The Cell that Caused Melanoma: Cancer’s Surprise Origins, Caught in Action

This post originally appeared on Vector, Boston Children’s Hospital’s science and clinical innovation blog. It’s long been a mystery why some of our cells can have mutations associated with cancer, yet are not truly cancerous. Now researchers have, for the first time, watched a cancer spread from a single cell in a live animal, and … Read more

What Is CTLA-4 and How Does it Work in Treating Metastatic Melanoma?

Since the early 2000s, when Dana-Farber scientists discovered that many cancer cells carry “checkpoint” proteins that ward off an immune system attack on tumors, a great deal of research has focused on the development and testing of agents capable of blocking those proteins. In many patients, such agents have sent cancers into long-term remissions. A checkpoint … Read more

Remission of Jimmy Carter’s Melanoma Shows Potential of Immunotherapy for Cancer

Former President Jimmy Carter’s announcement earlier this week that he is free of the melanoma that had spread to his liver and brain may be the highest-profile example yet of the promise of a new form of cancer treatment that unleashes an immune system attack on the disease. Carter, 91, was treated with radiation therapy … Read more

Does Having More Moles Increase My Risk of Melanoma?

Moles are benign growths on the skin that sometimes become cancerous. But what exactly is the connection between moles and melanoma, the most aggressive skin cancer? While it’s true that people with many moles should be screened more frequently by a dermatologist, scientists are learning that the mole-melanoma connection isn’t so straightforward. For example, a … Read more

FDA Approves Targeted Therapy Combination for Melanoma

Just over a month after approving a first-of-its-kind combination therapy for advanced melanoma, the U.S. Food and Drug Administration (FDA) has signed off on another drug combination to treat the disease. The FDA has approved a targeted therapy combination, Cotellic (cobimetinib) and vemurafenib, to treat advanced melanoma that has spread to other parts of the … Read more

FDA Approves Immunotherapy Drug Combination for Melanoma

This blog post originally appeared on Cancer Research Catalyst, the official blog of the American Association for Cancer Research. By Karen Honey, PhD Last week, new ground was broken in the field of cancer immunotherapy when the U.S. Food and Drug Administration (FDA) approved the first cancer treatment to combine two of these cutting-edge agents: … Read more

Melanoma – What’s the Latest?

Sun safety applies to everyone, regardless of skin color, gender, or age. That was the message emphasized in a recent live video webchat with Dana-Farber/Brigham and Women’s Cancer Center (DF/BWCC) dermatologist Jennifer Lin, MD. During the chat, Lin answered questions about the latest in melanoma treatment and prevention. “The bottom line is that UV radiation … Read more

Can Kids Get Melanoma? What Parents Need to Know

Medically reviewed by Carlos Rodriguez-Galindo, MD Although melanoma is more commonly found in adults, childhood and adolescent melanoma affects approximately 300 children in the U.S. each year. Thankfully, the incidence rate has started to decrease in recent years. While melanoma is the least common type of skin cancer in adults, skin cancer in children is almost … Read more

Promising Research Developments Stir Hopes for Melanoma, Lung, Breast and Ovarian Cancer

The growing excitement about the potential of immunotherapy treatments for cancer continued at the 2015 meeting of the American Association for Cancer Research (AACR), one of the largest cancer research meetings of the year. Several Dana-Farber investigators presented encouraging results of immunotherapy for melanoma, lung cancer, and breast cancer. F. Stephen Hodi, MD, and Leena … Read more

Can Melanoma Affect Any Skin Type?

Melanoma, the deadliest skin cancer, gets its name from the pigment-producing cells called melanocytes from which tumors can develop. These cells manufacture the dark pigment, melanin. When a human develops these cells, they populate not only the skin, but also other organs including the back of the eye and the nervous system. Melanin strongly absorbs … Read more

Research Report: New Treatments for Melanoma

As recently as five years ago, progress in treating life-threatening malignant melanoma was slow. Since then, several molecularly targeted drugs have burst on the scene, and new strategies for awakening the immune system to attack the cancer cells have yielded dramatic long-term survival benefits for some patients. “The outlook for patients has never been so … Read more

什么是细胞周期?它与癌症有什么关系? 

发布日期:2023年5月16日  医学审校:Robert J. Mayer博士(Robert J. Mayer, MD)  细胞周期包含一系列步骤,包括:活细胞生长、复制其DNA,并分裂成两个相同的子代细胞,每个子细胞获得母本的一份拷贝。当每个子细胞被封存在自身的膜内时,细胞周期完成,为开启新的细胞周期做好准备。  细胞周期以一种精确运转的方式展开,确保细胞将DNA的精准拷贝遗传给其子代细胞。在分裂前的DNA复制或DNA迁移到新形成的细胞的过程中,如果出现任何错误,那么细胞的遗传程序都会出错,从而导致癌症或其他疾病的产生。  细胞周期的分期(Stage)  在含有细胞核的细胞内,细胞周期有5个分期:  G0期:细胞尚未分裂,在体内中正常运作  G1期(gap 1):细胞生长  S期 (synthesis 合成) :细胞复制其DNA  G2期 (gap 2) :细胞准备分裂  M期 (mitosis 有丝分裂) :细胞核(nucleus)和细胞质(cytoplasm)分裂,形成两个子代细胞  人体细胞用90%的时间完成前三个分期, 统称分裂间期(interphase)。  细胞周期的持续时间因细胞类型而异。大部分人体细胞在24小时左右完成周期。快速生长的细胞(如肠道内壁细胞)或在9-10小时内完成分期,而肝细胞的分期则超过一年,神经细胞的分期则需更多年完成。 细胞分期和癌症   在细胞周期任何阶段出现的失误或错误——特别是在DNA复制或DNA分配给子细胞的过程中出错,都会驱使细胞向产生癌变的方向演化。  细胞周期含有若干检查点,其作用类似流水线上的阀门,让细胞“扫描”问题并采取必要的修复措施。细胞借此机会来确认自身生长到应有的大小、正确地复制了自身的DNA、准确地排列了用于分裂的染色体。细胞或修复错误,但如果严重的话,细胞也会通过自毁的方式避免将自身的错误传给后代。  若干蛋白质控制检查点,其中最重要的检查点之一是p53,它在细胞周期中主要在G1检查点上作用。当一个细胞的DNA受损时,一个蛋白质激活p53,p53终止细胞周期并下达修复的指令,如果出现不可修复的损伤,p53会引起细胞消亡。p53对健康细胞的延续而言至关重要,它也被视为基因组的护卫。  如果p53消失、发生故障或者比活性低于正常水平,它或许会让携带受损DNA的一个细胞进入细胞周期的下一阶段,增加DNA拼写错误且遗传给子细胞的几率。这种错误在多个细胞周期中不断累积,就会向癌症迈进一步。p53 是人类癌症中最常见的突变基因。  化疗如何影响细胞周期?  在细胞周期的不同阶段,不同类型的化疗(chemotherapy)药物会对癌细胞发起攻击。  有些化疗药物对细胞周期的一个特定阶段作用。例如,抗代谢药(antimetabolite)和叶酸拮抗剂(antifol)就以S期为靶点,干扰DNA分子的构建。博来霉素(bleomycin)和依托泊苷(etoposide)和其它药物则以G2期为靶点,使DNA断裂;长春花生物碱类(vinca alkaloids)以M期为靶点,防止染色体在细胞分裂的过程中正确排列。  还有一些药物可作用于分裂中的细胞,无论细胞周期。这些药物包括:烷化剂(alkylating agents)——与DNA结合并阻止DNA复制;嵌入剂(intercalators)——起作用是扭曲DNA双螺旋的正常形状和结构。  第三类药物对癌细胞作用显著,无论癌细胞处在细胞周期的何种阶段。这些药物包括:皮质类固醇(corticosteroids)和激素拮抗剂(hormone antagonists),其作用机制是与细胞受体结合,防止细胞接收到生长信号。  放疗如何影响细胞周期?  辐射会杀死处于积极分裂中的细胞,即不处于G0期的细胞。因为癌细胞无序生长,与正常细胞相比,它们或需要更多的时间完成分裂,所以癌细胞特别容易受到放疗的影响。  靶向治疗如何干预细胞周期?  靶向疗法(targeted therapies)是一组抑制与癌症有关的特异性细胞蛋白质的药物。靶向疗法的药物有一部分作为标准治疗用药,有一些尚处于临床试验中,其核心聚焦于在细胞周期中起到关键作用的蛋白质。  以CDK4和CDK6蛋白质为例,这两种蛋白质在细胞周期的一个重要节点扮演着保护的作用,即细胞从G0期和G1期向S期过渡。在有些癌症病种中,CDK4和CDK6蛋白质的异常会使细胞分裂进入高速运转的状态。以CDK4/6抑制剂(CDK4/6 inhibitors)为代表的的药物干扰这些蛋白质,有助于阻止细胞周期的展开。在某些情况下,癌细胞不仅停止分裂,还会丧失所有用于循环和生长的能力,使得肿瘤缩小。CDK4/6抑制剂在治疗晚期雌激素受体阳性和HER2-阴性乳腺癌(advanced estrogen receptor-positive and HER2-negative breast … Read more