARP inhibitors for Ewing sarcoma treatment: mechanistic insights and 2 case studies Ewing's sarcoma is a type of bone and soft tissue tumor that commonly affects young people and it is often resistant to conventional therapy. In this study, clinical cancer scientists and oncologists investigated a new approach to treating this cancer by combining high-dose vitamin C with PARP inhibitors. High-dose vitamin C can damage the DNA of cancer cells and PARP inhibitors block the damaged DNA sites so they can't be repaired and eventually this leads to cancer cells dying. The researchers found that when these two treatments were used together, there were significant improvements in two patients with advanced Ewing's sarcoma. Importantly, the combination led to fewer side effects compared to standard chemotherapy, suggesting it might be a more tolerable treatment option. These findings suggest that combining high-dose intravenous vitamin C with PARP inhibitors could be a promising treatment for Ewing's sarcoma. More research is needed to confirm these results, but this approach shows potential for helping patients with advanced forms of this type of cancer. This is the first clinical report demonstrating the benefits of using high-dose vitamin C with PARP inhibitors and the study emphasizes the importance of exploring more treatment options for this aggressive type of cancer and suggests that further investigations into this combined approach could lead to more effective and tolerable treatments for Ewing's sarcoma.

Toxic PARP trapping upon cAMP-induced DNA damage reinstates the efficacy of endocrine therapy and CDK4/6 inhibitors in treatment-refractory ER+ breast cancer.

Resistance to endocrine therapy and CDK4/6 inhibitors, the standard of care (SOC) in estrogen receptor-positive (ER+) breast cancer, greatly reduces patient survival. Therefore, elucidating the mechanisms of sensitivity and resistance to SOC therapy and identifying actionable targets are urgently needed. Here, we show that SOC therapy causes DNA damage and toxic PARP1 trapping upon generation of a functional BRCAness (i.e., BRCA1/2 deficiency) phenotype, leading to increased histone parylation and reduced H3K9 acetylation, resulting in transcriptional blockage and cell death. Mechanistically, SOC therapy downregulates phosphodiesterase 4D (PDE4D), a novel ER target gene in a feedforward loop with ER, resulting in increased cAMP, PKA-dependent phosphorylation of mitochondrial COXIV-I, ROS generation and DNA damage. However, during SOC resistance, an ER-to-EGFR switch induces PDE4D overexpression via c-Jun. Notably, combining SOC with inhibitors of PDE4D, EGFR or PARP1 overcomes SOC resistance irrespective of the BRCA1/2 status, providing actionable targets for restoring SOC efficacy.

Evaluation of the Relationship between Aromatase/Sirtuin1 Interaction and miRNA Expression in Human Neuroblastoma Cells.

BACKGROUND: Changes in activation/inhibition of Sirtuin-1 (SIRT1) and aromatase play an important role in a plethora of diseases. MicroRNAs (miRNAs) modulate multiple molecular pathways and affect a substantial number of physiological and pathological processes. OBJECTIVE: The aim of this study was to investigate any possible interaction between aromatase and SIRT1 in SH-SY5Y cells and to see how there is a connection between this interaction and miRNA expression, if there is an interaction. METHODS: In this study, cells were incubated in serum-deprived media for 6, 12, and 24 h. Aromatase and SIRT1 expressions were evaluated by Western blot. The IC50 concentration of SIRT1 activator (SRT1720), SIRT1 inhibitor (EX527), and aromatase inhibitors (letrozole and fadrozole) was determined by the XTT method. Then, CYP19A1 and SIRT1 levels were evaluated in the presence of SIRT1 siRNA or IC50 values for each activator/inhibitor. Finally, CYP19A1, SIRT1 expression and miRNA target gene were assessed with bioinformatic approaches. RESULTS: Aromatase and SIRT1 protein levels were significantly elevated in the cells incubated at 24 h in serum-deprived media (p ≤ 0.05). SIRT1 also positively regulated CYP19A1 in SH-SY5Y cells in media with/without FBS. Serum deprivation depending on time course caused changes in the oxidant/ antioxidant system. While oxidative stress index tended to decrease in the absence of FBS at 24 h compared to the control, it showed a significant decrease at 48 h in a serum-deprived manner (p ≤ 0.001). As a result of bioinformatics analysis, we determined 3 miRNAs that could potentially regulate SIRT1 and CYP19A1. hsa-miR-27a-3p and hsa-miR-181a-5p correlated in terms of their expressions at 24 h compared to 12 h, and there was a significant decrease in the expression of these miRNAs. On the contrary, the expression of hsa-miR-30c-5p significantly increased at 24 h compared to 12 h. CONCLUSION: Considering the results, a direct link between aromatase and SIRT1 was observed in human neuroblastoma cells. The identification of key miRNAs, hsa-miR-27a-3p, hsa-miR-30c-5p, and hsa-miR-181a-5p targeting both aromatase and SIRT1, provides an approach with novel insights on neurology-associated diseases.

Targeting LINC00152 activates cAMP/Ca2+/ferroptosis axis and overcomes tamoxifen resistance in ER+ breast cancer.

Tamoxifen has been the mainstay therapy to treat early, locally advanced, and metastatic estrogen receptor-positive (ER+) breast cancer, constituting around 75% of all cases. However, emergence of resistance is common, necessitating the identification of novel therapeutic targets. Here, we demonstrated that long-noncoding RNA LINC00152 confers tamoxifen resistance via blocking tamoxifen-induced ferroptosis, an iron-mediated cell death. Mechanistically, inhibiting LINC00152 reduces the mRNA stability of phosphodiesterase 4D (PDE4D), leading to activation of cAMP/PKA/CREB axis and increased expression of TRPC1 Ca2+ channel. This causes cytosolic Ca2+ overload and generation of reactive oxygen species (ROS) that is, on one hand, accompanied by downregulation of FTH1, a member of the iron sequestration unit, thus increasing intracellular Fe2+ levels; and on the other hand, inhibition of the peroxidase activity upon reduced GPX4 and xCT levels. These ultimately induce lipid peroxidation and ferroptotic cell death in combination with tamoxifen. Overexpressing PDE4D rescues LINC00152 inhibition-mediated tamoxifen sensitization by de-activating the cAMP/Ca2+/ferroptosis axis. Importantly, high LINC00152 expression is significantly correlated with high PDE4D/low ferroptosis and worse survival in multiple cohorts of tamoxifen- or tamoxifen-containing endocrine therapy-treated ER+ breast cancer patients. Overall, we identified LINC00152 inhibition as a novel mechanism of ferroptosis induction and tamoxifen sensitization, thereby revealing LINC00152 and its effectors as actionable therapeutic targets to improve clinical outcome in refractory ER+ breast cancer.

Targeting HIF1-alpha/miR-326/ITGA5 axis potentiates chemotherapy response in triple-negative breast cancer.

PURPOSE: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer that is frequently treated with chemotherapy. However, many patients exhibit either de novo chemoresistance or ultimately develop resistance to chemotherapy, leading to significantly high mortality rates. Therefore, increasing the efficacy of chemotherapy has potential to improve patient outcomes. METHODS: Here, we performed whole transcriptome sequencing (both RNA and small RNA-sequencing), coupled with network simulations and patient survival data analyses to build a novel miRNA-mRNA interaction network governing chemoresistance in TNBC. We performed cell proliferation assay, Western blotting, RNAi/miRNA mimic experiments, FN coating, 3D cultures, and ChIP assays to validate the interactions in the network, and their functional roles in chemoresistance. We developed xenograft models to test the therapeutic potential of the identified key miRNA/proteins in potentiating chemoresponse in vivo. We also analyzed several patient datasets to evaluate the clinical relevance of our findings. RESULTS: We identified fibronectin (FN1) as a central chemoresistance driver gene. Overexpressing miR-326 reversed FN1-driven chemoresistance by targeting FN1 receptor, ITGA5. miR-326 was downregulated by increased hypoxia/HIF1A and ECM stiffness in chemoresistant tumors, leading to upregulation of ITGA5 and activation of the downstream FAK/Src signaling pathways. Overexpression of miR-326 or inhibition of ITGA5 overcame FN1-driven chemotherapy resistance in vitro by inhibiting FAK/Src pathway and potentiated the efficacy of chemotherapy in vivo. Importantly, lower expression of miR-326 or higher levels of predicted miR-326 target genes was significantly associated with worse overall survival in chemotherapy-treated TNBC patients. CONCLUSION: FN1 is central in chemoresistance. In chemoresistant tumors, hypoxia and resulting ECM stiffness repress the expression of the tumor suppressor miRNA, miR-326. Hence, re-expression of miR-326 or inhibition of its target ITGA5 reverses FN1-driven chemoresistance making them attractive therapeutic approaches to enhance chemotherapy response in TNBCs.

Targeting lysyl oxidase (LOX) overcomes chemotherapy resistance in triple negative breast cancer.

Chemoresistance is a major obstacle in triple negative breast cancer (TNBC), the most aggressive breast cancer subtype. Here we identify hypoxia-induced ECM re-modeler, lysyl oxidase (LOX) as a key inducer of chemoresistance by developing chemoresistant TNBC tumors in vivo and characterizing their transcriptomes by RNA-sequencing. Inhibiting LOX reduces collagen cross-linking and fibronectin assembly, increases drug penetration, and downregulates ITGA5/FN1 expression, resulting in inhibition of FAK/Src signaling, induction of apoptosis and re-sensitization to chemotherapy. Similarly, inhibiting FAK/Src results in chemosensitization. These effects are observed in 3D-cultured cell lines, tumor organoids, chemoresistant xenografts, syngeneic tumors and PDX models. Re-expressing the hypoxia-repressed miR-142-3p, which targets HIF1A, LOX and ITGA5, causes further suppression of the HIF-1α/LOX/ITGA5/FN1 axis. Notably, higher LOX, ITGA5, or FN1, or lower miR-142-3p levels are associated with shorter survival in chemotherapy-treated TNBC patients. These results provide strong pre-clinical rationale for developing and testing LOX inhibitors to overcome chemoresistance in TNBC patients.

Comparison of two scleral incision techniques in 23-gauge transconjunctival vitrectomy.

BACKGROUND AND OBJECTIVE: To compare two 23-gauge transconjunctival vitrectomy incision techniques, parallel and perpendicular to the alignment of scleral fibers, in terms of hypotony and postoperative intraocular pressure (IOP). PATIENTS AND METHODS: Fifty-three eyes of 53 patients who underwent 23-gauge one-step trocar pars plana vitrectomy were randomly assigned to undergo scleral incision parallel (group 1, 26 eyes) or perpendicular (group 2, 27 eyes) to the limbus. Patients were observed postoperatively for wound healing, leakage, endophthalmitis, IOP, and hypotony at 1 day, 1 week, and 1, 3, 6, and 9 months. RESULTS: No difference in preoperative IOP was observed (P = .229). Postoperative IOP was significantly lower in group 2 (P = .009). Hypotony rates did not differ between the groups. Intraocular gas or silicone tamponade was used intraoperatively in 26 cases. In cases in which no gas or silicone was given (n = 27), IOP measurements were significantly lower in group 2 (P = .021). There was no difference in hypotony ratios for gas/silicone injection versus no injection (P = 1.00) or in postoperative visual acuity (P = .350). Visual acuity improved significantly in both groups at follow-up examinations. CONCLUSION: Parallel and perpendicular incisions resulted in similar postoperative hypotony rates, but perpendicular incisions were associated with lower IOP.

Optic disk analysis with heidelberg retina tomography in patients with branch retinal vein occlusion.

PURPOSE: To investigate the optic disk topography parameters of patients with branch retinal vein occlusion (BRVO) in a controlled study by using Heidelberg retinal tomography. METHODS: This prospective study included 35 eyes of 30 patients with BRVO who were followed-up at the Retina Clinic of the Ankara Ulucanlar Eye Education and Research Hospital, and 30 normal subjects (60 eyes). All patients and control subjects underwent complete ophthalmologic evaluation. The optic nerve heads of all subjects were imaged with the Heidelberg retinal tomography III (software 3.01a-M). The following stereometric parameters were calculated for each patient: disk area, cup area, cup-to-disk ratio, rim area, cup volume, rim volume, mean cup depth, maximum cup depth, and cup shape measure. Differences between the two groups were evaluated by the nonparametric independent sample t-test. RESULTS: The mean cup volume, rim volume, cup area, disk area, rim area, and cup depth in BRVO group were found to be statistically significantly smaller than those in the control group (P < 0.05). Significant differences in the same parameters were also noted between the unaffected and affected eyes in patients with BRVO (P < 0.05). No significant differences were found between the groups in terms of the other stereometric parameters (P > 0.05). CONCLUSION: Based on the results that were obtained in this series, a relationship was found between BRVO and various optic disk topography parameters determined by Heidelberg retinal tomography. Anatomical features of the optic disk may play a role in the pathogenesis of BRVO.

Early results of suprachoroidal drainage tube implantation for the surgical treatment of glaucoma.

PURPOSE: To evaluate the efficacy and safety of suprachoroidal silicone tube shunt implantation in glaucoma. PATIENTS AND METHODS: Twenty-four glaucomatous eyes unresponsive to medical treatment were included, 7 of them had earlier trabeculectomy. After preparation of a limbus-based scleral flap, 1.5 mm deep sclerotomy was made adjacent to scleral flap opening. Posterior end of the silicone tube was placed posteriorly in suprachoroidal space, anterior end was placed into anterior chamber. Intraocular pressure (IOP) and best corrected visual acuities (BCVA) were measured preoperatively and postoperatively on the first day, at the first week, in the first, third, sixth, twelfth, and eighteenth months. Postoperative IOP >21 mm Hg, <5 mm Hg (after 3 months), or additional glaucoma surgery were accepted as failure. Eyes not failed and not on supplemental medical therapy are considered as complete success. Eyes that have not failed, with or without supplemental medical therapy, are considered as qualified success. Hypotony was defined as early, when IOP below 5 mm Hg was observed within 4 weeks. RESULTS: Mean postoperative follow-up period was 34.4±23.7 weeks (range 4 to 78 wk). Complete success rates were 95.8%±4.1 at the first week, 79.2%±8.3 in the first and the third month, 63.3%±12.0 for the sixth and twelfth month. Qualified success rates were 95.8%±4.1 in the first week, 87.5%±6.8 in the first, third, sixth, twelfth months. Mean postoperative IOP's (8.5±4.9mm Hg, 12.9±5.6 mm Hg, 17.0±7.9 mm Hg, 15.3±3.6 mm Hg, 18.3±6.0, 15.1±6.0 mm Hg, respectively for the first week, first, third, sixth and twelfth mo) were significantly lower than preoperative mean IOP's. The success rates in cases without earlier trabeculectomy were significantly higher than in cases with earlier trabeculectomy (P=0.035). Postoperative first day mean±SD BCVA value was significantly lower than preoperative value (P=0.004). Failure was seen in 7 eyes of which 3 of them underwent reoperation for glaucoma. Early hypotony was seen in 6 eyes. No infection, choroidal, or retinal detachment was seen. There was a fibrin reaction in the anterior chamber in 3 patients. Two patients had intracameral bleeding, 1 of them underwent anterior chamber lavage. CONCLUSIONS: Suprachoroidal tube drainage of aqueous humor from the anterior chamber to the suprachoroidal space is effective in reducing IOP in glaucoma patients, with lower serious complication rates, and may be preferred as initial surgery in cases without earlier trabeculectomy.