Case report: From negative to positive: a remarkable journey of ER, PR and HER2 status in a patient with metastatic breast cancer.

Breast cancer is the most common malignant tumor in women, posing a serious threat to women's health. HER2 has been identified as a key oncogene and prognostic factor in breast cancer. Recent studies have reported inconsistencies in ER, PR, and/or HER2 expression between primary breast tumors and metastatic lesions. Rarely is it reported that all three biomarkers experience conversion. In this report, we present the case of a female patient with relapsed and metastatic breast cancer, whose histology transformed from initially triple-negative to Luminal-B type (HER2 positive) (i.e., ER, PR, and HER2 positive). She underwent systematic chemotherapy, targeted therapy, and cranial radiotherapy, which was followed by maintenance treatment with targeted and endocrine therapy. Currently, she has been in nearly complete remission (nCR) for more than 12 months. For recurrent and metastatic breast cancer, it is necessary to perform the second biopsy for metastases, which would contribute to precision treatment and prognosis improvement.

Furmonertinib for EGFR-mutant advanced non-small cell lung cancer: a glittering diamond in the rough of EGFR-TKI.

The third-generation EGFR-TKIs, such as osimertinib, aumolertinib, and furmonertinib, have been recommended as the preferred treatment for EGFR-mutant advanced non-small cell lung cancer (NSCLC). Among them, furmonertinib shows several advantages in terms of clinical efficacy. Firstly, compared to osimertinib and aumolertinib, furmonertinib was the first EGFR-TKI with median progression-free survival (mPFS) of over 20.0 m (20.8 m) for advanced NSCLC with classical EGFR-mutations. Furthermore, furmonertinib achieved a mPFS of 18.1 m in advanced NSCLC with unfavorable prognostic factors, such as the 21 L858R mutation and central nervous system (CNS) metastasis, which is unrivalled by osimertinib. Secondly, furmonertinib is the only FDA-approved EGFR-TKI for breakthrough therapy in newly-diagnosed advanced NSCLC with EGFR ex20ins mutation. Thirdly, the relatively longer mPFS of 20.8 m was observed in furmonertinib compared to osimertinib and aumolertinib (15.2 m and 15.3 m) in EGFR-mutant advanced NSCLC with CNS metastases. More importantly, the efficacy of furmonertinib increases within the dose range of 80-240 mg per day. Finally, furmonertinib can be an optional treatment for advanced NSCLC patients who develop resistance to osimertinib or aumolertinib. In conclusion, furmonertinib may be a glittering star in the field of EGFR-TKI, which requires further exploration and expansion.

Red blood cell-derived materials for cancer therapy: Construction, distribution, and applications.

Cancer has become an increasingly important public health issue owing to its high morbidity and mortality rates. Although traditional treatment methods are relatively effective, they have limitations such as highly toxic side effects, easy drug resistance, and high individual variability. Meanwhile, emerging therapies remain limited, and their actual anti-tumor effects need to be improved. Nanotechnology has received considerable attention for its development and application. In particular, artificial nanocarriers have emerged as a crucial approach for tumor therapy. However, certain deficiencies persist, including immunogenicity, permeability, targeting, and biocompatibility. The application of erythrocyte-derived materials will help overcome the above problems and enhance therapeutic effects. Erythrocyte-derived materials can be acquired via the application of physical and chemical techniques from natural erythrocyte membranes, or through the integration of these membranes with synthetic inner core materials using cell membrane biomimetic technology. Their natural properties such as biocompatibility and long circulation time make them an ideal choice for drug delivery or nanoparticle biocoating. Thus, red blood cell-derived materials are widely used in the field of biomedicine. However, further studies are required to evaluate their efficacy, in vivo metabolism, preparation, design, and clinical translation. Based on the latest research reports, this review summarizes the biology, synthesis, characteristics, and distribution of red blood cell-derived materials. Furthermore, we provide a reference for further research and clinical transformation by comprehensively discussing the applications and technical challenges faced by red blood cell-derived materials in the treatment of malignant tumors.

Case report: Olverembatinib monotherapy: the chemotherapy-free regimen for an elderly patient with relapsed Ph-positive acute lymphoblastic leukemia.

Background: The advent of first- and second-generation BCR/ABL1 tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, has markedly improved the clinical outcomes of patients with philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+-ALL). However, due to acquired drug resistance, most Ph+-ALL patients experience relapse. Thus, third-generation BCR/ABL1 TKIs, including ponatinib and olverembatinib, have been developed with the aim of overcoming drug resistance. Case report: A 79-year-old woman presented with intermittent fever and fatigue for 4 days. After comprehensive cytogenetic examination, the patient was diagnosed with Ph+-B-ALL. Starting on 22 September 2021, a combined regimen of flumatinib and vincristine/prednisone (VP) was administered for seven cycles, followed by flumatinib maintenance therapy. The patient remained in first complete molecular remission (1st CMR) for 19 months. On 12 March 2023, she again complained of fatigue and loss of appetite for nearly a month. A comprehensive examination showed Ph+-B-ALL relapse with additional E255V mutation, although T315I mutation was negative. In view of her frail physical condition, she received olverembatinib monotherapy and achieved second CMR (second CMR). No severe toxicities were recorded except for mild fatigue. At present, she has been in second CMR for over 6 months. Conclusion: For elderly patients with relapsed Ph+-ALL, olverembatinib monotherapy may offer a novel option with a good safety profile, suggesting the feasibility of a chemo-free regimen.

Histological transformation into SCLC: An important resistance mechanism of NSCLC upon immunotherapy.

The phenomenon of histological transformation has been widely reported in advanced non-small cell lung cancer (NSCLC) with EGFR mutations following the failure of EGFR-TKI treatment. Recent evidence suggests that similar histological changes can also occur in advanced NSCLC without driver gene mutations after developing resistance to immunotherapy. In this review, it was found that 66.7% of cases with immunotherapy-induced histological transformation were classified as lung squamous cell carcinoma (LSCC), while histological conversion into lung adenocarcinoma (LUAD) without EGFR or ALK gene mutations has rarely been reported. There have been sporadic reports on the occurrence of mutual transformation between LUAD and LSCC. The histological conversion from NSCLC into small cell lung cancer (SCLC) appears to be significantly underestimated, likely due to the infrequency of re-biopsy following the development of immunotherapy resistance. Several studies have reported a close association between the transformation and mutations at TP53 and the RB1 splice site, as well as the loss of an FBXW7 mutation. However, the exact mechanisms underlying this conversion remain unclear. Currently, there is a lack of guidelines for the management of transformed SCLC from NSCLC following immunotherapy, with chemotherapy being the most commonly employed treatment approach.

Etoposide/platinum plus anlotinib for patients with transformed small-cell lung cancer from EGFR-mutant lung adenocarcinoma after EGFR-TKI resistance: a retrospective and observational study.

Objective: The histological conversion of lung adenocarcinoma (LUAD) into small-cell lung cancer (SCLC) is an important resistance mechanism for epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI)-resistant LUAD. Anlotinib has been recommended as the third-line treatment for SCLC patients. The efficacy of etoposide/platinum (EP) as the main treatment is very limited for patients with transformed SCLC. However, little is known about EP plus anlotinib for transformed SCLC. The present study retrospectively explored the clinical response to EP combined with anlotinib in patients with transformed SCLC from LUAD after EGFR-TKI failure. Methods: A total of 10 patients who underwent SCLC transformation from EGFR-TKI-resistant LUAD were retrospectively reviewed from September 1, 2019, to December 31, 2022, in three regional hospitals. All of the patients were treated with the combination regimen of EP and anlotinib for four to six cycles, followed by anlotinib maintenance therapy. The clinical efficacy indices including objective response rate (ORR), disease control rate (DCR), median progression-free survival (mPFS), median overall survival (mOS), and toxicities were evaluated. Results: The median time from EGFR-TKI treatment to SCLC conversion was 20.1 ± 2.76 months (17-24 months). Genetic examination after transformation showed that 90% of the patients retained their original EGFR gene mutations. Additional driver genes were found, including BRAF mutation (10%), PIK3CA mutation (20%), RB1 loss (50%), and TP53 mutation (60%). The ORR and DCR were 80% and 100%, respectively. The mPFS was 9.0 months (95% CI, 7.9-10.1 months), and the mOS was 14.0 months (95% CI, 12.0-15.9 months). Less than 10% of grade 3 toxicities were observed, and no grade 4 toxicity and death events were reported. Conclusion: The EP plus anlotinib regimen appears to be a promising and safe strategy in transformed SCLC patients after EGFR-TKI resistance, which warrants further investigation.

A novel prednisone premedication protocol significantly decreases infusion­related reactions of rituximab in newly diagnosed diffuse large B­cell lymphoma.

Rituximab is a widely used anti-CD20 monoclonal antibody with a high incidence of infusion-related reactions (IRRs) during administration. Reducing the incidence of IRRs remains problematic in hematological practices. In the present study, a novel strategy of a prednisone pretreatment regimen was designed similar to the combination of rituximab, cyclophosphamide, epirubicin, vincristine and prednisone (R-CHOP) with the aim of exploring the effect on the incidence of IRRs to rituximab in patients with diffuse large B-cell lymphoma (DLBCL). A prospective, randomized (1:1) and controlled study was conducted in three regional hospitals in two groups (n=44 for each group): i) A control group treated with standard R-CHOP-like regimen; and ii) a group receiving a prednisone-pretreatment, modified R-CHOP-like protocol for newly diagnosed patients with DLBCL. The primary endpoint was to assess the incidence of IRRs to rituximab, as well as the association of IRRs with the efficacy of treatment. The second endpoint involved clinical outcomes. The total incidence of IRRs to rituximab in the treatment group was significantly lower compared with that in the control group (15.9 vs. 43.2%; P=0.0051). The different grade incidence of IRRs was lower in the treatment group compared with that in the control group (P=0.0053). In total, 29.5% of patients (26/88) experienced >1 IRR episode. The incidence of IRRs in the pre-treatment group was decreased compared with that in the control group in the 1st cycle (15.9 vs. 43.2%; P=0.0051) and 2nd cycle (6.8 vs. 27.3%; P=0.0107). The overall response rate was similar between the two groups (P>0.05). Median progression-free survival and median overall survival time were not statistically distinct between the two groups (P=0.5244 and P=0.5778, respectively). Grade ≥III toxicities mainly included vomiting and nausea (<20%), leukopenia and granulocytopenia (<20%), and alopecia (<25%). No death events were reported. Apart from IRRs to rituximab, the incidence of other adverse events was similar in both groups. The novel prednisone-pretreatment R-CHOP-like protocol in the present study significantly decreased the total and different grade incidences of IRRs to rituximab among newly diagnosed patients with DLBCL. This clinical trial was retrospectively registered with the Chinese Clinical Trial Registry (registration number, ChiCTR2300070327; date of registration, 10 April 2023).

[Effect of PKM2 on Osteogenic and Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells in Myeloma Bone Disease].

OBJECTIVE: To investigate the expression of pyruvate kinase M2 (PKM2) in bone marrow mesenchymal stem cells (BMSCs) in myeloma bone disease (MBD) and its effect on osteogenic and adipogenic differentiation of BMSCs. METHODS: BMSCs were isolated from bone marrow of five patients with multiple myeloma (MM) (MM group) and five with iron deficiency anemia (control group) for culture and identification. The expression of PKM2 protein were compared between the two groups. The differences between osteogenic and adipogenic differentiation of BMSCs were assessed by using alkaline phosphatase (ALP) and oil red O staining, and detecting marker genes of osteogenesis and adipogenesis. The effect of MM cell line (RPMI-8226) and BMSCs co-culture on the expression of PKM2 was explored. Functional analysis was performed to investigate the correlations of PKM2 expression of MM-derived BMSCs with osteogenic and adipogenic differentiation by employing PKM2 activator and inhibitor. The role of orlistat was explored in regulating PKM2 expression, osteogenic and adipogenic differentiation of MM-derived BMSCs. RESULTS: Compared with control, MM-originated BMSCs possessed the ability of increased adipogenic and decreased osteogenic differentiation, and higher level of PKM2 protein. Co-culture of MM cells with BMSCs markedly up-regulated the expression of PKM2 of BMSCs. Up-regulation of PKM2 expression could promote adipogenic differentiation and inhibit osteogenic differentiation of MM-derived BMSCs, while down-regulation of PKM2 showed opposite effect. Orlistat significantly promoted osteogenic differentiation in MM-derived BMSCs via inhibiting the expression of PKM2. CONCLUSION: The overexpression of PKM2 can induce the inhibition of osteogenic differentiation of BMSCs in MBD. Orlistat can promote the osteogenic differentiation of BMSCs via inhibiting the expression of PKM2, indicating a potential novel agent of anti-MBD therapy.

Immunotherapy-based therapy as a promising treatment for EGFR-mutant advanced non-small cell lung cancer patients after EGFR-TKI resistance.

INTRODUCTION: Traditionally, epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) has been regarded as a cold tumor based on the immunosuppressive tumor immune microenvironment (TIME). However, recent studies have found that EGFR-tyrosine kinase inhibitor (EGFR-TKI) treatment could shift host immunity from immunosuppressive to immunosupportive TIME, which has renewed hopes of immunotherapy. AREAS COVERED: In this review, we highlight five main immunotherapy-based therapies for patients after EGFR-TKI failure, including safety and efficacy data from prospective and retrospective clinical studies. EXPERT OPINION: The efficacy of immunotherapy alone is extremely limited. Immunotherapy plus chemotherapy show an ORR of 29.5%-59.3% and an mPFS of about 7 months. There is still scarce evidence for immunotherapy plus antiangiogenesis therapy. A combination of immunotherapy with EGFR-TKIs exhibits higher treatment-related adverse events and lower clinical outcomes compared to EGFR-TKI alone. Importantly, immunotherapy plus antiangiogenesis and chemotherapy achieves an mPFS of 6.9-10.2 months. In general, the strategy of combining immunotherapy with chemotherapy and/or an antiangiogenic drug is a novel and promising method for treating advanced NSCLC after EGFR-TKI failure. Therefore, the dominant population of EGFR-TKI resistant patients were characterized by EGFR uncommon mutation, EGFR L858R mutation, PD-L1 ≥ 50%, prior antiangiogenic drugs, and negative T790 M mutation for immunotherapy-based therapy.

Aumolertinib challenge as an optional treatment in advanced non small-cell lung cancer after osimertinib failure with epidermal growth factor receptor-sensitive mutation: A case series.

Osimertinib, as the first third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), has been recommended universally as the priority front-line therapeutic for advanced non-small cell lung cancer (NSCLC) carrying EGFR-sensitive mutations. However, patients inevitably acquire drug resistance to osimertinib. Aumolertinib is the second third-generation EGFR-TKI and has been similarly approved as a first-line treatment agent. The present study reports the cases of 3 patients who were challenged with aumolertinib after osimertinib failure. All 3 patients achieved a partial remission. The progression-free survival periods following aumolertinib were 10.0, 11 and 9.0 months (at the time of writing the study). Although the patient in case 2 succumbed to an intracerebral hemorrhage due to hypertension, aumolertinib remained effective as a treatment in cases 1 and 3. The present case series suggests the use of aumolertinib challenge as an optional treatment for patients with metastatic NSCLC harboring EGFR-sensitive mutations after osimertinib failure. The therapeutic strategy of switching from osimertinib to aumolertinib is worth exploring further in the near future.

LPCAT1 promotes gefitinib resistance via upregulation of the EGFR/PI3K/AKT signaling pathway in lung adenocarcinoma.

Currently, the mechanisms of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) resistance have been a focus of clinical research. Despite that most of the mechanisms of acquired EGFR TKI resistance have been revealed, about 30% of non-small-cell lung cancer (NSCLC) cases have not been fully elucidated, especially for lung adenocarcinoma (LUAD). Recently, LPCAT1, an important enzyme of phospholipid metabolism, has been found to bridge the gap between the oncogene and metabolic reprogramming. In NSCLC, LPCAT1 has been shown to participate in progression and metastasis. However, little is known about the role of LPCAT1 in acquired EGFR TKI resistance. In this study, elevated LPCAT1 expressions were observed in an EGFR TKI-resistant cell line (PC-9R) relative to a corresponding EGFR TKI-sensitive cell line (PC-9). In vivo and in vitro gene functional studies showed that LPCAT1 contributed to the pathogenesis of gefitinib resistance in LUAD, where an LPCAT1-EGFR positive feedback loop formed and then regulated its downstream signaling molecules of the EGFR/PI3K/AKT signaling pathway. The results provided novel insights into the acquired resistance mechanism of EGFR TKI from the perspective of phospholipid metabolism. These findings suggest LPCAT1 may serve as a potential therapeutic target for patients with EGFR TKI-resistant NSCLC.

Decreased serum apolipoprotein A1 level predicts poor prognosis of patients with de novo myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) is a group of heterogeneous myeloid clonal diseases originating from hematopoietic stem cells. It has been demonstrated that apolipoproteins A1(ApoA1) are associated with disease risk in many cancer types. However, there still lacks evidence regarding the link between ApoA1 and MDS. This study was designed to investigate the prognostic value of pretreatment ApoA1 levels in MDS patients. METHODS: We retrospectively analyzed a cohort of 228 MDS patients to explore the prognostic value of the serum ApoA1 levels at diagnosis. Patients were divided into the high ApoA1 group and the low ApoA1 group. The prognostic significance was determined by univariate and multivariate Cox hazard models. RESULTS: MDS patients with low ApoA1 levels had significantly shorter overall survival (OS, P < 0.0001) along with a higher frequency of TP53 mutation (P = 0.002). Based on univariate analysis, age (≥ 60 years), gender (male), lower levels of hemoglobin (< 10 g/dl), HDL (≤0.91 mmol/L), higher bone marrow blast percentage (> 5%), higher IPSS-R scores and poorer karyotype were significantly associated with decreased OS. However, low ApoA1 level did not influence leukemia-free survival (LFS, P = 0.367). Multivariate Cox proportional hazards regression analysis indicated that low ApoA1 level (≤ 1.02 g/L) was also an independent adverse prognostic factor for OS in MDS (P = 0.034). CONCLUSIONS: Decreased ApoA1 level predicts a poor prognosis of MDS patients and thus provides a novel evaluation factor for them that is independent of the IPSS-R system.

Long-acting granulocyte colony-stimulating factor in primary prophylaxis of early infection in patients with newly diagnosed multiple myeloma.

PURPOSE: This study sought to compare the efficacy of prophylactic long-acting and standard granulocyte colony-stimulating factor (G-CSF) on febrile neutropenia, early infections, and treatment delay in patients with newly diagnosed multiple myeloma (MM) receiving the therapeutic regimen of bortezomib, lenalidomide, and dexamethasone (VRd). METHODS: A prospective study with 68 consecutive patients with MM was conducted in three regional hospitals. Participants were randomly treated with the VRd regimen in combination with prophylactic long-acting G-CSF (treatment group) or prophylactic standard G-CSF (control group). The primary endpoints were the incidence rates of febrile neutropenia, early infection, and treatment delays. The secondary endpoint was clinical outcomes. RESULTS: Thirty-three patients were assigned to the treatment group, and thirty-five patients were assigned to the control group. The incidence of febrile neutropenia was 6.1% and 17.1% in the treatment and control groups, respectively (p = 0.297). However, the rates of early infection and treatment delay were markedly lower in the treatment group than in the control group (6.1% vs. 25.7% and 9.1% vs. 31.4%; p < 0.05). Notably, all early infections occurred during the first four cycles of VRd therapy, and the most common type of infection was pneumonia. No significant difference in clinical efficacy was found between the two groups. All participants achieved at least partial remission. CONCLUSIONS: Prophylactic administration of domestic long-acting G-CSF markedly reduced the rates of early infection and treatment delay as compared with standard G-CSF in patients newly diagnosed with MM. Notably, all early infections occurred during the first four cycles of VRd therapy. As such, it seems appropriate to administer long-acting G-CSF with the aim of primary prophylaxis of early infection in the setting of newly diagnosed MM.

Effective treatment of apatinib for chemotherapy-refractory advanced gastric carcinoma with AFP-secretion and HER2-positivity: A case report.

α-fetoprotein (AFP)-secreting gastric cancer (AFP-GC) is a relatively rare, aggressive malignancy among all GC types. However, no GC case with simultaneous expression of AFP and epidermal growth factor receptor 2 (HER2) has been reported to date. To the best of our knowledge, the present report was the first to describe the use of apatinib to treat a patient with advanced GC characterized by AFP-secretion and HER2-positivity. An 86-year-old man with advanced GC was diagnosed with AFP-secretive and HER2-positive GC with liver metastasis at The Affiliated Hospital of Jiujiang University (Jiujiang, China). The patient received first-line (i.e., S-1 plus oxaliplatin) and second-line (i.e., docetaxel) chemotherapy combined with trastuzumab for two cycles, respectively. However, the disease progressed rapidly. Subsequently, apatinib was administered as third-line therapy. After two cycles of apatinib therapy, the patient reported the disappearance of upper abdominal pain and an improvement in his appetite. Furthermore, the AFP level had sharply decreased to 620 ng/ml. Subsequently, upper abdominal computed tomography imaging revealed that the gastric lesion and liver metastatic lesion had reduced in size by 67% and 24%, respectively, suggesting partial remission. Currently, the patient has continued to receive apatinib therapy. It was speculated that AFP-secretion status could contribute to the chemoresistance of HER2-positive GC. Apatinib may be a promising anticancer agent in the case of advanced AFP-producing and HER2-positive GC.

Effects of microRNA­125b on multiple myeloma cell growth in vitro and in vivo.

Multiple myeloma (MM) is a heterogeneous disease with a poor prognosis. The expression of microRNA­125b (miR­125b), a novel oncomiR, is elevated in various cancer types. The present study found that the expression of miR­125b was increased in plasma samples from 35 patients with MM, compared with that in samples from 20 healthy controls, by performing real­time PCR. CCK­8 assay, migration and invasion assay showed that the downregulation of miR­125b inhibited cell proliferation and migration and reduced the levels of phosphorylated Akt, compared with those of the blank and negative control groups. Dual­Luciferase activity assay demonstrated that the tumor suppressor PH domain and leucine rich repeat protein phosphatase 2 (PHLPP2) was a target of miR­125b, which inhibited PHLPP2 and directly bound to the 3'untranslated region of PHLPP2, resulting in elevated Akt signaling. Furthermore, the expression of a miR­125b inhibitor in MM cells in a xenograft mouse model suppressed tumor growth. These results showed that the inhibition of miR­125b suppressed MM progression by inhibiting Akt signaling, and suggested that miR­125b may be a novel molecular therapeutic target for MM treatment.

Aspirin enhances the cytotoxic activity of bortezomib against myeloma cells via suppression of Bcl-2, survivin and phosphorylation of AKT.

In our previous study, it was found that aspirin (ASA) exerted antimyeloma actions in vivo and in vitro. The resistance to bortezomib (BTZ) in multiple myeloma (MM) is partly due to AKT activation and the upregulation of survivin induced by BTZ, which are the targets of ASA in gastric and ovarian cancer, respectively. Thus, the present study investigated the interaction between ASA and BTZ in MM and further clarified the underlying mechanisms. MM1.S and RPMI-8226 cell lines harboring the N- and K-Ras mutations, respectively, were treated with 2.5 mM ASA, 10 nM BTZ and ASA+BTZ for different durations. The proliferation and apoptosis of the cells were determined, and the underlying mechanisms governing the interaction of ASA and BTZ were examined in the MM cells. Treatment with ASA+BTZ caused higher rates of proliferative inhibition and apoptosis in the MM1.S and RPMI-8226 cells in time-dependent manner, compared with either agent alone. A drug interaction assay revealed the additive effect of ASA and BTZ on the myeloma cells. ASA alone inhibited the levels of phosphorylated AKT (p-AKT) and survivin, whereas BTZ alone augmented the levels of p-AKT and survivin. Of note, ASA markedly decreased the upregulation of p-AKT and survivin induced by BTZ. Treatment with ASA+BTZ significantly suppressed the level of Bcl-2, compared with either agent alone. ASA may potentiate the antimyeloma activity of BTZ against myeloma cells via suppression of AKT phosphorylation, survivin and Bcl-2, indicating the potential of ASA+BTZ in treating MM, particularly for cases of BTZ-refractory/relapsed MM.

Multiple myeloma acquires resistance to EGFR inhibitor via induction of pentose phosphate pathway.

Multiple myeloma (MM) was characterized by frequent mutations in KRAS/NRAS/BRAF within the EGFR pathway that could induce resistance to EGFR inhibitors. We here report that EGFR inhibition solely exhibited moderate inhibition in KRAS/NRAS/BRAF wildtype (triple-WT) MM cells, whilst had no effect in myeloma cells with any of the mutated genes. The moderate inhibitory effect was conferred by induction of pentose phosphate pathway (PPP) when cells were treated with Gefitinib, the EGFR inhibitor. Combination of Gefitinib with PPP inhibitor 6AN effected synergistically in triple-WT cells. The inhibition could be restored by addition of NADPH. Dual EGFR/ERBB2 inhibitor Afatinib also exhibited similar effects. Further genetic silencing of EGFR, ERBB2 and mTOR indicated that major effect conferred by ERBB2 was via convergence to EGFR pathway in MM. Our results contributed to the individualized targeted therapy with EGFR inhibitors in MM.

Aspirin inhibits proliferation and induces apoptosis of multiple myeloma cells through regulation of Bcl-2 and Bax and suppression of VEGF.

OBJECTIVES: Aspirin (ASA) has been frequently used for thromboprophylaxis in patients with multiple myeloma (MM) when treated with thalidomide or lenalidomide. Despite the well-recognized chemopreventive role of ASA in some solid tumors particularly for colon cancer, whether ASA displays the antimyeloma activity remains unclear. METHODS: MM1.S and RPMI-8226 cell lines harboring K-Ras and N-Ras mutation, respectively, were treated with various concentrations of ASA for different hours. The cell proliferation and apoptosis were performed to explore the effects of ASA on myeloma. Then, the exact mechanisms governing ASA's antimyeloma were explored by qRT-PCR and Western blot. Also, the effect of ASA on tumor growth was observed in NOD/SCID mice bearing myeloma xenografts. RESULTS: ASA of 0-10 mm concentration inhibits proliferation MM1.S and RPMI-8226 cells in time- and dose-dependent manner. The myeloma cells exposed to ASA treatment displayed concentration-dependent apoptosis, which was closely associated with activation of caspases, upregulation of Bax, and downregulation of Bcl-2 and VEGF. Study in vivo revealed that ASA administration retarded the tumor growth accompanying the survival time of mice bearing myeloma xenografts. CONCLUSIONS: ASA exerted antiproliferative and pro-apoptotic action in myeloma cells in vitro and delayed the growth of human myeloma cells in vivo. The underlying mechanisms were ascribed to regulation of Bcl-2 and Bax and suppression of VEGF.